diff --git a/src/Admin.vue b/src/Admin.vue
index 182d4a6d..2b36deb8 100644
--- a/src/Admin.vue
+++ b/src/Admin.vue
@@ -641,7 +641,7 @@ export default defineComponent({
 
     loading: 0,
 
-    status: null as IStatus,
+    status: null as IStatus | null,
   }),
 
   mounted() {
@@ -680,7 +680,7 @@ export default defineComponent({
       }
     },
 
-    async update(key: string, value = null) {
+    async update(key: string, value: any = null) {
       value = value ?? this[key];
       const setting = settings[key];
 
@@ -727,7 +727,7 @@ export default defineComponent({
         "This may also cause all photos to be re-indexed!"
       );
       const msg =
-        (this.status.gis_count ? warnSetup : warnLong) + " " + warnReindex;
+        (this.status?.gis_count ? warnSetup : warnLong) + " " + warnReindex;
       if (!confirm(msg)) {
         event.preventDefault();
         event.stopPropagation();
@@ -805,6 +805,8 @@ export default defineComponent({
     },
 
     gisStatus() {
+      if (!this.status) return "";
+
       if (typeof this.status.gis_type !== "number") {
         return this.status.gis_type;
       }
@@ -825,7 +827,7 @@ export default defineComponent({
     },
 
     gisStatusType() {
-      return typeof this.status.gis_type !== "number" ||
+      return typeof this.status?.gis_type !== "number" ||
         this.status.gis_type <= 0
         ? "error"
         : "success";
@@ -836,6 +838,8 @@ export default defineComponent({
     },
 
     vaapiStatusText(): string {
+      if (!this.status) return "";
+
       const dev = "/dev/dri/renderD128";
       if (this.status.vaapi_dev === "ok") {
         return this.t("memories", "VA-API device ({dev}) is readable", { dev });
@@ -855,7 +859,7 @@ export default defineComponent({
     },
 
     vaapiStatusType(): string {
-      return this.status.vaapi_dev === "ok" ? "success" : "error";
+      return this.status?.vaapi_dev === "ok" ? "success" : "error";
     },
   },
 });
diff --git a/src/App.vue b/src/App.vue
index afcd6139..36bebf09 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -89,6 +89,13 @@ import TagsIcon from "vue-material-design-icons/Tag.vue";
 import MapIcon from "vue-material-design-icons/Map.vue";
 import CogIcon from "vue-material-design-icons/Cog.vue";
 
+type NavItem = {
+  name: string;
+  title: string;
+  icon: any;
+  if?: any;
+};
+
 export default defineComponent({
   name: "App",
   components: {
@@ -122,7 +129,7 @@ export default defineComponent({
   mixins: [UserConfig],
 
   data: () => ({
-    navItems: [],
+    navItems: [] as NavItem[],
     metadataComponent: null as any,
     settingsOpen: false,
   }),
@@ -133,7 +140,7 @@ export default defineComponent({
       return Number(version[0]);
     },
 
-    recognize(): string | boolean {
+    recognize(): string | false {
       if (!this.config_recognizeEnabled) {
         return false;
       }
@@ -145,7 +152,7 @@ export default defineComponent({
       return t("memories", "People");
     },
 
-    facerecognition(): string | boolean {
+    facerecognition(): string | false {
       if (!this.config_facerecognitionInstalled) {
         return false;
       }
@@ -189,7 +196,7 @@ export default defineComponent({
     const onResize = () => {
       globalThis.windowInnerWidth = window.innerWidth;
       globalThis.windowInnerHeight = window.innerHeight;
-      emit("memories:window:resize", null);
+      emit("memories:window:resize", {});
     };
     window.addEventListener("resize", () => {
       utils.setRenewingTimeout(this, "resizeTimer", onResize, 100);
@@ -258,7 +265,7 @@ export default defineComponent({
   },
 
   methods: {
-    navItemsAll() {
+    navItemsAll(): NavItem[] {
       return [
         {
           name: "timeline",
@@ -289,13 +296,13 @@ export default defineComponent({
         {
           name: "recognize",
           icon: PeopleIcon,
-          title: this.recognize,
+          title: this.recognize || "",
           if: this.recognize,
         },
         {
           name: "facerecognition",
           icon: PeopleIcon,
-          title: this.facerecognition,
+          title: this.facerecognition || "",
           if: this.facerecognition,
         },
         {
@@ -334,7 +341,7 @@ export default defineComponent({
     },
 
     doRouteChecks() {
-      if (this.$route.name.endsWith("-share")) {
+      if (this.$route.name?.endsWith("-share")) {
         this.putShareToken(<string>this.$route.params.token);
       }
     },
diff --git a/src/components/ClusterGrid.vue b/src/components/ClusterGrid.vue
index e7250cf6..77a0921c 100644
--- a/src/components/ClusterGrid.vue
+++ b/src/components/ClusterGrid.vue
@@ -23,7 +23,7 @@
 <script lang="ts">
 import { defineComponent } from "vue";
 import Cluster from "./frame/Cluster.vue";
-import { ICluster } from "../types";
+import type { ICluster } from "../types";
 
 export default defineComponent({
   name: "ClusterGrid",
diff --git a/src/components/ClusterView.vue b/src/components/ClusterView.vue
index e64ef3b6..0dea7ed4 100644
--- a/src/components/ClusterView.vue
+++ b/src/components/ClusterView.vue
@@ -21,7 +21,7 @@ import EmptyContent from "./top-matter/EmptyContent.vue";
 
 import * as dav from "../services/DavRequests";
 
-import { ICluster } from "../types";
+import type { ICluster } from "../types";
 
 export default defineComponent({
   name: "ClusterView",
diff --git a/src/components/FirstStart.vue b/src/components/FirstStart.vue
index c36db3ed..08460c14 100644
--- a/src/components/FirstStart.vue
+++ b/src/components/FirstStart.vue
@@ -59,7 +59,7 @@ import { getCurrentUser } from "@nextcloud/auth";
 import axios from "@nextcloud/axios";
 
 import banner from "../assets/banner.svg";
-import { IDay } from "../types";
+import type { IDay } from "../types";
 import { API } from "../services/API";
 
 export default defineComponent({
diff --git a/src/components/FolderGrid.vue b/src/components/FolderGrid.vue
index 8b565d54..a23a26e6 100644
--- a/src/components/FolderGrid.vue
+++ b/src/components/FolderGrid.vue
@@ -12,7 +12,7 @@ import { defineComponent } from "vue";
 import UserConfig from "../mixins/UserConfig";
 import Folder from "./frame/Folder.vue";
 
-import { IFolder } from "../types";
+import type { IFolder } from "../types";
 
 export default defineComponent({
   name: "ClusterGrid",
diff --git a/src/components/Metadata.vue b/src/components/Metadata.vue
index 94298cb8..e59d5878 100644
--- a/src/components/Metadata.vue
+++ b/src/components/Metadata.vue
@@ -29,7 +29,7 @@
         <NcActions :inline="1">
           <NcActionButton
             :aria-label="t('memories', 'Edit')"
-            @click="field.edit()"
+            @click="field.edit?.()"
           >
             {{ t("memories", "Edit") }}
             <template #icon> <EditIcon :size="20" /> </template>
@@ -72,7 +72,7 @@ import InfoIcon from "vue-material-design-icons/InformationOutline.vue";
 import LocationIcon from "vue-material-design-icons/MapMarker.vue";
 import TagIcon from "vue-material-design-icons/Tag.vue";
 import { API } from "../services/API";
-import { IImageInfo } from "../types";
+import type { IImageInfo } from "../types";
 
 interface TopField {
   title: string;
@@ -112,8 +112,8 @@ export default defineComponent({
 
       if (this.dateOriginal) {
         list.push({
-          title: this.dateOriginalStr,
-          subtitle: this.dateOriginalTime,
+          title: this.dateOriginalStr!,
+          subtitle: this.dateOriginalTime!,
           icon: CalendarIcon,
           edit: () =>
             globalThis.editMetadata([globalThis.currentViewerPhoto], [1]),
@@ -228,13 +228,13 @@ export default defineComponent({
       return `${make} ${model}`;
     },
 
-    cameraSub(): string[] | null {
+    cameraSub(): string[] {
       const f = this.exif["FNumber"] || this.exif["Aperture"];
       const s = this.shutterSpeed;
       const len = this.exif["FocalLength"];
       const iso = this.exif["ISO"];
 
-      const parts = [];
+      const parts: string[] = [];
       if (f) parts.push(`f/${f}`);
       if (s) parts.push(`${s}`);
       if (len) parts.push(`${len}mm`);
@@ -263,8 +263,8 @@ export default defineComponent({
       return this.baseInfo.basename;
     },
 
-    imageInfoSub(): string[] | null {
-      let parts = [];
+    imageInfoSub(): string[] {
+      let parts: string[] = [];
       let mp = Number(this.exif["Megapixels"]);
 
       if (this.baseInfo.w && this.baseInfo.h) {
@@ -282,7 +282,7 @@ export default defineComponent({
       return parts;
     },
 
-    address(): string | null {
+    address(): string | undefined {
       return this.baseInfo.address;
     },
 
@@ -298,11 +298,11 @@ export default defineComponent({
       return Object.values(this.baseInfo?.tags || {});
     },
 
-    tagNamesStr(): string {
+    tagNamesStr(): string | null {
       return this.tagNames.length > 0 ? this.tagNames.join(", ") : null;
     },
 
-    mapUrl(): string | null {
+    mapUrl(): string {
       const boxSize = 0.0075;
       const bbox = [
         this.lon - boxSize,
@@ -314,7 +314,7 @@ export default defineComponent({
       return `https://www.openstreetmap.org/export/embed.html?bbox=${bbox.join()}&marker=${m}`;
     },
 
-    mapFullUrl(): string | null {
+    mapFullUrl(): string {
       return `https://www.openstreetmap.org/?mlat=${this.lat}&mlon=${this.lon}#map=18/${this.lat}/${this.lon}`;
     },
   },
@@ -336,7 +336,7 @@ export default defineComponent({
       return this.baseInfo;
     },
 
-    handleFileUpdated({ fileid }) {
+    handleFileUpdated({ fileid }: { fileid: number }) {
       if (fileid && this.fileid === fileid) {
         this.update(this.fileid);
       }
diff --git a/src/components/ScrollerManager.vue b/src/components/ScrollerManager.vue
index 34b1f001..be2db507 100644
--- a/src/components/ScrollerManager.vue
+++ b/src/components/ScrollerManager.vue
@@ -66,13 +66,25 @@ export default defineComponent({
 
   props: {
     /** Rows from Timeline */
-    rows: Array as PropType<IRow[]>,
+    rows: {
+      type: Array as PropType<IRow[]>,
+      required: true,
+    },
     /** Total height */
-    height: Number,
+    height: {
+      type: Number,
+      required: true,
+    },
     /** Actual recycler component */
-    recycler: Object,
+    recycler: {
+      type: Object,
+      required: false,
+    },
     /** Recycler before slot component */
-    recyclerBefore: HTMLDivElement,
+    recyclerBefore: {
+      type: HTMLDivElement,
+      required: false,
+    },
   },
 
   data: () => ({
@@ -81,7 +93,7 @@ export default defineComponent({
     /** Height of the entire photo view */
     recyclerHeight: 100,
     /** Rect of scroller */
-    scrollerRect: null as DOMRect,
+    scrollerRect: null as DOMRect | null,
     /** Computed ticks */
     ticks: [] as ITick[],
     /** Computed cursor top */
@@ -273,8 +285,8 @@ export default defineComponent({
     /** Do adjustment synchronously */
     adjustNow() {
       // Refresh height of recycler
-      this.recyclerHeight = this.recycler.$refs.wrapper.clientHeight;
-      const extraY = this.recyclerBefore?.clientHeight || 0;
+      this.recyclerHeight = this.recycler?.$refs.wrapper.clientHeight ?? 0;
+      const extraY = this.recyclerBefore?.clientHeight ?? 0;
 
       // Start with the first tick. Walk over all rows counting the
       // y position. When you hit a row with the tick, update y and
@@ -417,7 +429,7 @@ export default defineComponent({
       }
 
       const date = utils.dayIdToDate(dayId);
-      this.hoverCursorText = utils.getShortDateStr(date);
+      this.hoverCursorText = utils.getShortDateStr(date) ?? "";
     },
 
     /** Handle mouse hover */
@@ -480,7 +492,7 @@ export default defineComponent({
 
       if (this.lastRequestedRecyclerY !== targetY) {
         this.lastRequestedRecyclerY = targetY;
-        this.recycler.scrollToPosition(targetY);
+        this.recycler?.scrollToPosition(targetY);
       }
 
       this.handleScroll();
@@ -494,6 +506,7 @@ export default defineComponent({
 
     /** Handle touch */
     touchmove(event: any) {
+      if (!this.scrollerRect) return;
       let y = event.targetTouches[0].pageY - this.scrollerRect.top;
       y = Math.max(0, y - 20); // middle of touch finger
       this.moveto(y, true);
diff --git a/src/components/SelectionManager.vue b/src/components/SelectionManager.vue
index 49d742dd..acaf189a 100644
--- a/src/components/SelectionManager.vue
+++ b/src/components/SelectionManager.vue
@@ -103,27 +103,39 @@ export default defineComponent({
   mixins: [UserConfig],
 
   props: {
-    heads: Object as PropType<{ [dayid: number]: IHeadRow }>,
+    heads: {
+      type: Object as PropType<{ [dayid: number]: IHeadRow }>,
+      required: true,
+    },
     /** List of rows for multi selection */
-    rows: Array as PropType<IRow[]>,
+    rows: {
+      type: Array as PropType<IRow[]>,
+      required: true,
+    },
     /** Rows are in ascending order (desc is normal) */
-    isreverse: Boolean,
+    isreverse: {
+      type: Boolean,
+      required: true,
+    },
     /** Recycler element to scroll during touch multi-select */
-    recycler: Object,
+    recycler: {
+      type: HTMLDivElement,
+      required: false,
+    },
   },
 
   data: () => ({
     show: false,
     size: 0,
     selection: new Map<number, IPhoto>(),
-    defaultActions: null as ISelectionAction[],
+    defaultActions: null! as ISelectionAction[],
 
-    touchAnchor: null as IPhoto,
-    prevTouch: null as Touch,
+    touchAnchor: null as IPhoto | null,
+    prevTouch: null as Touch | null,
     touchTimer: 0,
     touchMoved: false,
-    touchPrevSel: null as Selection,
-    prevOver: null as IPhoto,
+    touchPrevSel: null as Selection | null,
+    prevOver: null as IPhoto | null,
     touchScrollInterval: 0,
     touchScrollDelta: 0,
   }),
@@ -225,6 +237,14 @@ export default defineComponent({
       this.$emit("delete", photos);
     },
 
+    deleteSelectedPhotosById(delIds: number[], selection: Selection) {
+      return this.deletePhotos(
+        delIds
+          .map((id) => selection.get(id))
+          .filter((p): p is IPhoto => p !== undefined)
+      );
+    },
+
     updateLoading(delta: number) {
       this.$emit("updateLoading", delta);
     },
@@ -351,7 +371,7 @@ export default defineComponent({
       window.clearTimeout(this.touchTimer);
       this.touchTimer = 0;
       this.touchMoved = false;
-      this.prevOver = undefined;
+      this.prevOver = null;
 
       window.cancelAnimationFrame(this.touchScrollInterval);
       this.touchScrollInterval = 0;
@@ -419,7 +439,8 @@ export default defineComponent({
           let frameCount = 3;
 
           const fun = () => {
-            this.recycler.$el.scrollTop += this.touchScrollDelta;
+            if (!this.prevTouch) return;
+            this.recycler!.scrollTop += this.touchScrollDelta;
 
             if (frameCount++ >= 3) {
               this.touchMoveSelect(this.prevTouch, rowIdx);
@@ -442,11 +463,14 @@ export default defineComponent({
 
     /** Multi-select triggered by touchmove */
     touchMoveSelect(touch: Touch, rowIdx: number) {
+      // Assertions
+      if (!this.touchAnchor) return;
+
       // Which photo is the cursor over, if any
       const elem: any = document
         .elementFromPoint(touch.clientX, touch.clientY)
         ?.closest(".p-outer-super");
-      let overPhoto: IPhoto = elem?.__vue__?.data;
+      let overPhoto: IPhoto | null = elem?.__vue__?.data;
       if (overPhoto && overPhoto.flag & this.c.FLAG_PLACEHOLDER)
         overPhoto = null;
 
@@ -460,7 +484,8 @@ export default defineComponent({
         // days reverse XOR rows reverse
         let reverse: boolean;
         if (overPhoto.dayid === this.touchAnchor.dayid) {
-          const l = overPhoto.d.detail;
+          const l = overPhoto?.d?.detail;
+          if (!l) return; // Shouldn't happen
           const ai = l.indexOf(this.touchAnchor);
           const oi = l.indexOf(overPhoto);
           if (ai === -1 || oi === -1) return; // Shouldn't happen
@@ -474,14 +499,16 @@ export default defineComponent({
 
         // Walk over rows
         let i = rowIdx;
-        let j = this.rows[i].photos.indexOf(this.touchAnchor);
+        let j = this.rows[i].photos?.indexOf(this.touchAnchor) ?? -2;
+        if (j === -2) return; // row is not initialized yet?!
         while (true) {
           if (j < 0) {
             while (i > 0 && !this.rows[--i].photos);
-            if (!this.rows[i].photos) break;
-            j = this.rows[i].photos.length - 1;
+            const plen = this.rows[i].photos?.length;
+            if (!plen) break;
+            j = plen - 1;
             continue;
-          } else if (j >= this.rows[i].photos.length) {
+          } else if (j >= this.rows[i].photos!.length) {
             while (i < this.rows.length - 1 && !this.rows[++i].photos);
             if (!this.rows[i].photos) break;
             j = 0;
@@ -549,7 +576,7 @@ export default defineComponent({
       }
 
       if (!noUpdate) {
-        this.updateHeadSelected(this.heads[photo.d.dayid]);
+        this.updateHeadSelected(this.heads[photo.dayid]);
         this.$forceUpdate();
       }
     },
@@ -557,11 +584,11 @@ export default defineComponent({
     /** Multi-select */
     selectMulti(photo: IPhoto, rows: IRow[], rowIdx: number) {
       const pRow = rows[rowIdx];
-      const pIdx = pRow.photos.indexOf(photo);
+      const pIdx = pRow.photos?.indexOf(photo) ?? -1;
       if (pIdx === -1) return;
 
       const updateDaySet = new Set<number>();
-      let behind = [];
+      let behind: IPhoto[] = [];
       let behindFound = false;
 
       // Look behind
@@ -570,16 +597,16 @@ export default defineComponent({
         if (rows[i].type !== IRowType.PHOTOS) continue;
         if (!rows[i].photos?.length) break;
 
-        const sj = i === rowIdx ? pIdx : rows[i].photos.length - 1;
+        const sj = i === rowIdx ? pIdx : rows[i].photos!.length - 1;
         for (let j = sj; j >= 0; j--) {
-          const p = rows[i].photos[j];
+          const p = rows[i].photos![j];
           if (p.flag & this.c.FLAG_PLACEHOLDER || !p.fileid) continue;
           if (p.flag & this.c.FLAG_SELECTED) {
             behindFound = true;
             break;
           }
           behind.push(p);
-          updateDaySet.add(p.d.dayid);
+          updateDaySet.add(p.dayid);
         }
 
         if (behindFound) break;
@@ -587,23 +614,25 @@ export default defineComponent({
 
       // Select everything behind
       if (behindFound) {
+        const detail = photo.d!.detail!;
+
         // Clear everything in front in this day
-        const pdIdx = photo.d.detail.indexOf(photo);
-        for (let i = pdIdx + 1; i < photo.d.detail.length; i++) {
-          const p = photo.d.detail[i];
-          if (p.flag & this.c.FLAG_SELECTED) this.selectPhoto(p, false, true);
+        const pdIdx = detail.indexOf(photo);
+        for (let i = pdIdx + 1; i < detail.length; i++) {
+          if (detail[i].flag & this.c.FLAG_SELECTED)
+            this.selectPhoto(detail[i], false, true);
         }
 
         // Clear everything else in front
         Array.from(this.selection.values())
           .filter((p: IPhoto) => {
             return this.isreverse
-              ? p.d.dayid > photo.d.dayid
-              : p.d.dayid < photo.d.dayid;
+              ? p.dayid > photo.dayid
+              : p.dayid < photo.dayid;
           })
           .forEach((photo: IPhoto) => {
             this.selectPhoto(photo, false, true);
-            updateDaySet.add(photo.d.dayid);
+            updateDaySet.add(photo.dayid);
           });
 
         behind.forEach((p) => this.selectPhoto(p, true, true));
@@ -615,8 +644,8 @@ export default defineComponent({
     /** Select or deselect all photos in a head */
     selectHead(head: IHeadRow) {
       head.selected = !head.selected;
-      for (const row of head.day.rows) {
-        for (const photo of row.photos) {
+      for (const row of head.day.rows ?? []) {
+        for (const photo of row.photos ?? []) {
           this.selectPhoto(photo, head.selected, true);
         }
       }
@@ -628,8 +657,8 @@ export default defineComponent({
       let selected = true;
 
       // Check if all photos are selected
-      for (const row of head.day.rows) {
-        for (const photo of row.photos) {
+      for (const row of head.day.rows ?? []) {
+        for (const photo of row.photos ?? []) {
           if (!(photo.flag & this.c.FLAG_SELECTED)) {
             selected = false;
             break;
@@ -647,7 +676,7 @@ export default defineComponent({
       const toClear = only || this.selection.values();
       Array.from(toClear).forEach((photo: IPhoto) => {
         photo.flag &= ~this.c.FLAG_SELECTED;
-        heads.add(this.heads[photo.d.dayid]);
+        heads.add(this.heads[photo.dayid]);
         this.selection.delete(photo.fileid);
         this.selectionChanged();
       });
@@ -663,7 +692,7 @@ export default defineComponent({
 
       // FileID => Photo for new day
       const dayMap = new Map<number, IPhoto>();
-      day.detail.forEach((photo) => {
+      day.detail?.forEach((photo) => {
         dayMap.set(photo.fileid, photo);
       });
 
@@ -674,13 +703,13 @@ export default defineComponent({
         }
 
         // Remove all selections that are not in the new day
-        if (!dayMap.has(fileid)) {
+        const newPhoto = dayMap.get(fileid);
+        if (!newPhoto) {
           this.selection.delete(fileid);
           return;
         }
 
         // Update the photo object
-        const newPhoto = dayMap.get(fileid);
         this.selection.set(fileid, newPhoto);
         newPhoto.flag |= this.c.FLAG_SELECTED;
       });
@@ -749,10 +778,7 @@ export default defineComponent({
       for await (const delIds of dav.deletePhotos(
         Array.from(selection.values())
       )) {
-        const delPhotos = delIds
-          .filter((id) => id)
-          .map((id) => selection.get(id));
-        this.deletePhotos(delPhotos);
+        this.deleteSelectedPhotosById(delIds, selection);
       }
     },
 
@@ -793,12 +819,7 @@ export default defineComponent({
         Array.from(selection.keys()),
         !this.routeIsArchive()
       )) {
-        delIds = delIds.filter((x) => x);
-        if (delIds.length === 0) {
-          continue;
-        }
-        const delPhotos = delIds.map((id) => selection.get(id));
-        this.deletePhotos(delPhotos);
+        this.deleteSelectedPhotosById(delIds, selection);
       }
     },
 
@@ -858,10 +879,7 @@ export default defineComponent({
         <string>name,
         Array.from(selection.values())
       )) {
-        const delPhotos = delIds
-          .filter((x) => x)
-          .map((id) => selection.get(id));
-        this.deletePhotos(delPhotos);
+        this.deleteSelectedPhotosById(delIds, selection);
       }
     },
 
diff --git a/src/components/Sidebar.vue b/src/components/Sidebar.vue
index df775145..f576cc6c 100644
--- a/src/components/Sidebar.vue
+++ b/src/components/Sidebar.vue
@@ -110,7 +110,7 @@ export default defineComponent({
     },
 
     handleClose() {
-      emit("memories:sidebar:closed", null);
+      emit("memories:sidebar:closed", {});
     },
 
     handleOpen() {
@@ -120,7 +120,7 @@ export default defineComponent({
         if (e.key.length === 1) e.stopPropagation();
       });
 
-      emit("memories:sidebar:opened", null);
+      emit("memories:sidebar:opened", {});
     },
 
     handleNativeOpen() {
diff --git a/src/components/SplitTimeline.vue b/src/components/SplitTimeline.vue
index 4fe0bbba..c7aa824b 100644
--- a/src/components/SplitTimeline.vue
+++ b/src/components/SplitTimeline.vue
@@ -46,7 +46,7 @@ export default defineComponent({
     primaryPos: 0,
     containerSize: 0,
     mobileOpen: 1,
-    hammer: null as HammerManager,
+    hammer: null as HammerManager | null,
     photoCount: 0,
   }),
 
@@ -85,7 +85,7 @@ export default defineComponent({
 
   beforeDestroy() {
     this.pointerUp();
-    this.hammer.destroy();
+    this.hammer?.destroy();
   },
 
   methods: {
@@ -133,7 +133,7 @@ export default defineComponent({
       this.pointerDown = false;
       document.removeEventListener("pointermove", this.documentPointerMove);
       document.removeEventListener("pointerup", this.pointerUp);
-      emit("memories:window:resize", null);
+      emit("memories:window:resize", {});
     },
 
     setFlexBasis(pos: { clientX: number; clientY: number }) {
@@ -154,7 +154,7 @@ export default defineComponent({
       // so that we can prepare in advance for showing more photos
       // on the timeline
       await this.$nextTick();
-      emit("memories:window:resize", null);
+      emit("memories:window:resize", {});
     },
 
     async mobileSwipeDown() {
@@ -165,7 +165,7 @@ export default defineComponent({
       // ends. Note that this is necesary: the height of the timeline inner
       // div is also animated to the smaller size.
       await new Promise((resolve) => setTimeout(resolve, 300));
-      emit("memories:window:resize", null);
+      emit("memories:window:resize", {});
     },
   },
 });
diff --git a/src/components/Timeline.vue b/src/components/Timeline.vue
index 1e1271b2..b76a145a 100644
--- a/src/components/Timeline.vue
+++ b/src/components/Timeline.vue
@@ -88,7 +88,7 @@
       :heads="heads"
       :rows="list"
       :isreverse="isMonthView"
-      :recycler="$refs.recycler"
+      :recycler="$refs.recycler?.$el"
       @refresh="softRefresh"
       @delete="deleteFromViewWithAnimation"
       @updateLoading="updateLoading"
@@ -374,8 +374,8 @@ export default defineComponent({
       this.loadedDays.clear();
       this.sizedDays.clear();
       this.fetchDayQueue = [];
-      window.clearTimeout(this.fetchDayTimer);
-      window.clearTimeout(this.resizeTimer);
+      window.clearTimeout(this.fetchDayTimer ?? 0);
+      window.clearTimeout(this.resizeTimer ?? 0);
     },
 
     /** Recreate everything */
@@ -492,7 +492,7 @@ export default defineComponent({
         }
 
         // Initialize photos and add placeholders
-        if (row.pct && !row.photos.length) {
+        if (row.pct && !row.photos?.length) {
           row.photos = new Array(row.pct);
           for (let j = 0; j < row.pct; j++) {
             // Any row that has placeholders has ONLY placeholders
@@ -500,6 +500,7 @@ export default defineComponent({
             row.photos[j] = {
               flag: this.c.FLAG_PLACEHOLDER,
               fileid: Math.random(),
+              dayid: row.dayId,
               dispW: utils.roundHalf(this.rowWidth / this.numCols),
               dispX: utils.roundHalf((j * this.rowWidth) / this.numCols),
               dispH: this.rowHeight,
@@ -568,7 +569,7 @@ export default defineComponent({
         if (this.loadedDays.has(item.dayId)) {
           if (!this.sizedDays.has(item.dayId)) {
             // Just quietly reflow without refetching
-            this.processDay(item.dayId, item.day.detail);
+            this.processDay(item.dayId, item.day.detail!);
           }
           continue;
         }
@@ -692,7 +693,7 @@ export default defineComponent({
       // Filter out hidden folders
       if (!this.config_showHidden) {
         this.folders = this.folders.filter(
-          (f) => !f.name.startsWith(".") && f.previews.length
+          (f) => !f.name.startsWith(".") && f.previews?.length
         );
       }
     },
@@ -716,7 +717,7 @@ export default defineComponent({
       const cacheUrl = <string>this.$route.name + url;
 
       // Try cache first
-      let cache: IDay[];
+      let cache: IDay[] | null = null;
 
       // Make sure to refresh scroll later
       this.currentEnd = -1;
@@ -730,18 +731,19 @@ export default defineComponent({
           data = await dav.getOnThisDayData();
         } else if (dav.isSingleItem()) {
           data = await dav.getSingleItemData();
-          this.$router.replace(utils.getViewerRoute(data[0]!.detail[0]));
+          this.$router.replace(utils.getViewerRoute(data[0]!.detail![0]));
         } else {
           // Try the cache
-          try {
-            cache = noCache ? null : await utils.getCachedData(cacheUrl);
-            if (cache) {
-              await this.processDays(cache);
-              this.loading--;
+          if (!noCache) {
+            try {
+              if ((cache = await utils.getCachedData(cacheUrl))) {
+                await this.processDays(cache);
+                this.loading--;
+              }
+            } catch {
+              console.warn(`Failed to process days cache: ${cacheUrl}`);
+              cache = null;
             }
-          } catch {
-            console.warn(`Failed to process days cache: ${cacheUrl}`);
-            cache = null;
           }
 
           // Get from network
@@ -760,6 +762,7 @@ export default defineComponent({
         console.error(err);
         showError(err?.response?.data?.message || err.message);
       } finally {
+        // If cache is set here, loading was already decremented
         if (!cache) this.loading--;
       }
     },
@@ -891,7 +894,8 @@ export default defineComponent({
       // Look for cache
       const cacheUrl = this.getDayUrl(dayId);
       try {
-        this.processDay(dayId, await utils.getCachedData(cacheUrl));
+        const cache = await utils.getCachedData<IPhoto[]>(cacheUrl);
+        if (cache) this.processDay(dayId, cache);
       } catch {
         console.warn(`Failed to process day cache: ${cacheUrl}`);
       }
@@ -936,8 +940,8 @@ export default defineComponent({
         // It is already sorted in dayid DESC
         const dayMap = new Map<number, IPhoto[]>();
         for (const photo of data) {
-          if (!dayMap.get(photo.dayid)) dayMap.set(photo.dayid, []);
-          dayMap.get(photo.dayid).push(photo);
+          if (!dayMap.has(photo.dayid)) dayMap.set(photo.dayid, []);
+          dayMap.get(photo.dayid)!.push(photo);
         }
 
         // Store cache asynchronously
@@ -997,9 +1001,10 @@ export default defineComponent({
       // Set and make reactive
       day.count = data.length;
       day.detail = data;
+      day.rows ??= [];
 
       // Reset rows including placeholders
-      for (const row of head.day.rows || []) {
+      for (const row of day.rows) {
         row.photos = [];
       }
 
@@ -1136,8 +1141,8 @@ export default defineComponent({
         // These may be valid, e.g. in face rects. All we need to have
         // is a unique Vue key for the v-for loop.
         const key = photo.faceid || photo.fileid;
-        if (seen.has(key)) {
-          const val = seen.get(key);
+        const val = seen.get(key);
+        if (val) {
           photo.key = `${key}-${val}`;
           seen.set(key, val + 1);
         } else {
@@ -1146,7 +1151,7 @@ export default defineComponent({
         }
 
         // Add photo to row
-        row.photos.push(photo);
+        row.photos!.push(photo);
         delete row.pct;
       }
 
@@ -1187,8 +1192,8 @@ export default defineComponent({
         needAdjust = true;
 
         // Remove from day
-        const idx = head.day.rows.indexOf(row);
-        if (idx >= 0) head.day.rows.splice(idx, 1);
+        const idx = day.rows.indexOf(row);
+        if (idx >= 0) day.rows.splice(idx, 1);
       }
 
       // This will be true even if the head is being spliced
@@ -1210,6 +1215,9 @@ export default defineComponent({
 
     /** Add and get a new blank photos row */
     addRow(day: IDay): IRow {
+      // Make sure rows exists
+      day.rows ??= [];
+
       // Create new row
       const row = {
         id: `${day.dayid}-${day.rows.length}`,
@@ -1242,7 +1250,7 @@ export default defineComponent({
       if (delPhotos.length === 0) return;
 
       // Get all days that need to be updatd
-      const updatedDays = new Set<IDay>(delPhotos.map((p) => p.d));
+      const updatedDays = new Set<IDay>(delPhotos.map((p) => p.d!));
       const delPhotosSet = new Set(delPhotos);
 
       // Animate the deletion
@@ -1258,8 +1266,8 @@ export default defineComponent({
 
       // Reflow all touched days
       for (const day of updatedDays) {
-        const newDetail = day.detail.filter((p) => !delPhotosSet.has(p));
-        this.processDay(day.dayid, newDetail);
+        const newDetail = day.detail?.filter((p) => !delPhotosSet.has(p));
+        this.processDay(day.dayid, newDetail!);
       }
     },
   },
diff --git a/src/components/frame/Cluster.vue b/src/components/frame/Cluster.vue
index f86a2a49..de1989d2 100644
--- a/src/components/frame/Cluster.vue
+++ b/src/components/frame/Cluster.vue
@@ -36,7 +36,7 @@ import { defineComponent, PropType } from "vue";
 import { getCurrentUser } from "@nextcloud/auth";
 import NcCounterBubble from "@nextcloud/vue/dist/Components/NcCounterBubble";
 
-import { IAlbum, ICluster, IFace } from "../../types";
+import type { IAlbum, ICluster, IFace, IPhoto } from "../../types";
 import { getPreviewUrl } from "../../services/utils/helpers";
 import errorsvg from "../../assets/error.svg";
 
@@ -66,7 +66,11 @@ export default defineComponent({
       if (this.error) return errorsvg;
 
       if (this.album) {
-        const mock = { fileid: this.album.last_added_photo, etag: "", flag: 0 };
+        const mock = {
+          fileid: this.album.last_added_photo,
+          etag: this.album.album_id,
+          flag: 0,
+        } as unknown as IPhoto;
         return getPreviewUrl(mock, true, 512);
       }
 
diff --git a/src/components/frame/Folder.vue b/src/components/frame/Folder.vue
index ad4d9ba4..c4bba0f6 100644
--- a/src/components/frame/Folder.vue
+++ b/src/components/frame/Folder.vue
@@ -46,7 +46,10 @@ export default defineComponent({
   mixins: [UserConfig],
 
   props: {
-    data: Object as PropType<IFolder>,
+    data: {
+      type: Object as PropType<IFolder>,
+      required: true,
+    },
   },
 
   data: () => ({
diff --git a/src/components/frame/Photo.vue b/src/components/frame/Photo.vue
index 1bcb44bb..1c50847b 100644
--- a/src/components/frame/Photo.vue
+++ b/src/components/frame/Photo.vue
@@ -99,7 +99,7 @@ export default defineComponent({
 
   data: () => ({
     touchTimer: 0,
-    faceSrc: null,
+    faceSrc: null as string | null,
   }),
 
   watch: {
@@ -144,6 +144,7 @@ export default defineComponent({
       if (this.data.liveid) {
         return utils.getLivePhotoVideoUrl(this.data, true);
       }
+      return null;
     },
 
     src(): string | null {
@@ -171,7 +172,7 @@ export default defineComponent({
       let base = 256;
 
       // Check if displayed size is larger than the image
-      if (this.data.dispH > base * 0.9 && this.data.dispW > base * 0.9) {
+      if (this.data.dispH! > base * 0.9 && this.data.dispW! > base * 0.9) {
         // Get a bigger image
         // 1. No trickery here, just get one size bigger. This is to
         //    ensure that the images can be cached even after reflow.
@@ -208,6 +209,7 @@ export default defineComponent({
 
       const canvas = document.createElement("canvas");
       const context = canvas.getContext("2d");
+      if (!context) return; // failed to create canvas
 
       canvas.width = img.naturalWidth;
       canvas.height = img.naturalHeight;
@@ -223,6 +225,7 @@ export default defineComponent({
 
       canvas.toBlob(
         (blob) => {
+          if (!blob) return;
           this.faceSrc = URL.createObjectURL(blob);
         },
         "image/jpeg",
diff --git a/src/components/frame/XImgCache.ts b/src/components/frame/XImgCache.ts
index e7f1877b..4f05b090 100644
--- a/src/components/frame/XImgCache.ts
+++ b/src/components/frame/XImgCache.ts
@@ -49,7 +49,7 @@ document.addEventListener("DOMContentLoaded", () => {
 /** Change stickiness for a BLOB url */
 export async function sticky(url: string, delta: number) {
   if (!BLOB_STICKY.has(url)) BLOB_STICKY.set(url, 0);
-  const val = BLOB_STICKY.get(url) + delta;
+  const val = BLOB_STICKY.get(url)! + delta;
   if (val <= 0) {
     BLOB_STICKY.delete(url);
   } else {
@@ -62,15 +62,16 @@ export async function fetchImage(url: string) {
   startWorker();
 
   // Check memcache entry
-  if (BLOB_CACHE.has(url)) return BLOB_CACHE.get(url)[1];
+  let entry = BLOB_CACHE.get(url);
+  if (entry) return entry[1];
 
   // Fetch image
   const blobUrl = await importer<typeof w.fetchImageSrc>("fetchImageSrc")(url);
 
   // Check memcache entry again and revoke if it was added in the meantime
-  if (BLOB_CACHE.has(url)) {
+  if ((entry = BLOB_CACHE.get(url))) {
     URL.revokeObjectURL(blobUrl);
-    return BLOB_CACHE.get(url)[1];
+    return entry[1];
   }
 
   // Create new memecache entry
diff --git a/src/components/frame/XImgWorker.ts b/src/components/frame/XImgWorker.ts
index 010905e1..69b3d269 100644
--- a/src/components/frame/XImgWorker.ts
+++ b/src/components/frame/XImgWorker.ts
@@ -1,19 +1,19 @@
 import { CacheExpiration } from "workbox-expiration";
 import { workerExport } from "../../worker";
 
-type BlobCallback = {
+interface BlobCallback {
   resolve: (blob: Blob) => void;
   reject: (err: Error) => void;
-};
+}
 
 // Queue of requests to fetch preview images
-type FetchPreviewObject = {
+interface FetchPreviewObject {
   origUrl: string;
   url: URL;
   fileid: number;
   reqid: number;
   done?: boolean;
-};
+}
 let fetchPreviewQueue: FetchPreviewObject[] = [];
 
 // Pending requests
@@ -22,9 +22,12 @@ const pendingUrls = new Map<string, BlobCallback[]>();
 // Cache for preview images
 const cacheName = "images";
 let imageCache: Cache;
-(async () => {
-  imageCache = await caches.open(cacheName);
-})();
+caches
+  .open(cacheName)
+  .then((c) => (imageCache = c))
+  .catch(() => {
+    /* ignore */
+  });
 
 // Expiration for cache
 const expirationManager = new CacheExpiration(cacheName, {
@@ -60,7 +63,9 @@ async function flushPreviewQueue() {
     // it came from a multipreview, so that we can try fetching
     // the single image instead
     const blob = await res.blob();
-    pendingUrls.get(url)?.forEach((cb) => cb?.resolve?.(blob));
+    pendingUrls.get(url)?.forEach((cb) => {
+      cb?.resolve?.(blob);
+    });
     pendingUrls.delete(url);
 
     // Cache response
@@ -68,15 +73,17 @@ async function flushPreviewQueue() {
   };
 
   // Throw error on URL
-  const reject = (url: string, e: any) => {
-    pendingUrls.get(url)?.forEach((cb) => cb?.reject?.(e));
+  const reject = (url: string, e: any): void => {
+    pendingUrls.get(url)?.forEach((cb) => {
+      cb?.reject?.(e);
+    });
     pendingUrls.delete(url);
   };
 
   // Make a single-file request
   const fetchOneSafe = async (p: FetchPreviewObject) => {
     try {
-      resolve(p.origUrl, await fetchOneImage(p.origUrl));
+      await resolve(p.origUrl, await fetchOneImage(p.origUrl));
     } catch (e) {
       reject(p.origUrl, e);
     }
@@ -84,7 +91,8 @@ async function flushPreviewQueue() {
 
   // Check if only one request, not worth a multipreview
   if (fetchPreviewQueueCopy.length === 1) {
-    return fetchOneSafe(fetchPreviewQueueCopy[0]);
+    await fetchOneSafe(fetchPreviewQueueCopy[0]);
+    return;
   }
 
   // Create aggregated request body
@@ -99,7 +107,8 @@ async function flushPreviewQueue() {
   try {
     // Fetch multipreview
     const res = await fetchMultipreview(files);
-    if (res.status !== 200) throw new Error("Error fetching multi-preview");
+    if (res.status !== 200 || !res.body)
+      throw new Error("Error fetching multi-preview");
 
     // Create fake headers for 7-day expiry
     const headers = {
@@ -119,7 +128,7 @@ async function flushPreviewQueue() {
       reqid: number;
       len: number;
       type: string;
-    } = null;
+    } | null = null;
 
     // Index at which we are currently reading
     let idx = 0;
@@ -161,30 +170,31 @@ async function flushPreviewQueue() {
           if (bufSize - jsonStart < jsonLen) break;
           const jsonB = buffer.slice(jsonStart, jsonStart + jsonLen);
           const jsonT = new TextDecoder().decode(jsonB);
-          params = JSON.parse(jsonT);
           idx = jsonStart + jsonLen;
+          params = JSON.parse(jsonT);
+          params = params!;
         }
 
         // Read the image data
-        if (bufSize - idx < params.len) break;
-        const imgBlob = new Blob([buffer.slice(idx, idx + params.len)], {
-          type: params.type,
+        if (bufSize - idx < params!.len) break;
+        const imgBlob = new Blob([buffer.slice(idx, idx + params!.len)], {
+          type: params!.type,
         });
-        idx += params.len;
+        idx += params!.len;
 
         // Initiate callbacks
-        fetchPreviewQueueCopy
-          .filter((p) => p.reqid === params.reqid && !p.done)
-          .forEach((p) => {
+        for (const p of fetchPreviewQueueCopy) {
+          if (p.reqid === params.reqid && !p.done) {
             try {
-              const dummy = getResponse(imgBlob, params.type, headers);
-              resolve(p.origUrl, dummy);
+              const dummy = getResponse(imgBlob, params!.type, headers);
+              await resolve(p.origUrl, dummy);
               p.done = true;
             } catch (e) {
               // In case of error, we want to try fetching the single
               // image instead, so we don't reject here
             }
-          });
+          }
+        }
 
         // Reset for next iteration
         params = null;
@@ -272,7 +282,7 @@ function getResponse(blob: Blob, type: string | null, headers: any = {}) {
       "Content-Type": type || headers["content-type"],
       "Content-Length": blob.size.toString(),
       "Cache-Control": headers["cache-control"],
-      Expires: headers["expires"],
+      Expires: headers.expires,
     },
   });
 }
diff --git a/src/components/frame/XImgWorkerStub.ts b/src/components/frame/XImgWorkerStub.ts
index c3162f8b..26f76cad 100644
--- a/src/components/frame/XImgWorkerStub.ts
+++ b/src/components/frame/XImgWorkerStub.ts
@@ -9,11 +9,11 @@
 const pathname = self.location.pathname;
 __webpack_public_path__ = pathname.substring(0, pathname.lastIndexOf("/") + 1);
 
-const missedQueue = [];
+const missedQueue: any[] = [];
 self.onmessage = function (val: any) {
   missedQueue.push(val);
 };
 
 import("./XImgWorker").then(function () {
-  missedQueue.forEach((data: any) => self.onmessage(data));
+  missedQueue.forEach((data: any) => self.onmessage?.(data));
 });
diff --git a/src/components/modal/AlbumCollaborators.vue b/src/components/modal/AlbumCollaborators.vue
index 9a548ee2..f5030f0d 100644
--- a/src/components/modal/AlbumCollaborators.vue
+++ b/src/components/modal/AlbumCollaborators.vue
@@ -210,7 +210,7 @@ export default defineComponent({
     selectedCollaboratorsKeys: [] as string[],
     currentSearchResults: [] as Collaborator[],
     loadingAlbum: false,
-    errorFetchingAlbum: null,
+    errorFetchingAlbum: null as number | null,
     loadingCollaborators: false,
     errorFetchingCollaborators: null,
     randomId: Math.random().toString().substring(2, 10),
@@ -370,10 +370,9 @@ export default defineComponent({
         this.loadingAlbum = true;
         this.errorFetchingAlbum = null;
 
-        const album = await dav.getAlbum(
-          getCurrentUser()?.uid.toString(),
-          this.albumName
-        );
+        const uid = getCurrentUser()?.uid.toString();
+        if (!uid) return;
+        const album = await dav.getAlbum(uid, this.albumName);
         this.populateCollaborators(album.collaborators);
       } catch (error) {
         if (error.response?.status === 404) {
@@ -401,10 +400,9 @@ export default defineComponent({
 
     async updateAlbumCollaborators() {
       try {
-        const album = await dav.getAlbum(
-          getCurrentUser()?.uid.toString(),
-          this.albumName
-        );
+        const uid = getCurrentUser()?.uid?.toString();
+        if (!uid) return;
+        const album = await dav.getAlbum(uid, this.albumName);
         await dav.updateAlbum(album, {
           albumName: this.albumName,
           properties: {
diff --git a/src/components/modal/EditDate.vue b/src/components/modal/EditDate.vue
index 0642b08d..a0368981 100644
--- a/src/components/modal/EditDate.vue
+++ b/src/components/modal/EditDate.vue
@@ -176,16 +176,18 @@ export default defineComponent({
     },
 
     dateDiff() {
-      return this.date.getTime() - this.dateLast.getTime();
+      return this.date && this.dateLast
+        ? this.date.getTime() - this.dateLast.getTime()
+        : 0;
     },
 
     origDateNewest() {
-      return new Date(this.sortedPhotos[0].datetaken);
+      return new Date(this.sortedPhotos[0].datetaken!);
     },
 
     origDateOldest() {
       return new Date(
-        this.sortedPhotos[this.sortedPhotos.length - 1].datetaken
+        this.sortedPhotos[this.sortedPhotos.length - 1].datetaken!
       );
     },
 
@@ -212,13 +214,16 @@ export default defineComponent({
 
   methods: {
     init() {
-      const photos = (this.sortedPhotos = [...this.photos] as IPhoto[]);
+      // Filter out only photos that have a datetaken
+      const photos = (this.sortedPhotos = this.photos.filter(
+        (photo) => photo.datetaken !== undefined
+      ));
 
       // Sort photos by datetaken descending
-      photos.sort((a, b) => b.datetaken - a.datetaken);
+      photos.sort((a, b) => b.datetaken! - a.datetaken!);
 
       // Get date of newest photo
-      let date = new Date(photos[0].datetaken);
+      let date = new Date(photos[0].datetaken!);
       this.year = date.getUTCFullYear().toString();
       this.month = (date.getUTCMonth() + 1).toString();
       this.day = date.getUTCDate().toString();
@@ -228,7 +233,7 @@ export default defineComponent({
 
       // Get date of oldest photo
       if (photos.length > 1) {
-        date = new Date(photos[photos.length - 1].datetaken);
+        date = new Date(photos[photos.length - 1].datetaken!);
         this.yearLast = date.getUTCFullYear().toString();
         this.monthLast = (date.getUTCMonth() + 1).toString();
         this.dayLast = date.getUTCDate().toString();
@@ -262,7 +267,7 @@ export default defineComponent({
         return undefined;
       }
 
-      if (this.sortedPhotos.length === 0) {
+      if (this.sortedPhotos.length === 0 || !this.date) {
         return undefined;
       }
 
@@ -278,7 +283,7 @@ export default defineComponent({
     },
 
     newestChange(time = false) {
-      if (this.sortedPhotos.length === 0) {
+      if (this.sortedPhotos.length === 0 || !this.date) {
         return;
       }
 
diff --git a/src/components/modal/EditLocation.vue b/src/components/modal/EditLocation.vue
index 7630d518..1bdbfa1b 100644
--- a/src/components/modal/EditLocation.vue
+++ b/src/components/modal/EditLocation.vue
@@ -203,16 +203,17 @@ export default defineComponent({
     },
 
     result() {
-      if (!this.dirty) {
-        return null;
-      }
+      if (!this.dirty) return null;
+
+      const lat = (this.lat || 0).toFixed(6);
+      const lon = (this.lon || 0).toFixed(6);
 
       return {
-        GPSLatitude: this.lat,
-        GPSLongitude: this.lon,
-        GPSLatitudeRef: this.lat,
-        GPSLongitudeRef: this.lon,
-        GPSCoordinates: `${this.lat.toFixed(6)}, ${this.lon.toFixed(6)}`,
+        GPSLatitude: lat,
+        GPSLongitude: lon,
+        GPSLatitudeRef: lat,
+        GPSLongitudeRef: lon,
+        GPSCoordinates: `${lat}, ${lon}`,
       };
     },
   },
diff --git a/src/components/modal/EditMetadataModal.vue b/src/components/modal/EditMetadataModal.vue
index 28c3f866..137ef17d 100644
--- a/src/components/modal/EditMetadataModal.vue
+++ b/src/components/modal/EditMetadataModal.vue
@@ -92,7 +92,7 @@ export default defineComponent({
   mixins: [UserConfig],
 
   data: () => ({
-    photos: null as IPhoto[],
+    photos: null as IPhoto[] | null,
     sections: [] as number[],
     show: false,
     processing: false,
@@ -183,7 +183,7 @@ export default defineComponent({
       this.processing = true;
 
       // Update exif fields
-      const calls = this.photos.map((p) => async () => {
+      const calls = this.photos!.map((p) => async () => {
         try {
           let dirty = false;
           const fileid = p.fileid;
@@ -223,7 +223,7 @@ export default defineComponent({
           }
         } finally {
           done++;
-          this.progress = Math.round((done * 100) / this.photos.length);
+          this.progress = Math.round((done * 100) / this.photos!.length);
         }
       });
 
diff --git a/src/components/modal/EditTags.vue b/src/components/modal/EditTags.vue
index eb775012..c7d70bd4 100644
--- a/src/components/modal/EditTags.vue
+++ b/src/components/modal/EditTags.vue
@@ -40,7 +40,7 @@ export default defineComponent({
 
   methods: {
     init() {
-      let tagIds: number[] = null;
+      let tagIds: number[] | null = null;
 
       // Find common tags in all selected photos
       for (const photo of this.photos) {
@@ -53,7 +53,7 @@ export default defineComponent({
         tagIds = tagIds ? [...tagIds].filter((x) => s.has(x)) : [...s];
       }
 
-      this.tagSelection = tagIds;
+      this.tagSelection = tagIds || [];
       this.origIds = new Set(this.tagSelection);
     },
 
diff --git a/src/components/modal/FaceDeleteModal.vue b/src/components/modal/FaceDeleteModal.vue
index 4742411c..bc439bfd 100644
--- a/src/components/modal/FaceDeleteModal.vue
+++ b/src/components/modal/FaceDeleteModal.vue
@@ -83,7 +83,7 @@ export default defineComponent({
         } else {
           await dav.setVisibilityPeopleFaceRecognition(this.name, false);
         }
-        this.$router.push({ name: this.$route.name });
+        this.$router.push({ name: this.$route.name as string });
         this.close();
       } catch (error) {
         console.log(error);
@@ -96,4 +96,4 @@ export default defineComponent({
     },
   },
 });
-</script>
\ No newline at end of file
+</script>
diff --git a/src/components/modal/FaceEditModal.vue b/src/components/modal/FaceEditModal.vue
index aaddbe4b..6d6fe225 100644
--- a/src/components/modal/FaceEditModal.vue
+++ b/src/components/modal/FaceEditModal.vue
@@ -97,7 +97,7 @@ export default defineComponent({
           await dav.renamePeopleFaceRecognition(this.oldName, this.name);
         }
         this.$router.push({
-          name: this.$route.name,
+          name: this.$route.name as string,
           params: { user: this.user, name: this.name },
         });
         this.close();
diff --git a/src/components/modal/FaceList.vue b/src/components/modal/FaceList.vue
index 1068e568..0d27172d 100644
--- a/src/components/modal/FaceList.vue
+++ b/src/components/modal/FaceList.vue
@@ -48,7 +48,7 @@ export default defineComponent({
     user: "",
     name: "",
     list: null as ICluster[] | null,
-    fuse: null as Fuse<ICluster>,
+    fuse: null as Fuse<ICluster> | null,
     search: "",
   }),
 
diff --git a/src/components/modal/FaceMoveModal.vue b/src/components/modal/FaceMoveModal.vue
index 795868ae..495bb84e 100644
--- a/src/components/modal/FaceMoveModal.vue
+++ b/src/components/modal/FaceMoveModal.vue
@@ -130,7 +130,8 @@ export default defineComponent({
           }
         });
         for await (const resp of dav.runInParallel(calls, 10)) {
-          this.moved(resp);
+          const valid = resp.filter((r): r is IPhoto => r !== undefined);
+          this.moved(valid);
         }
       } catch (error) {
         console.error(error);
diff --git a/src/components/modal/Modal.vue b/src/components/modal/Modal.vue
index aa5015c0..48f929e4 100644
--- a/src/components/modal/Modal.vue
+++ b/src/components/modal/Modal.vue
@@ -46,8 +46,8 @@ export default defineComponent({
   data: () => ({
     isSidebarShown: false,
     sidebarWidth: 400,
-    trapElements: [],
-    _mutationObserver: null,
+    trapElements: [] as HTMLElement[],
+    _mutationObserver: null! as MutationObserver,
   }),
 
   beforeMount() {
@@ -87,7 +87,8 @@ export default defineComponent({
      * That way we can adjust the focusTrap
      */
     handleBodyMutation(mutations: MutationRecord[]) {
-      const test = (node: HTMLElement) =>
+      const test = (node: Node): node is HTMLElement =>
+        node instanceof HTMLElement &&
         node?.classList?.contains("v-popper__popper");
 
       mutations.forEach((mutation) => {
diff --git a/src/components/modal/NodeShareModal.vue b/src/components/modal/NodeShareModal.vue
index ec34894a..a8f33b2a 100644
--- a/src/components/modal/NodeShareModal.vue
+++ b/src/components/modal/NodeShareModal.vue
@@ -189,7 +189,7 @@ export default defineComponent({
     },
 
     getShareLabels(share: IShare): string {
-      const labels = [];
+      const labels: string[] = [];
       if (share.hasPassword) {
         labels.push(this.t("memories", "Password protected"));
       }
diff --git a/src/components/modal/ShareModal.vue b/src/components/modal/ShareModal.vue
index 11a82f47..4a429803 100644
--- a/src/components/modal/ShareModal.vue
+++ b/src/components/modal/ShareModal.vue
@@ -112,7 +112,7 @@ export default defineComponent({
 
   data: () => {
     return {
-      photo: null as IPhoto,
+      photo: null as IPhoto | null,
       loading: 0,
     };
   },
@@ -127,7 +127,7 @@ export default defineComponent({
     isVideo() {
       return (
         this.photo &&
-        (this.photo.mimetype.startsWith("video/") ||
+        (this.photo.mimetype?.startsWith("video/") ||
           this.photo.flag & this.c.FLAG_IS_VIDEO)
       );
     },
@@ -160,32 +160,32 @@ export default defineComponent({
     },
 
     async sharePreview() {
-      const src = utils.getPreviewUrl(this.photo, false, 2048);
+      const src = utils.getPreviewUrl(this.photo!, false, 2048);
       this.shareWithHref(src, true);
     },
 
     async shareHighRes() {
-      const fileid = this.photo.fileid;
+      const fileid = this.photo!.fileid;
       const src = this.isVideo
         ? API.VIDEO_TRANSCODE(fileid, "max.mov")
-        : API.IMAGE_DECODABLE(fileid, this.photo.etag);
+        : API.IMAGE_DECODABLE(fileid, this.photo!.etag);
       this.shareWithHref(src, !this.isVideo);
     },
 
     async shareOriginal() {
-      this.shareWithHref(dav.getDownloadLink(this.photo));
+      this.shareWithHref(dav.getDownloadLink(this.photo!));
     },
 
     async shareLink() {
       this.l(async () => {
-        const fileInfo = (await dav.getFiles([this.photo]))[0];
+        const fileInfo = (await dav.getFiles([this.photo!]))[0];
         globalThis.shareNodeLink(fileInfo.filename, true);
       });
       this.close();
     },
 
     async shareWithHref(href: string, replaceExt = false) {
-      let blob: Blob;
+      let blob: Blob | undefined;
       await this.l(async () => {
         const res = await axios.get(href, { responseType: "blob" });
         blob = res.data;
@@ -196,11 +196,11 @@ export default defineComponent({
         return;
       }
 
-      let basename = this.photo.basename;
+      let basename = this.photo?.basename ?? "blank";
 
       if (replaceExt) {
         // Fix basename extension
-        let targetExts = [];
+        let targetExts: string[] = [];
         if (blob.type === "image/png") {
           targetExts = ["png"];
         } else {
@@ -208,7 +208,8 @@ export default defineComponent({
         }
 
         // Append extension if not found
-        if (!targetExts.includes(basename.split(".").pop().toLowerCase())) {
+        const baseExt = basename.split(".").pop()?.toLowerCase() ?? "";
+        if (!targetExts.includes(baseExt)) {
           basename += "." + targetExts[0];
         }
       }
diff --git a/src/components/top-matter/ClusterTopMatter.vue b/src/components/top-matter/ClusterTopMatter.vue
index 23b30054..a57b47cb 100644
--- a/src/components/top-matter/ClusterTopMatter.vue
+++ b/src/components/top-matter/ClusterTopMatter.vue
@@ -46,7 +46,7 @@ export default defineComponent({
 
   methods: {
     back() {
-      this.$router.push({ name: this.$route.name });
+      this.$router.push({ name: this.$route.name as string });
     },
   },
 });
diff --git a/src/components/top-matter/FaceTopMatter.vue b/src/components/top-matter/FaceTopMatter.vue
index f6410868..b77c3fc3 100644
--- a/src/components/top-matter/FaceTopMatter.vue
+++ b/src/components/top-matter/FaceTopMatter.vue
@@ -13,7 +13,7 @@
       <NcActions :inline="1">
         <NcActionButton
           :aria-label="t('memories', 'Rename person')"
-          @click="$refs.editModal.open()"
+          @click="$refs.editModal?.open()"
           close-after-click
         >
           {{ t("memories", "Rename person") }}
@@ -21,7 +21,7 @@
         </NcActionButton>
         <NcActionButton
           :aria-label="t('memories', 'Merge with different person')"
-          @click="$refs.mergeModal.open()"
+          @click="$refs.mergeModal?.open()"
           close-after-click
         >
           {{ t("memories", "Merge with different person") }}
@@ -36,7 +36,7 @@
         </NcActionCheckbox>
         <NcActionButton
           :aria-label="t('memories', 'Remove person')"
-          @click="$refs.deleteModal.open()"
+          @click="$refs.deleteModal?.open()"
           close-after-click
         >
           {{ t("memories", "Remove person") }}
@@ -104,7 +104,7 @@ export default defineComponent({
     },
 
     back() {
-      this.$router.push({ name: this.$route.name });
+      this.$router.push({ name: this.$route.name as string });
     },
 
     changeShowFaceRect() {
diff --git a/src/components/top-matter/MapSplitMatter.vue b/src/components/top-matter/MapSplitMatter.vue
index 017042bf..bb5b3a13 100644
--- a/src/components/top-matter/MapSplitMatter.vue
+++ b/src/components/top-matter/MapSplitMatter.vue
@@ -65,10 +65,10 @@ const OSM_ATTRIBUTION =
 const CLUSTER_TRANSITION_TIME = 300;
 
 type IMarkerCluster = {
-  id?: number;
+  id: number;
   center: [number, number];
   count: number;
-  preview?: IPhoto;
+  preview: IPhoto;
   dummy?: boolean;
 };
 
diff --git a/src/components/top-matter/OnThisDay.vue b/src/components/top-matter/OnThisDay.vue
index d37cc869..51e14804 100644
--- a/src/components/top-matter/OnThisDay.vue
+++ b/src/components/top-matter/OnThisDay.vue
@@ -82,7 +82,7 @@ export default defineComponent({
     hasRight: false,
     hasLeft: false,
     scrollStack: [] as number[],
-    resizeObserver: null as ResizeObserver,
+    resizeObserver: null! as ResizeObserver,
   }),
 
   mounted() {
@@ -146,7 +146,7 @@ export default defineComponent({
               year,
               text,
               url: "",
-              preview: null,
+              preview: null!,
               photos: [],
             });
             currentText = text;
@@ -167,7 +167,7 @@ export default defineComponent({
       for (const year of this.years) {
         // Try to prioritize landscape photos on desktop
         if (globalThis.windowInnerWidth <= 600) {
-          const landscape = year.photos.filter((p) => p.w > p.h);
+          const landscape = year.photos.filter((p) => (p.w ?? 0) > (p.h ?? 0));
           year.preview = utils.randomChoice(landscape);
         }
 
@@ -214,7 +214,7 @@ export default defineComponent({
 
     click(year: IYear) {
       const allPhotos = this.years.flatMap((y) => y.photos);
-      this.viewer.openStatic(year.preview, allPhotos, 512);
+      this.viewer?.openStatic(year.preview, allPhotos, 512);
     },
   },
 });
diff --git a/src/components/viewer/ImageEditor.vue b/src/components/viewer/ImageEditor.vue
index 23ae89da..c73c6cf2 100644
--- a/src/components/viewer/ImageEditor.vue
+++ b/src/components/viewer/ImageEditor.vue
@@ -45,8 +45,8 @@ export default defineComponent({
   },
 
   data: () => ({
-    exif: null as any,
-    imageEditor: null as FilerobotImageEditor,
+    exif: null as Object | null,
+    imageEditor: null as FilerobotImageEditor | null,
   }),
 
   computed: {
@@ -116,14 +116,14 @@ export default defineComponent({
     },
 
     defaultSavedImageName(): string {
-      return this.photo.basename;
+      return this.photo.basename || "";
     },
 
     defaultSavedImageType(): "jpeg" | "png" | "webp" {
       if (
-        ["image/jpeg", "image/png", "image/webp"].includes(this.photo.mimetype)
+        ["image/jpeg", "image/png", "image/webp"].includes(this.photo.mimetype!)
       ) {
-        return this.photo.mimetype.split("/")[1] as any;
+        return this.photo.mimetype!.split("/")[1] as any;
       }
       return "jpeg";
     },
@@ -169,7 +169,7 @@ export default defineComponent({
   methods: {
     async getImage(): Promise<HTMLImageElement> {
       const img = new Image();
-      img.name = this.photo.basename;
+      img.name = this.defaultSavedImageName;
 
       await new Promise(async (resolve) => {
         img.onload = resolve;
@@ -200,11 +200,11 @@ export default defineComponent({
      */
     async onSave(
       data: {
-        name?: string;
+        name: string;
+        extension: string;
         width?: number;
         height?: number;
         quality?: number;
-        extension?: string;
         fullName?: string;
         imageBase64?: string;
       },
diff --git a/src/components/viewer/PsImage.ts b/src/components/viewer/PsImage.ts
index 68e2311a..04f5f727 100644
--- a/src/components/viewer/PsImage.ts
+++ b/src/components/viewer/PsImage.ts
@@ -79,8 +79,8 @@ export default class ImageContentSetup {
 
   slideActivate() {
     const slide = this.lightbox.currSlide;
-    if (slide.data.highSrcCond === "always") {
-      this.loadFullImage(slide);
+    if (slide?.data.highSrcCond === "always") {
+      this.loadFullImage(slide as PsSlide);
     }
   }
 
@@ -97,7 +97,7 @@ export default class ImageContentSetup {
     img.classList.add("ximg--full");
 
     this.loading++;
-    this.lightbox.ui.updatePreloaderVisibility();
+    this.lightbox.ui?.updatePreloaderVisibility();
 
     fetchImage(slide.data.highSrc)
       .then((blobSrc) => {
@@ -112,7 +112,7 @@ export default class ImageContentSetup {
       })
       .finally(() => {
         this.loading--;
-        this.lightbox.ui.updatePreloaderVisibility();
+        this.lightbox.ui?.updatePreloaderVisibility();
       });
   }
 }
diff --git a/src/components/viewer/PsVideo.ts b/src/components/viewer/PsVideo.ts
index 51d8fcc3..b8c0e5a0 100644
--- a/src/components/viewer/PsVideo.ts
+++ b/src/components/viewer/PsVideo.ts
@@ -6,17 +6,19 @@ import { getCurrentUser } from "@nextcloud/auth";
 import axios from "@nextcloud/axios";
 
 import { API } from "../../services/API";
-import { PsContent, PsEvent, PsSlide } from "./types";
+import type { PsContent, PsEvent } from "./types";
 
 import Player from "video.js/dist/types/player";
 import { QualityLevelList } from "videojs-contrib-quality-levels";
 
 type VideoContent = PsContent & {
-  videoElement: HTMLVideoElement;
-  videojs: Player & {
-    qualityLevels?: () => QualityLevelList;
-  };
-  plyr: globalThis.Plyr;
+  videoElement: HTMLVideoElement | null;
+  videojs:
+    | (Player & {
+        qualityLevels?: () => QualityLevelList;
+      })
+    | null;
+  plyr: globalThis.Plyr | null;
 };
 
 type PsVideoEvent = PsEvent & {
@@ -32,7 +34,7 @@ const config_video_default_quality = Number(
 /**
  * Check if slide has video content
  */
-export function isVideoContent(content: PsSlide | PsContent): boolean {
+export function isVideoContent(content: any): content is VideoContent {
   return content?.data?.type === "video";
 }
 
@@ -109,12 +111,12 @@ class VideoContentSetup {
     });
 
     pswp.on("close", () => {
-      this.destroyVideo(pswp.currSlide.content as VideoContent);
+      this.destroyVideo(pswp.currSlide?.content as VideoContent);
     });
 
     // Prevent closing when video fullscreen is active
     pswp.on("pointerMove", (e) => {
-      const plyr = (<VideoContent>pswp.currSlide.content)?.plyr;
+      const plyr = (<VideoContent>pswp.currSlide?.content)?.plyr;
       if (plyr?.fullscreen.active) {
         e.preventDefault();
       }
@@ -161,7 +163,7 @@ class VideoContentSetup {
     content.videoElement.setAttribute("playsinline", "");
 
     // Add the video element to the actual container
-    content.element.appendChild(content.videoElement);
+    content.element?.appendChild(content.videoElement);
 
     // Create hls sources if enabled
     const sources: {
@@ -202,7 +204,7 @@ class VideoContentSetup {
     let hlsFailed = false;
 
     vjs.on("error", () => {
-      if (vjs.src(undefined).includes("m3u8")) {
+      if (vjs.src(undefined)?.includes("m3u8")) {
         hlsFailed = true;
         console.warn("PsVideo: HLS stream could not be opened.");
 
@@ -245,7 +247,7 @@ class VideoContentSetup {
       playWithDelay();
     });
 
-    content.videojs.qualityLevels()?.on("addqualitylevel", (e) => {
+    content.videojs.qualityLevels?.()?.on("addqualitylevel", (e) => {
       if (e.qualityLevel?.label?.includes("max.m3u8")) {
         // This is the highest quality level
         // and guaranteed to be the last one
@@ -274,6 +276,7 @@ class VideoContentSetup {
   destroyVideo(content: VideoContent) {
     if (isVideoContent(content)) {
       // Destroy videojs
+      content.videojs?.pause?.();
       content.videojs?.dispose?.();
       content.videojs = null;
 
@@ -283,9 +286,11 @@ class VideoContentSetup {
       content.plyr = null;
 
       // Clear the video element
-      const elem: HTMLDivElement = content.element;
-      while (elem.lastElementChild) {
-        elem.removeChild(elem.lastElementChild);
+      if (content.element instanceof HTMLDivElement) {
+        const elem = content.element;
+        while (elem.lastElementChild) {
+          elem.removeChild(elem.lastElementChild);
+        }
       }
       content.videoElement = null;
 
@@ -301,17 +306,17 @@ class VideoContentSetup {
     if (!content.videoElement) return;
 
     // Retain original parent for video element
-    const origParent = content.videoElement.parentElement;
+    const origParent = content.videoElement.parentElement!;
 
     // Populate quality list
-    let qualityList = content.videojs?.qualityLevels();
-    let qualityNums: number[];
+    let qualityList = content.videojs?.qualityLevels?.();
+    let qualityNums: number[] | undefined;
     if (qualityList && qualityList.length >= 1) {
       const s = new Set<number>();
       let hasMax = false;
       for (let i = 0; i < qualityList?.length; i++) {
         const { width, height, label } = qualityList[i];
-        s.add(Math.min(width, height));
+        s.add(Math.min(width!, height!));
 
         if (label?.includes("max.m3u8")) {
           hasMax = true;
@@ -351,10 +356,10 @@ class VideoContentSetup {
         options: qualityNums,
         forced: true,
         onChange: (quality: number) => {
-          qualityList = content.videojs?.qualityLevels();
+          qualityList = content.videojs?.qualityLevels?.();
           if (!qualityList || !content.videojs) return;
 
-          const isHLS = content.videojs.src(undefined).includes("m3u8");
+          const isHLS = content.videojs.src(undefined)?.includes("m3u8");
 
           if (quality === -2) {
             // Direct playback
@@ -378,7 +383,7 @@ class VideoContentSetup {
           // Enable only the selected quality
           for (let i = 0; i < qualityList.length; ++i) {
             const { width, height, label } = qualityList[i];
-            const pixels = Math.min(width, height);
+            const pixels = Math.min(width!, height!);
             qualityList[i].enabled =
               !quality || // auto
               pixels === quality || // exact match
@@ -390,40 +395,42 @@ class VideoContentSetup {
 
     // Initialize Plyr and custom CSS
     const plyr = new Plyr(content.videoElement, opts);
-    plyr.elements.container.style.height = "100%";
-    plyr.elements.container.style.width = "100%";
-    plyr.elements.container
+    const container = plyr.elements.container!;
+
+    container.style.height = "100%";
+    container.style.width = "100%";
+    container
       .querySelectorAll("button")
       .forEach((el) => el.classList.add("button-vue"));
-    plyr.elements.container
+    container
       .querySelectorAll("progress")
       .forEach((el) => el.classList.add("vue"));
-    plyr.elements.container.style.backgroundColor = "transparent";
-    plyr.elements.wrapper.style.backgroundColor = "transparent";
+    container.style.backgroundColor = "transparent";
+    plyr.elements.wrapper!.style.backgroundColor = "transparent";
 
     // Set the fullscreen element to the container
-    plyr.elements.fullscreen = content.slide.holderElement;
+    plyr.elements.fullscreen = content.slide?.holderElement || null;
 
     // Done with init
     content.plyr = plyr;
 
     // Wait for animation to end before showing Plyr
-    plyr.elements.container.style.opacity = "0";
+    container.style.opacity = "0";
     setTimeout(() => {
-      plyr.elements.container.style.opacity = "1";
+      container.style.opacity = "1";
     }, 250);
 
     // Restore original parent of video element
     origParent.appendChild(content.videoElement);
     // Move plyr to the slide container
-    content.slide.holderElement.appendChild(plyr.elements.container);
+    content.slide?.holderElement?.appendChild(container);
 
     // Add fullscreen orientation hooks
     if (screen.orientation?.lock) {
       // Store the previous orientation
       // This is because unlocking (at least on Chrome) does
       // not restore the previous orientation
-      let previousOrientation: OrientationLockType;
+      let previousOrientation: OrientationLockType | undefined;
 
       // Lock orientation when entering fullscreen
       plyr.on("enterfullscreen", async (event) => {
@@ -461,25 +468,25 @@ class VideoContentSetup {
   }
 
   updateRotation(content: VideoContent, val?: number): boolean {
-    if (!content.videojs) return;
+    if (!content.videojs) return false;
 
     content.videoElement = content.videojs.el()?.querySelector("video");
-    if (!content.videoElement) return;
+    if (!content.videoElement) return false;
 
     const photo = content.data.photo;
     const exif = photo.imageInfo?.exif;
     const rotation = val ?? Number(exif?.Rotation || 0);
-    const shouldRotate = content.videojs?.src(undefined).includes("m3u8");
+    const shouldRotate = content.videojs?.src(undefined)?.includes("m3u8");
 
     if (rotation && shouldRotate) {
       let transform = `rotate(${rotation}deg)`;
       const hasRotation = rotation === 90 || rotation === 270;
 
       if (hasRotation) {
-        content.videoElement.style.width = content.element.style.height;
-        content.videoElement.style.height = content.element.style.width;
+        content.videoElement.style.width = content.element!.style.height;
+        content.videoElement.style.height = content.element!.style.width;
 
-        transform = `translateY(-${content.element.style.width}) ${transform}`;
+        transform = `translateY(-${content.element!.style.width}) ${transform}`;
         content.videoElement.style.transformOrigin = "bottom left";
       }
 
diff --git a/src/components/viewer/Viewer.vue b/src/components/viewer/Viewer.vue
index ff1eeab4..eea95c5f 100644
--- a/src/components/viewer/Viewer.vue
+++ b/src/components/viewer/Viewer.vue
@@ -237,7 +237,7 @@ export default defineComponent({
 
   data: () => ({
     isOpen: false,
-    originalTitle: null,
+    originalTitle: null as string | null,
     editorOpen: false,
     editorSrc: "",
 
@@ -301,7 +301,7 @@ export default defineComponent({
 
     /** Route is public */
     routeIsPublic(): boolean {
-      return this.$route.name?.endsWith("-share");
+      return this.$route.name?.endsWith("-share") ?? false;
     },
 
     /** Route is album */
@@ -323,7 +323,7 @@ export default defineComponent({
 
     /** Is the current slide a video */
     isVideo(): boolean {
-      return Boolean(this.currentPhoto?.flag & this.c.FLAG_IS_VIDEO);
+      return Boolean((this.currentPhoto?.flag ?? 0) & this.c.FLAG_IS_VIDEO);
     },
 
     /** Is the current slide a live photo */
@@ -354,12 +354,12 @@ export default defineComponent({
 
     /** Show edit buttons */
     canEdit(): boolean {
-      return this.currentPhoto?.imageInfo?.permissions?.includes("U");
+      return this.currentPhoto?.imageInfo?.permissions?.includes("U") ?? false;
     },
 
     /** Show delete button */
     canDelete(): boolean {
-      return this.currentPhoto?.imageInfo?.permissions?.includes("D");
+      return this.currentPhoto?.imageInfo?.permissions?.includes("D") ?? false;
     },
 
     /** Show share button */
@@ -399,7 +399,7 @@ export default defineComponent({
       const photo = this.currentPhoto;
       const isvideo = photo && photo.flag & this.c.FLAG_IS_VIDEO;
       if (photo && !isvideo && photo.fileid === fileid) {
-        this.photoswipe.refreshSlideContent(this.currIndex);
+        this.photoswipe?.refreshSlideContent(this.currIndex);
       }
     },
 
@@ -487,7 +487,7 @@ export default defineComponent({
         ) {
           return;
         }
-        _onFocusIn.call(this.photoswipe.keyboard, e);
+        _onFocusIn.call(this.photoswipe!.keyboard, e);
       };
 
       // Refresh sidebar on change
@@ -556,7 +556,7 @@ export default defineComponent({
 
       // Update vue route for deep linking
       this.photoswipe.on("slideActivate", (e) => {
-        this.currIndex = this.photoswipe.currIndex;
+        this.currIndex = this.photoswipe!.currIndex;
         const photo = e.slide?.data?.photo;
         this.setRouteHash(photo);
         this.updateTitle(photo);
@@ -619,15 +619,20 @@ export default defineComponent({
     },
 
     /** Open using start photo and rows list */
-    async open(anchorPhoto: IPhoto, rows?: IRow[]) {
-      this.list = [...anchorPhoto.d.detail];
-      let startIndex = -1;
+    async open(anchorPhoto: IPhoto, rows: IRow[]) {
+      const detail = anchorPhoto.d?.detail;
+      if (!detail) {
+        console.error("Attempted to open viewer with no detail list!");
+        return;
+      }
+
+      this.list = [...detail];
+      const startIndex = detail.indexOf(anchorPhoto);
 
       // Get days list and map
       for (const r of rows) {
         if (r.type === IRowType.HEAD) {
-          if (r.day.dayid == anchorPhoto.d.dayid) {
-            startIndex = r.day.detail.indexOf(anchorPhoto);
+          if (r.day.dayid == anchorPhoto.dayid) {
             this.globalAnchor = this.globalCount;
           }
 
@@ -638,18 +643,18 @@ export default defineComponent({
       }
 
       // Create basic viewer
-      await this.createBase({
+      const photoswipe = await this.createBase({
         index: this.globalAnchor + startIndex,
       });
 
       // Lazy-generate item data.
       // Load the next two days in the timeline.
-      this.photoswipe.addFilter("itemData", (itemData, index) => {
+      photoswipe.addFilter("itemData", (itemData, index) => {
         // Get photo object from list
         let idx = index - this.globalAnchor;
         if (idx < 0) {
           // Load previous day
-          const firstDayId = this.list[0].d.dayid;
+          const firstDayId = this.list[0].dayid;
           const firstDayIdx = utils.binarySearch(this.dayIds, firstDayId);
           if (firstDayIdx === 0) {
             // No previous day
@@ -657,7 +662,7 @@ export default defineComponent({
           }
           const prevDayId = this.dayIds[firstDayIdx - 1];
           const prevDay = this.days.get(prevDayId);
-          if (!prevDay.detail) {
+          if (!prevDay?.detail) {
             console.error("[BUG] No detail for previous day");
             return {};
           }
@@ -665,7 +670,7 @@ export default defineComponent({
           this.globalAnchor -= prevDay.count;
         } else if (idx >= this.list.length) {
           // Load next day
-          const lastDayId = this.list[this.list.length - 1].d.dayid;
+          const lastDayId = this.list[this.list.length - 1].dayid;
           const lastDayIdx = utils.binarySearch(this.dayIds, lastDayId);
           if (lastDayIdx === this.dayIds.length - 1) {
             // No next day
@@ -673,7 +678,7 @@ export default defineComponent({
           }
           const nextDayId = this.dayIds[lastDayIdx + 1];
           const nextDay = this.days.get(nextDayId);
-          if (!nextDay.detail) {
+          if (!nextDay?.detail) {
             console.error("[BUG] No detail for next day");
             return {};
           }
@@ -689,12 +694,12 @@ export default defineComponent({
         }
 
         // Preload next and previous 3 days
-        const dayIdx = utils.binarySearch(this.dayIds, photo.d.dayid);
+        const dayIdx = utils.binarySearch(this.dayIds, photo.dayid);
         const preload = (idx: number) => {
           if (
             idx > 0 &&
             idx < this.dayIds.length &&
-            !this.days.get(this.dayIds[idx]).detail
+            !this.days.get(this.dayIds[idx])?.detail
           ) {
             this.fetchDay(this.dayIds[idx]);
           }
@@ -719,13 +724,13 @@ export default defineComponent({
       });
 
       // Get the thumbnail image
-      this.photoswipe.addFilter("thumbEl", (thumbEl, data, index) => {
+      photoswipe.addFilter("thumbEl", (thumbEl, data, index) => {
         const photo = this.list[index - this.globalAnchor];
-        if (!photo || !photo.w || !photo.h) return thumbEl;
-        return this.thumbElem(photo) || thumbEl;
+        if (!photo || !photo.w || !photo.h) return thumbEl as HTMLElement;
+        return this.thumbElem(photo) ?? (thumbEl as HTMLElement); // bug in PhotoSwipe types
       });
 
-      this.photoswipe.on("slideActivate", (e) => {
+      photoswipe.on("slideActivate", (e) => {
         // Scroll to keep the thumbnail in view
         const thumb = this.thumbElem(e.slide.data?.photo);
         if (thumb && this.fullyOpened) {
@@ -741,13 +746,13 @@ export default defineComponent({
         }
 
         // Remove active class from others and add to this one
-        this.photoswipe.element
-          .querySelectorAll(".pswp__item")
+        photoswipe.element
+          ?.querySelectorAll(".pswp__item")
           .forEach((el) => el.classList.remove("active"));
         e.slide.holderElement?.classList.add("active");
       });
 
-      this.photoswipe.init();
+      photoswipe.init();
     },
 
     /** Close the viewer */
@@ -758,14 +763,14 @@ export default defineComponent({
     /** Open with a static list of photos */
     async openStatic(photo: IPhoto, list: IPhoto[], thumbSize?: number) {
       this.list = list;
-      await this.createBase({
+      const photoswipe = await this.createBase({
         index: list.findIndex((p) => p.fileid === photo.fileid),
       });
 
       this.globalCount = list.length;
       this.globalAnchor = 0;
 
-      this.photoswipe.addFilter("itemData", (itemData, index) => ({
+      photoswipe.addFilter("itemData", (itemData, index) => ({
         ...this.getItemData(this.list[index]),
         msrc: thumbSize
           ? utils.getPreviewUrl(photo, false, thumbSize)
@@ -773,7 +778,7 @@ export default defineComponent({
       }));
 
       this.isOpen = true;
-      this.photoswipe.init();
+      photoswipe!.init();
     },
 
     /** Get base data object */
@@ -849,7 +854,7 @@ export default defineComponent({
       if (important.length > 0) return important[0] as HTMLImageElement;
 
       // Find element within 500px of the screen top
-      let elem: HTMLImageElement;
+      let elem: HTMLImageElement | undefined;
       elems.forEach((e) => {
         const rect = e.getBoundingClientRect();
         if (rect.top > -500) {
@@ -896,7 +901,7 @@ export default defineComponent({
       if (!this.canEdit) return;
 
       // Prevent editing Live Photos
-      if (this.currentPhoto.liveid) {
+      if (this.isLivePhoto) {
         showError(
           this.t("memories", "Editing is currently disabled for Live Photos")
         );
@@ -909,7 +914,7 @@ export default defineComponent({
 
     /** Share the current photo externally */
     async shareCurrent() {
-      globalThis.sharePhoto(this.currentPhoto);
+      globalThis.sharePhoto(this.currentPhoto!);
     },
 
     /** Key press events */
@@ -925,7 +930,7 @@ export default defineComponent({
 
     /** Delete this photo and refresh */
     async deleteCurrent() {
-      let idx = this.photoswipe.currIndex - this.globalAnchor;
+      let idx = this.photoswipe!.currIndex - this.globalAnchor;
       const photo = this.list[idx];
       if (!photo) return;
 
@@ -950,22 +955,24 @@ export default defineComponent({
       // If this is the last photo, move to the previous photo first
       // https://github.com/pulsejet/memories/issues/269
       if (idx === this.list.length - 1) {
-        this.photoswipe.prev();
+        this.photoswipe!.prev();
 
         // Some photos might lazy load, so recompute idx for the next element
-        idx = this.photoswipe.currIndex + 1 - this.globalAnchor;
+        idx = this.photoswipe!.currIndex + 1 - this.globalAnchor;
       }
 
       this.list.splice(idx, 1);
       this.globalCount--;
       for (let i = idx - 3; i <= idx + 3; i++) {
-        this.photoswipe.refreshSlideContent(i + this.globalAnchor);
+        this.photoswipe!.refreshSlideContent(i + this.globalAnchor);
       }
     },
 
     /** Play the current live photo */
     playLivePhoto() {
-      this.psLivePhoto.onContentActivate(this.photoswipe.currSlide as PsSlide);
+      this.psLivePhoto?.onContentActivate(
+        this.photoswipe!.currSlide as PsSlide
+      );
     },
 
     /** Is the current photo a favorite */
@@ -977,7 +984,7 @@ export default defineComponent({
 
     /** Favorite the current photo */
     async favoriteCurrent() {
-      const photo = this.currentPhoto;
+      const photo = this.currentPhoto!;
       const val = !this.isFavorite();
       try {
         this.updateLoading(1);
@@ -1014,7 +1021,7 @@ export default defineComponent({
     /** Open the sidebar */
     async openSidebar(photo?: IPhoto) {
       globalThis.mSidebar.setTab("memories-metadata");
-      photo ||= this.currentPhoto;
+      photo ??= this.currentPhoto!;
 
       if (this.routeIsPublic) {
         globalThis.mSidebar.open(photo.fileid);
@@ -1052,7 +1059,7 @@ export default defineComponent({
     closeSidebar() {
       this.hideSidebar();
       this.sidebarOpen = false;
-      this.photoswipe.updateSize();
+      this.photoswipe?.updateSize();
     },
 
     /** Toggle the sidebar visibility */
@@ -1101,7 +1108,7 @@ export default defineComponent({
       // If this is a video, wait for it to finish
       if (this.isVideo) {
         // Get active video element
-        const video: HTMLVideoElement = this.photoswipe?.element?.querySelector(
+        const video = this.photoswipe?.element?.querySelector<HTMLVideoElement>(
           ".pswp__item.active video"
         );
 
@@ -1114,7 +1121,7 @@ export default defineComponent({
         }
       }
 
-      this.photoswipe.next();
+      this.photoswipe?.next();
       // no need to set the timer again, since next
       // calls resetSlideshowTimer anyway
     },
diff --git a/src/components/viewer/types.ts b/src/components/viewer/types.ts
index 831ca7a8..2388ef46 100644
--- a/src/components/viewer/types.ts
+++ b/src/components/viewer/types.ts
@@ -4,10 +4,15 @@ import { IPhoto } from "../../types";
 
 type PsAugment = {
   data: _SlideData & {
-    photo?: IPhoto;
+    src: string;
+    msrc: string;
+    photo: IPhoto;
   };
 };
-export type PsSlide = Slide & PsAugment;
+export type PsSlide = Slide &
+  PsAugment & {
+    content: PsContent;
+  };
 export type PsContent = Content & PsAugment;
 export type PsEvent = {
   content: PsContent;
diff --git a/src/main.ts b/src/main.ts
index 6530a2d1..c06e55a2 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -1,5 +1,3 @@
-/// <reference types="@nextcloud/typings" />
-
 import "reflect-metadata";
 import Vue from "vue";
 import VueVirtualScroller from "vue-virtual-scroller";
@@ -10,11 +8,11 @@ import GlobalMixin from "./mixins/GlobalMixin";
 import App from "./App.vue";
 import Admin from "./Admin.vue";
 import router from "./router";
-import { Route } from "vue-router";
 import { generateFilePath } from "@nextcloud/router";
 import { getRequestToken } from "@nextcloud/auth";
-import { IPhoto } from "./types";
 
+import type { Route } from "vue-router";
+import type { IPhoto } from "./types";
 import type PlyrType from "plyr";
 import type videojsType from "video.js";
 
@@ -61,7 +59,7 @@ globalThis.windowInnerWidth = window.innerWidth;
 globalThis.windowInnerHeight = window.innerHeight;
 
 // CSP config for webpack dynamic chunk loading
-__webpack_nonce__ = window.btoa(getRequestToken());
+__webpack_nonce__ = window.btoa(getRequestToken() ?? "");
 
 // Correct the root of the app for chunk loading
 // OC.linkTo matches the apps folders
@@ -71,21 +69,17 @@ __webpack_public_path__ = generateFilePath("memories", "", "js/");
 
 // Generate client id for this instance
 // Does not need to be cryptographically secure
-const getClientId = () =>
+const getClientId = (): string =>
   Math.random().toString(36).substring(2, 15).padEnd(12, "0");
 globalThis.videoClientId = getClientId();
-globalThis.videoClientIdPersistent = localStorage.getItem(
-  "videoClientIdPersistent"
+globalThis.videoClientIdPersistent =
+  localStorage.getItem("videoClientIdPersistent") ?? getClientId();
+localStorage.setItem(
+  "videoClientIdPersistent",
+  globalThis.videoClientIdPersistent
 );
-if (!globalThis.videoClientIdPersistent) {
-  globalThis.videoClientIdPersistent = getClientId();
-  localStorage.setItem(
-    "videoClientIdPersistent",
-    globalThis.videoClientIdPersistent
-  );
-}
 
-Vue.mixin(GlobalMixin);
+Vue.mixin(GlobalMixin as any);
 Vue.use(VueVirtualScroller);
 Vue.component("XImg", XImg);
 
diff --git a/src/router.ts b/src/router.ts
index f48faedc..840c84f4 100644
--- a/src/router.ts
+++ b/src/router.ts
@@ -1,5 +1,5 @@
 import { generateUrl } from "@nextcloud/router";
-import { translate as t, translatePlural as n } from "@nextcloud/l10n";
+import { translate as t } from "@nextcloud/l10n";
 import Router from "vue-router";
 import Vue from "vue";
 import Timeline from "./components/Timeline.vue";
diff --git a/src/service-worker.js b/src/service-worker.js
index 3903a0be..43a08b07 100644
--- a/src/service-worker.js
+++ b/src/service-worker.js
@@ -1,32 +1,35 @@
 import { precacheAndRoute } from "workbox-precaching";
-import { NetworkFirst, CacheFirst, NetworkOnly } from "workbox-strategies";
+import { NetworkFirst, CacheFirst } from "workbox-strategies";
 import { registerRoute } from "workbox-routing";
 import { ExpirationPlugin } from "workbox-expiration";
 
 precacheAndRoute(self.__WB_MANIFEST);
 
-registerRoute(/^.*\/apps\/memories\/api\/video\/livephoto\/.*/, new CacheFirst({
-  cacheName: "livephotos",
-  plugins: [
-    new ExpirationPlugin({
-      maxAgeSeconds: 3600 * 24 * 7, // days
-      maxEntries: 1000, // 1k videos
-    }),
-  ],
-}));
+registerRoute(
+  /^.*\/apps\/memories\/api\/video\/livephoto\/.*/,
+  new CacheFirst({
+    cacheName: "livephotos",
+    plugins: [
+      new ExpirationPlugin({
+        maxAgeSeconds: 3600 * 24 * 7, // days
+        maxEntries: 1000, // 1k videos
+      }),
+    ],
+  })
+);
 
 // Important: Using the NetworkOnly strategy and not registering
 // a route are NOT equivalent. The NetworkOnly strategy will
 // strip certain headers such as HTTP-Range, which is required
 // for proper playback of videos.
 
-const networkOnly = [
-  /^.*\/apps\/memories\/api\/.*/,
-];
+const networkOnly = [/^.*\/apps\/memories\/api\/.*/];
 
 // Cache pages for same-origin requests only
 registerRoute(
-  ({ url }) => url.origin === self.location.origin && !networkOnly.some((regex) => regex.test(url.href)),
+  ({ url }) =>
+    url.origin === self.location.origin &&
+    !networkOnly.some((regex) => regex.test(url.href)),
   new NetworkFirst({
     cacheName: "pages",
     plugins: [
diff --git a/src/services/API.ts b/src/services/API.ts
index 35837638..2b047db3 100644
--- a/src/services/API.ts
+++ b/src/services/API.ts
@@ -45,11 +45,11 @@ export class API {
 
     if (typeof query === "object") {
       // Clean up undefined and null
-      Object.keys(query).forEach((key) => {
+      for (const key of Object.keys(query)) {
         if (query[key] === undefined || query[key] === null) {
           delete query[key];
         }
-      });
+      }
 
       // Check if nothing in query
       if (!Object.keys(query).length) return url;
@@ -138,7 +138,7 @@ export class API {
     return gen(`${BASE}/image/set-exif/{id}`, { id });
   }
 
-  static IMAGE_DECODABLE(id: number, etag: string) {
+  static IMAGE_DECODABLE(id: number, etag?: string) {
     return tok(API.Q(gen(`${BASE}/image/decodable/{id}`, { id }), { etag }));
   }
 
diff --git a/src/services/dav/albums.ts b/src/services/dav/albums.ts
index 5ba4a8f4..d095c699 100644
--- a/src/services/dav/albums.ts
+++ b/src/services/dav/albums.ts
@@ -104,7 +104,7 @@ export async function* removeFromAlbum(
     } catch (e) {
       showError(
         t("memories", "Failed to remove {filename}.", {
-          filename: f.basename,
+          filename: f.basename ?? f.fileid,
         })
       );
       return 0;
diff --git a/src/services/dav/base.ts b/src/services/dav/base.ts
index abedf158..1edcea7a 100644
--- a/src/services/dav/base.ts
+++ b/src/services/dav/base.ts
@@ -60,7 +60,7 @@ export async function getFiles(photos: IPhoto[]): Promise<IFileInfo[]> {
   const fileIds = photos.map((photo) => photo.fileid);
 
   // Divide fileIds into chunks of GET_FILE_CHUNK_SIZE
-  const chunks = [];
+  const chunks: number[][] = [];
   for (let i = 0; i < fileIds.length; i += GET_FILE_CHUNK_SIZE) {
     chunks.push(fileIds.slice(i, i + GET_FILE_CHUNK_SIZE));
   }
diff --git a/src/services/dav/face.ts b/src/services/dav/face.ts
index 31d1e003..c0e6f3aa 100644
--- a/src/services/dav/face.ts
+++ b/src/services/dav/face.ts
@@ -70,7 +70,7 @@ export async function* removeFaceImages(
       console.error(e);
       showError(
         t("memories", "Failed to remove {filename} from face.", {
-          filename: f.basename,
+          filename: f.basename ?? f.fileid,
         })
       );
       return 0;
diff --git a/src/services/dav/favorites.ts b/src/services/dav/favorites.ts
index 5f774c40..4af68260 100644
--- a/src/services/dav/favorites.ts
+++ b/src/services/dav/favorites.ts
@@ -62,7 +62,7 @@ export async function* favoritePhotos(
   const calls = fileInfos.map((fileInfo) => async () => {
     try {
       await favoriteFile(fileInfo.originalFilename, favoriteState);
-      const photo = photos.find((p) => p.fileid === fileInfo.fileid);
+      const photo = photos.find((p) => p.fileid === fileInfo.fileid)!;
       if (favoriteState) {
         photo.flag |= utils.constants.c.FLAG_IS_FAVORITE;
       } else {
diff --git a/src/services/dav/onthisday.ts b/src/services/dav/onthisday.ts
index 71d162d0..7c69798c 100644
--- a/src/services/dav/onthisday.ts
+++ b/src/services/dav/onthisday.ts
@@ -57,7 +57,7 @@ export async function getOnThisDayData(): Promise<IDay[]> {
 
     // Add to last day
     const day = ans[ans.length - 1];
-    day.detail.push(photo);
+    day.detail!.push(photo);
     day.count++;
   }
 
diff --git a/src/services/dav/single-item.ts b/src/services/dav/single-item.ts
index 0d3f7652..fc3293a4 100644
--- a/src/services/dav/single-item.ts
+++ b/src/services/dav/single-item.ts
@@ -1,7 +1,7 @@
 import { IDay } from "../../types";
 import { loadState } from "@nextcloud/initial-state";
 
-let singleItem = null;
+let singleItem: any;
 try {
   singleItem = loadState("memories", "single_item", {});
 } catch (e) {
diff --git a/src/services/strings.ts b/src/services/strings.ts
index 0e5f5dd3..e64b5d1d 100644
--- a/src/services/strings.ts
+++ b/src/services/strings.ts
@@ -5,7 +5,9 @@ const config_facerecognitionEnabled = Boolean(
   loadState("memories", "facerecognitionEnabled", <string>"")
 );
 
-export function emptyDescription(routeName: string): string {
+type RouteNameType = string | null | undefined;
+
+export function emptyDescription(routeName: RouteNameType): string {
   switch (routeName) {
     case "timeline":
       return t(
@@ -45,7 +47,7 @@ export function emptyDescription(routeName: string): string {
   }
 }
 
-export function viewName(routeName: string): string {
+export function viewName(routeName: RouteNameType): string {
   switch (routeName) {
     case "timeline":
       return t("memories", "Your Timeline");
diff --git a/src/services/utils/algo.ts b/src/services/utils/algo.ts
index 332538d7..fc2be7d3 100644
--- a/src/services/utils/algo.ts
+++ b/src/services/utils/algo.ts
@@ -86,7 +86,7 @@ export function randomSubarray(arr: any[], size: number) {
 export function setRenewingTimeout(
   ctx: any,
   name: string,
-  callback: () => void | null,
+  callback: (() => void) | null,
   delay: number
 ) {
   if (ctx[name]) window.clearTimeout(ctx[name]);
diff --git a/src/services/utils/cache.ts b/src/services/utils/cache.ts
index 1e049d69..4f8ffa72 100644
--- a/src/services/utils/cache.ts
+++ b/src/services/utils/cache.ts
@@ -35,13 +35,13 @@ export async function openCache() {
 }
 
 /** Get data from the cache */
-export async function getCachedData<T>(url: string): Promise<T> {
+export async function getCachedData<T>(url: string): Promise<T | null> {
   if (!window.caches) return null;
   const cache = staticCache || (await openCache());
   if (!cache) return null;
 
   const cachedResponse = await cache.match(url);
-  if (!cachedResponse || !cachedResponse.ok) return undefined;
+  if (!cachedResponse || !cachedResponse.ok) return null;
   return await cachedResponse.json();
 }
 
diff --git a/src/types.ts b/src/types.ts
index a11c39d5..764c6ad0 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -6,7 +6,7 @@ export type IFileInfo = {
   /** Full file name, e.g. /pi/test/Qx0dq7dvEXA.jpg */
   filename: string;
   /** Original file name, e.g. /files/admin/pi/test/Qx0dq7dvEXA.jpg */
-  originalFilename?: string;
+  originalFilename: string;
   /** Base name of file e.g. Qx0dq7dvEXA.jpg */
   basename: string;
 };
@@ -36,7 +36,7 @@ export type IPhoto = {
   /** Bit flags */
   flag: number;
   /** DayID from server */
-  dayid?: number;
+  dayid: number;
   /** Width of full image */
   w?: number;
   /** Height of full image */
@@ -58,7 +58,7 @@ export type IPhoto = {
   /** Reference to day object */
   d?: IDay;
   /** Reference to exif object */
-  imageInfo?: IImageInfo;
+  imageInfo?: IImageInfo | null;
 
   /** Face detection ID */
   faceid?: number;
@@ -174,7 +174,7 @@ export type IRow = {
   photos?: IPhoto[];
 
   /** Height in px of the row */
-  size?: number;
+  size: number;
   /** Count of placeholders to create */
   pct?: number;
   /** Don't remove dom element */
diff --git a/src/vue-globals.d.ts b/src/vue-globals.d.ts
index 9483b803..f53ebcff 100644
--- a/src/vue-globals.d.ts
+++ b/src/vue-globals.d.ts
@@ -1,11 +1,11 @@
-import { constants } from "./services/Utils";
-import { translate as t, translatePlural as n } from "@nextcloud/l10n";
+import { type constants } from "./services/Utils";
+import type { translate, translatePlural } from "@nextcloud/l10n";
 
 declare module "vue" {
   interface ComponentCustomProperties {
     // GlobalMixin.ts
-    t: typeof t;
-    n: typeof n;
+    t: typeof translate;
+    n: typeof translatePlural;
 
     c: typeof constants.c;
 
@@ -31,14 +31,8 @@ declare module "vue" {
     config_albumListSort: 1 | 2;
     config_eventName: string;
 
-    updateSetting(setting: string): Promise<void>;
-    updateLocalSetting({
-      setting,
-      value,
-    }: {
-      setting: string;
-      value: any;
-    }): void;
+    updateSetting: (setting: string) => Promise<void>;
+    updateLocalSetting: (opts: { setting: string; value: any }) => void;
   }
 }
 
diff --git a/src/vue-shims.d.ts b/src/vue-shims.d.ts
index aebd6dbd..ebfab37a 100644
--- a/src/vue-shims.d.ts
+++ b/src/vue-shims.d.ts
@@ -1,5 +1,5 @@
 declare module "*.vue" {
-  import { defineComponent } from "vue";
+  import type { defineComponent } from "vue";
   const Component: ReturnType<typeof defineComponent>;
   export default Component;
 }
diff --git a/src/worker.ts b/src/worker.ts
index 36710f4c..d904d4c6 100644
--- a/src/worker.ts
+++ b/src/worker.ts
@@ -1,9 +1,17 @@
 /** Set the receiver function for a worker */
-export function workerExport(handlers: {
-  [key: string]: (...data: any) => Promise<any>;
-}) {
+export function workerExport(
+  handlers: Record<string, (...data: any) => Promise<any>>
+): void {
   /** Promise API for web worker */
-  self.onmessage = async ({ data }) => {
+  self.onmessage = async ({
+    data,
+  }: {
+    data: {
+      id: number;
+      name: string;
+      args: any[];
+    };
+  }) => {
     try {
       const handler = handlers[data.name];
       if (!handler) throw new Error(`No handler for type ${data.name}`);
@@ -23,22 +31,23 @@ export function workerExport(handlers: {
 
 /** Get the CALL function for a worker. Call this only once. */
 export function workerImporter(worker: Worker) {
-  const promises: { [id: string]: any } = {};
+  const promises = new Map<number, { resolve: any; reject: any }>();
+
   worker.onmessage = ({ data }: { data: any }) => {
     const { id, resolve, reject } = data;
-    if (resolve) promises[id].resolve(resolve);
-    if (reject) promises[id].reject(reject);
-    delete promises[id];
+    if (resolve) promises.get(id)?.resolve(resolve);
+    if (reject) promises.get(id)?.reject(reject);
+    promises.delete(id);
   };
-  return function importer<F extends (...args: any) => Promise<any>>(
-    name: string
-  ): (...args: Parameters<F>) => ReturnType<F> {
-    return function fun(...args: any) {
-      return new Promise((resolve, reject) => {
+
+  type PromiseFun = (...args: any) => Promise<any>;
+  return function importer<F extends PromiseFun>(name: string) {
+    return async function fun(...args: Parameters<F>) {
+      return await new Promise<ReturnType<Awaited<F>>>((resolve, reject) => {
         const id = Math.random();
-        promises[id] = { resolve, reject };
+        promises.set(id, { resolve, reject });
         worker.postMessage({ id, name, args });
       });
-    } as any;
+    };
   };
 }
diff --git a/tsconfig.json b/tsconfig.json
index 0477ade7..9d6e063f 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -9,7 +9,8 @@
     "jsx": "preserve",
     "useDefineForClassFields": true,
     "noImplicitThis": true,
-    "esModuleInterop": true
+    "esModuleInterop": true,
+    "strictNullChecks": true
   },
   "vueCompilerOptions": {
     "target": 2.7