TS strict mode

[Murderlon]

Ref: https://github.com/transloadit/uppy-planning/issues/36#issuecomment-2173650732
Blocked on #5050 (TS errors in provider-views which I'm not fixing to prevent merge conflicts)

• Apply feedback
• Changes for strict mode
• useUnknownInCatchVariables to false as we have many errors from this but there isn't a good way at the moment to type this. Uppy puts properties on errors all over the place, often without proper error classes. So settings this to true would mean hard casting everything with any so might as well let TS set the default to any. Even if we turn it on, the only way to narrow the type is with instanceof which is a check we generally avoid.

We have to decide what to do with allowImportingTsExtensions. I've left it there too because we have many ts imports, particularly in tests. But Remco (strongly) recommended to remove it.

[github-actions]

Diff output files

diff --git a/packages/@uppy/aws-s3/lib/MultipartUploader.js b/packages/@uppy/aws-s3/lib/MultipartUploader.js
index ff1f21c..e104fdc 100644
--- a/packages/@uppy/aws-s3/lib/MultipartUploader.js
+++ b/packages/@uppy/aws-s3/lib/MultipartUploader.js
@@ -69,11 +69,11 @@ class MultipartUploader {
     });
     Object.defineProperty(this, _chunks, {
       writable: true,
-      value: void 0,
+      value: [],
     });
     Object.defineProperty(this, _chunkState, {
       writable: true,
-      value: void 0,
+      value: [],
     });
     Object.defineProperty(this, _data, {
       writable: true,
diff --git a/packages/@uppy/aws-s3/lib/index.js b/packages/@uppy/aws-s3/lib/index.js
index def9666..2171565 100644
--- a/packages/@uppy/aws-s3/lib/index.js
+++ b/packages/@uppy/aws-s3/lib/index.js
@@ -640,7 +640,7 @@ function _uploadLocalFile2(file) {
       log: function() {
         return _this.uppy.log(...arguments);
       },
-      getChunkSize: this.opts.getChunkSize ? this.opts.getChunkSize.bind(this) : null,
+      getChunkSize: this.opts.getChunkSize ? this.opts.getChunkSize.bind(this) : undefined,
       onProgress,
       onError,
       onSuccess,
diff --git a/packages/@uppy/file-input/lib/FileInput.js b/packages/@uppy/file-input/lib/FileInput.js
index c318ddf..b52a1c8 100644
--- a/packages/@uppy/file-input/lib/FileInput.js
+++ b/packages/@uppy/file-input/lib/FileInput.js
@@ -15,6 +15,7 @@ export default class FileInput extends UIPlugin {
       ...defaultOptions,
       ...opts,
     });
+    this.input = null;
     this.id = this.opts.id || "FileInput";
     this.title = "File Input";
     this.type = "acquirer";
diff --git a/packages/@uppy/provider-views/lib/View.js b/packages/@uppy/provider-views/lib/View.js
index 37db53a..01d961f 100644
--- a/packages/@uppy/provider-views/lib/View.js
+++ b/packages/@uppy/provider-views/lib/View.js
@@ -1,6 +1,7 @@
 import remoteFileObjToLocal from "@uppy/utils/lib/remoteFileObjToLocal";
 export default class View {
   constructor(plugin, opts) {
+    this.isShiftKeyPressed = false;
     this.filterItems = items => {
       const state = this.plugin.getPluginState();
       if (!state.filterInput || state.filterInput === "") {
diff --git a/packages/@uppy/screen-capture/lib/RecorderScreen.js b/packages/@uppy/screen-capture/lib/RecorderScreen.js
index 52e5342..ea999a6 100644
--- a/packages/@uppy/screen-capture/lib/RecorderScreen.js
+++ b/packages/@uppy/screen-capture/lib/RecorderScreen.js
@@ -14,6 +14,10 @@ import StopWatch from "./StopWatch.js";
 import StreamStatus from "./StreamStatus.js";
 import SubmitButton from "./SubmitButton.js";
 class RecorderScreen extends Component {
+  constructor() {
+    super(...arguments);
+    this.videoElement = null;
+  }
   componentWillUnmount() {
     const {
       onStop,
diff --git a/packages/@uppy/screen-capture/lib/ScreenCapture.js b/packages/@uppy/screen-capture/lib/ScreenCapture.js
index 0ccc269..009813e 100644
--- a/packages/@uppy/screen-capture/lib/ScreenCapture.js
+++ b/packages/@uppy/screen-capture/lib/ScreenCapture.js
@@ -49,6 +49,12 @@ export default class ScreenCapture extends UIPlugin {
       ...defaultOptions,
       ...opts,
     });
+    this.videoStream = null;
+    this.audioStream = null;
+    this.userDenied = false;
+    this.recorder = null;
+    this.outputStream = null;
+    this.recordingChunks = null;
     this.mediaDevices = getMediaDevices();
     this.protocol = location.protocol === "https:" ? "https" : "http";
     this.id = this.opts.id || "ScreenCapture";
diff --git a/packages/@uppy/screen-capture/lib/StopWatch.js b/packages/@uppy/screen-capture/lib/StopWatch.js
index bf7415e..6e106d5 100644
--- a/packages/@uppy/screen-capture/lib/StopWatch.js
+++ b/packages/@uppy/screen-capture/lib/StopWatch.js
@@ -39,6 +39,7 @@ class StopWatch extends Component {
       fontSize: "3rem",
       fontFamily: "Courier New",
     };
+    this.timerRunning = false;
     this.state = {
       elapsedTime: 0,
     };
diff --git a/packages/@uppy/transloadit/lib/Assembly.js b/packages/@uppy/transloadit/lib/Assembly.js
index f9b896c..ab6526f 100644
--- a/packages/@uppy/transloadit/lib/Assembly.js
+++ b/packages/@uppy/transloadit/lib/Assembly.js
@@ -62,7 +62,7 @@ class TransloaditAssembly extends Emitter {
     });
     Object.defineProperty(this, _sse, {
       writable: true,
-      value: void 0,
+      value: null,
     });
     this.status = assembly;
     this.pollInterval = null;
diff --git a/packages/@uppy/transloadit/lib/index.js b/packages/@uppy/transloadit/lib/index.js
index 77c1526..75d3a12 100644
--- a/packages/@uppy/transloadit/lib/index.js
+++ b/packages/@uppy/transloadit/lib/index.js
@@ -107,6 +107,7 @@ export default class Transloadit extends BasePlugin {
       writable: true,
       value: void 0,
     });
+    this.restored = null;
     Object.defineProperty(this, _onFileUploadURLAvailable, {
       writable: true,
       value: rawFile => {
diff --git a/packages/@uppy/webcam/lib/Webcam.js b/packages/@uppy/webcam/lib/Webcam.js
index 8b0a6c6..5ca7a7f 100644
--- a/packages/@uppy/webcam/lib/Webcam.js
+++ b/packages/@uppy/webcam/lib/Webcam.js
@@ -72,6 +72,10 @@ export default class Webcam extends UIPlugin {
       writable: true,
       value: void 0,
     });
+    this.stream = null;
+    this.recorder = null;
+    this.recordingChunks = null;
+    this.captureInProgress = false;
     this.mediaDevices = getMediaDevices();
     this.supportsUserMedia = !!this.mediaDevices;
     this.protocol = location.protocol.match(/https/i) ? "https" : "http";

[aduh95]

There are some linter failure to address.

Do you want me to implement my proposed feedback (to use ?: instead of | undefined)? I'm happy to do it if that's simpler for you.

• the only way to narrow the type is with instanceof which is a check we generally avoid.

It's not the only way, I think the preferred solution we settled on was to use function isThatErrorType(err: unknown): err is ThatErrorType util functions. But in any case, your argument still applies, it's much simpler to set useUnknownInCatchVariables to false.

[Murderlon]

There are some linter failure to address.

As mentioned I'm waiting for #5050 to land to avoid conflicts in provider-views, which is where CI is failing. But now that I think of it, suppose I can also fix it so we can merge this, since strict mode probably reveals more errors in that PR which should be fixed there.