Conform more code to strict null checking (#10153)

* Conform more code to strict null checking

* Conform more code to strict null checking

* Iterate

* Iterate

src/utils/exportUtils/Exporter.ts

@@ -276,14 +276,14 @@ export default abstract class Exporter {
     protected isReply(event: MatrixEvent): boolean {
         const isEncrypted = event.isEncrypted();
         // If encrypted, in_reply_to lies in event.event.content
-        const content = isEncrypted ? event.event.content : event.getContent();
+        const content = isEncrypted ? event.event.content! : event.getContent();
         const relatesTo = content["m.relates_to"];
         return !!(relatesTo && relatesTo["m.in_reply_to"]);
     }
 
     protected isAttachment(mxEv: MatrixEvent): boolean {
         const attachmentTypes = ["m.sticker", "m.image", "m.file", "m.video", "m.audio"];
-        return mxEv.getType() === attachmentTypes[0] || attachmentTypes.includes(mxEv.getContent().msgtype);
+        return mxEv.getType() === attachmentTypes[0] || attachmentTypes.includes(mxEv.getContent().msgtype!);
     }
 
     public abstract export(): Promise<void>;

src/utils/exportUtils/HtmlExport.tsx

@@ -217,10 +217,10 @@ export default class HTMLExporter extends Exporter {
         </html>`;
     }
 
-    protected getAvatarURL(event: MatrixEvent): string | undefined {
+    protected getAvatarURL(event: MatrixEvent): string | null {
         const member = event.sender;
         const avatarUrl = member?.getMxcAvatarUrl();
-        return avatarUrl ? mediaFromMxc(avatarUrl).getThumbnailOfSourceHttp(30, 30, "crop") : undefined;
+        return avatarUrl ? mediaFromMxc(avatarUrl).getThumbnailOfSourceHttp(30, 30, "crop") : null;
     }
 
     protected async saveAvatarIfNeeded(event: MatrixEvent): Promise<void> {
@@ -386,7 +386,7 @@ export default class HTMLExporter extends Exporter {
 
     protected async createHTML(events: MatrixEvent[], start: number): Promise<string> {
         let content = "";
-        let prevEvent = null;
+        let prevEvent: MatrixEvent | null = null;
         for (let i = start; i < Math.min(start + 1000, events.length); i++) {
             const event = events[i];
             this.updateProgress(

src/utils/exportUtils/JSONExport.ts

@@ -47,7 +47,7 @@ export default class JSONExporter extends Exporter {
         const creator = this.room.currentState.getStateEvents(EventType.RoomCreate, "")?.getSender();
         const creatorName = this.room?.getMember(creator)?.rawDisplayName || creator;
         const topic = this.room.currentState.getStateEvents(EventType.RoomTopic, "")?.getContent()?.topic || "";
-        const exporter = this.client.getUserId();
+        const exporter = this.client.getUserId()!;
         const exporterName = this.room?.getMember(exporter)?.rawDisplayName || exporter;
         const jsonObject = {
             room_name: this.room.name,

src/utils/exportUtils/exportCSS.ts

@@ -45,7 +45,7 @@ async function getRulesFromCssFile(path: string): Promise<CSSStyleSheet> {
     // the style will only be parsed once it is added to a document
     doc.body.appendChild(styleElement);
 
-    return styleElement.sheet;
+    return styleElement.sheet!;
 }
 
 // naively culls unused css rules based on which classes are present in the html,