Allow PSD uploads over 6MB

You can't currently upload PSD files over 6MB. This is because its
mimetype is `image/vnd.adobe.photoshop`. We think this is an image, and
non-GIF images have a limit of 6MB.

To fix this, we could do one of two things:

1. Add a special case for PSD files
2. Increase the size limit for unsupported image types such as this

I went with the second option.

Tested this by:

- adding automated tests
- uploading a ~9 MB PSD file
- uploading a ~1 MB PNG
- uploading a ~27 MB PNG (which worked because it's converted to a smaller JPEG)
- uploading a ~50 MB text file
- trying to upload a ~500 MB text file (which failed, as expected)

Addresses [DESKTOP-1168][].

[DESKTOP-1168]: https://signalmessenger.atlassian.net/browse/DESKTOP-1168

js/modules/types/attachment.js

@@ -1,4 +1,4 @@
-// Copyright 2018-2020 Signal Messenger, LLC
+// Copyright 2018-2021 Signal Messenger, LLC
 // SPDX-License-Identifier: AGPL-3.0-only
 
 const is = require('@sindresorhus/is');
@@ -217,6 +217,7 @@ exports.isImage = AttachmentTS.isImage;
 exports.isVideo = AttachmentTS.isVideo;
 exports.isAudio = AttachmentTS.isAudio;
 exports.isVoiceMessage = AttachmentTS.isVoiceMessage;
+exports.getUploadSizeLimitKb = AttachmentTS.getUploadSizeLimitKb;
 exports.save = AttachmentTS.save;
 
 const THUMBNAIL_SIZE = 150;

ts/test-node/types/Attachment_test.ts

@@ -1,4 +1,4 @@
-// Copyright 2018-2020 Signal Messenger, LLC
+// Copyright 2018-2021 Signal Messenger, LLC
 // SPDX-License-Identifier: AGPL-3.0-only
 
 import { assert } from 'chai';
@@ -9,6 +9,31 @@ import { SignalService } from '../../protobuf';
 import { stringToArrayBuffer } from '../../../js/modules/string_to_array_buffer';
 
 describe('Attachment', () => {
+  describe('getUploadSizeLimitKb', () => {
+    const { getUploadSizeLimitKb } = Attachment;
+
+    it('returns 6000 kilobytes for supported non-GIF images', () => {
+      assert.strictEqual(getUploadSizeLimitKb(MIME.IMAGE_JPEG), 6000);
+      assert.strictEqual(getUploadSizeLimitKb(MIME.IMAGE_PNG), 6000);
+      assert.strictEqual(getUploadSizeLimitKb(MIME.IMAGE_WEBP), 6000);
+    });
+
+    it('returns 25000 kilobytes for GIFs', () => {
+      assert.strictEqual(getUploadSizeLimitKb(MIME.IMAGE_GIF), 25000);
+    });
+
+    it('returns 100000 for other file types', () => {
+      assert.strictEqual(getUploadSizeLimitKb(MIME.APPLICATION_JSON), 100000);
+      assert.strictEqual(getUploadSizeLimitKb(MIME.AUDIO_AAC), 100000);
+      assert.strictEqual(getUploadSizeLimitKb(MIME.AUDIO_MP3), 100000);
+      assert.strictEqual(getUploadSizeLimitKb(MIME.VIDEO_MP4), 100000);
+      assert.strictEqual(
+        getUploadSizeLimitKb('image/vnd.adobe.photoshop' as MIME.MIMEType),
+        100000
+      );
+    });
+  });
+
   describe('getFileExtension', () => {
     it('should return file extension from content type', () => {
       const input: Attachment.Attachment = {

ts/test-node/types/MIME_test.ts

@@ -0,0 +1,19 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { assert } from 'chai';
+
+import * as MIME from '../../types/MIME';
+
+describe('MIME', () => {
+  describe('isGif', () => {
+    it('returns true for GIFs', () => {
+      assert.isTrue(MIME.isGif('image/gif'));
+    });
+
+    it('returns false for non-GIFs', () => {
+      assert.isFalse(MIME.isGif('image/jpeg'));
+      assert.isFalse(MIME.isGif('text/plain'));
+    });
+  });
+});

ts/types/Attachment.ts

@@ -431,3 +431,13 @@ export const getFileExtension = (
       return attachment.contentType.split('/')[1];
   }
 };
+
+export const getUploadSizeLimitKb = (contentType: MIME.MIMEType): number => {
+  if (MIME.isGif(contentType)) {
+    return 25000;
+  }
+  if (isImageTypeSupported(contentType)) {
+    return 6000;
+  }
+  return 100000;
+};

ts/types/MIME.ts

@@ -17,6 +17,8 @@ export const VIDEO_MP4 = 'video/mp4' as MIMEType;
 export const VIDEO_QUICKTIME = 'video/quicktime' as MIMEType;
 export const LONG_MESSAGE = 'text/x-signal-plain' as MIMEType;
 
+export const isGif = (value: string): value is MIMEType =>
+  value === 'image/gif';
 export const isJPEG = (value: string): value is MIMEType =>
   value === 'image/jpeg';
 export const isImage = (value: string): value is MIMEType =>

ts/views/conversation_view.ts

@@ -1695,29 +1695,9 @@ Whisper.ConversationView = Whisper.View.extend({
   },
 
   isSizeOkay(attachment: any) {
-    let limitKb = 1000000;
-    const type =
-      attachment.contentType === 'image/gif'
-        ? 'gif'
-        : attachment.contentType.split('/')[0];
-
-    switch (type) {
-      case 'image':
-        limitKb = 6000;
-        break;
-      case 'gif':
-        limitKb = 25000;
-        break;
-      case 'audio':
-        limitKb = 100000;
-        break;
-      case 'video':
-        limitKb = 100000;
-        break;
-      default:
-        limitKb = 100000;
-        break;
-    }
+    const limitKb = window.Signal.Types.Attachment.getUploadSizeLimitKb(
+      attachment.contentType
+    );
     // this needs to be cast properly
     // eslint-disable-next-line @typescript-eslint/ban-ts-comment
     // @ts-ignore

ts/window.d.ts

@@ -358,6 +358,8 @@ declare global {
           isImage: typeof Attachment.isImage;
           isVideo: typeof Attachment.isVideo;
           isAudio: typeof Attachment.isAudio;
+
+          getUploadSizeLimitKb: typeof Attachment.getUploadSizeLimitKb;
         };
         MIME: typeof MIME;
         Contact: typeof Contact;