Fix a bunch of type errors and add a type-check to the github workflows (#837)

* Add yarn type-check

* Rename to yarn typecheck

* Fix a collection of type errors

* Add typecheck to automated tests

* add `dist` to exluded folders tsconfig

---------

Co-authored-by: Ansh Nanda <anshnanda10@gmail.com>

src/lib/api/api-polyfill.ts

@@ -11,7 +11,7 @@ export function doPolyfill() {
 interface FetchHandlerResponse {
   status: number
   headers: Record<string, string>
-  body: ArrayBuffer | undefined
+  body: any
 }
 
 async function fetchHandler(

src/lib/api/feed-manip.ts

@@ -74,9 +74,12 @@ export class FeedViewPostsSlice {
   }
 
   flattenReplyParent() {
-    if (this.items[0].reply?.parent) {
-      this.isFlattenedReply = true
-      this.items.splice(0, 0, {post: this.items[0].reply?.parent})
+    if (this.items[0].reply) {
+      const reply = this.items[0].reply
+      if (AppBskyFeedDefs.isPostView(reply.parent)) {
+        this.isFlattenedReply = true
+        this.items.splice(0, 0, {post: reply.parent})
+      }
     }
   }
 }
@@ -130,16 +133,17 @@ export class FeedTuner {
 
     // turn non-threads with reply parents into threads
     for (const slice of slices) {
-      if (
-        !slice.isThread &&
-        !slice.items[0].reason &&
-        slice.items[0].reply?.parent &&
-        !this.seenUris.has(slice.items[0].reply?.parent.uri) &&
-        !soonToBeSeenUris.has(slice.items[0].reply?.parent.uri)
-      ) {
-        const uri = slice.items[0].reply?.parent.uri
-        slice.flattenReplyParent()
-        soonToBeSeenUris.add(uri)
+      if (!slice.isThread && !slice.items[0].reason && slice.items[0].reply) {
+        const reply = slice.items[0].reply
+        if (
+          AppBskyFeedDefs.isPostView(reply.parent) &&
+          !this.seenUris.has(reply.parent.uri) &&
+          !soonToBeSeenUris.has(reply.parent.uri)
+        ) {
+          const uri = reply.parent.uri
+          slice.flattenReplyParent()
+          soonToBeSeenUris.add(uri)
+        }
       }
     }
 
@@ -231,7 +235,12 @@ export class FeedTuner {
 }
 
 function getSelfReplyUri(item: FeedViewPost): string | undefined {
-  return item.reply?.parent.author.did === item.post.author.did
-    ? item.reply?.parent.uri
-    : undefined
+  if (item.reply) {
+    if (AppBskyFeedDefs.isPostView(item.reply.parent)) {
+      return item.reply.parent.author.did === item.post.author.did
+        ? item.reply.parent.uri
+        : undefined
+    }
+  }
+  return undefined
 }

src/lib/hooks/useTimer.ts

@@ -4,7 +4,7 @@ import * as React from 'react'
  * Helper hook to run persistent timers on views
  */
 export function useTimer(time: number, handler: () => void) {
-  const timer = React.useRef(undefined)
+  const timer = React.useRef<undefined | NodeJS.Timeout>(undefined)
 
   // function to restart the timer
   const reset = React.useCallback(() => {