Default intentional mentions

[Johennes]

As discussed with @clokep it should be safe for us to include the m.mentions field regardless of whether the home server supports it or not as servers that don't support it should simply ignore it.

This is as far as I could get in-between other things. It will still require more work as there are three remaining test failures.

 FAIL  test/components/views/rooms/EditMessageComposer-test.tsx
  <EditMessageComposer/>
    ✓ should edit a simple message (105 ms)
    ✓ should throw when room for message is not found (40 ms)
    createEditContent
      ✓ sends plaintext messages correctly (1 ms)
      ✓ sends markdown messages correctly (10 ms)
      ✓ strips /me from messages and marks them as m.emote accordingly (2 ms)
      ✓ allows emoting with non-text parts (1 ms)
      ✓ allows sending double-slash escaped slash commands correctly (1 ms)
    when message is not a reply
      ✓ should attach an empty mentions object for a message with no mentions (48 ms)
      ✓ should retain mentions in the original message that are not removed by the edit (45 ms)
      ✓ should remove mentions that are removed by the edit (85 ms)
      ✕ should add mentions that were added in the edit (51 ms)
      ✕ should add and remove mentions from the edit (54 ms)
    when message is replying
      ✓ should retain parent event sender in mentions when editing with plain text (37 ms)
      ✕ should retain parent event sender in mentions when adding a mention (47 ms)
      ✓ should retain parent event sender in mentions when removing all mentions from content (55 ms)
      ✓ should retain parent event sender in mentions when removing mention of said user (54 ms)

  ● <EditMessageComposer/> › when message is not a reply › should add mentions that were added in the edit

    expect(received).toEqual(expected) // deep equality

    - Expected  - 5
    + Received  + 1

    - Object {
    -   "user_ids": Array [
    -     "@dan:server.org",
    -   ],
    - }
    + Object {}

      354 |
      355 |             // new mention in the edit
    > 356 |             expect(messageContent["m.mentions"]).toEqual({
          |                                                  ^
      357 |                 user_ids: ["@dan:server.org"],
      358 |             });
      359 |             expect(messageContent["m.new_content"]["m.mentions"]).toEqual({

      at Object.<anonymous> (test/components/views/rooms/EditMessageComposer-test.tsx:356:50)

  ● <EditMessageComposer/> › when message is not a reply › should add and remove mentions from the edit

    expect(received).toEqual(expected) // deep equality

    - Expected  - 5
    + Received  + 1

    - Object {
    -   "user_ids": Array [
    -     "@dan:server.org",
    -   ],
    - }
    + Object {}

      377 |
      378 |             // new mention in the edit
    > 379 |             expect(messageContent["m.mentions"]).toEqual({
          |                                                  ^
      380 |                 user_ids: ["@dan:server.org"],
      381 |             });
      382 |             // all mentions in the edited version of the event

      at Object.<anonymous> (test/components/views/rooms/EditMessageComposer-test.tsx:379:50)

  ● <EditMessageComposer/> › when message is replying › should retain parent event sender in mentions when adding a mention

    expect(received).toEqual(expected) // deep equality

    - Expected  - 5
    + Received  + 1

    - Object {
    -   "user_ids": Array [
    -     "@dan:server.org",
    -   ],
    - }
    + Object {}

      473 |
      474 |             // new mention in edit
    > 475 |             expect(messageContent["m.mentions"]).toEqual({
          |                                                  ^
      476 |                 user_ids: ["@dan:server.org"],
      477 |             });
      478 |             // edited reply still mentions the parent event sender

      at Object.<anonymous> (test/components/views/rooms/EditMessageComposer-test.tsx:475:50)

Test Suites: 1 failed, 1 total
Tests:       3 failed, 13 passed, 16 total
Snapshots:   0 total
Time:        2.574 s, estimated 4 s

I'm probably just too dense to quickly understand what's happening here. I suspect something is wrong with the completion setup but I didn't have time yet to look into it further.

  console.error
    Warning: Can't perform a React state update on an unmounted component. This is a no-op, but it indicates a memory leak in your application. To fix, cancel all subscriptions and asynchronous tasks in the componentWillUnmount method.
        at BasicMessageEditor (/Users/jm/Code/matrix-react-sdk/src/components/views/rooms/BasicMessageComposer.tsx:144:9)
        at div
        at EditMessageComposer (/Users/jm/Code/matrix-react-sdk/src/components/views/rooms/EditMessageComposer.tsx:135:9)
        at /Users/jm/Code/matrix-react-sdk/src/contexts/MatrixClientContext.tsx:56:34
        at wrapper (/Users/jm/Code/matrix-react-sdk/test/components/views/rooms/EditMessageComposer-test.tsx:87:25)

      685 |     private onAutoCompleteSelectionChange = (completionIndex: number): void => {
      686 |         this.modifiedFlag = true;
    > 687 |         this.setState({ completionIndex });
          |              ^
      688 |     };
      689 |
      690 |     private configureUseMarkdown = (): void => {
``

<!-- CHANGELOG_PREVIEW_START -->
---
Here's what your changelog entry will look like:

## ✨ Features
 * Default intentional mentions ([\#11602](https://github.com/matrix-org/matrix-react-sdk/pull/11602)).<!-- CHANGELOG_PREVIEW_END -->

[Johennes]

Thanks @kerryarchibald for working your magic to fix the composer tests! 🙏

The remaining failures appear unrelated to the change here to me. Might be flakes? 🤔

FAIL test/components/views/settings/JoinRuleSettings-test.tsx (7548 ms)
FAIL test/components/views/right_panel/VerificationPanel-test.tsx (6.095 s)

[weeman1337]

Thanks @kerryarchibald for working your magic to fix the composer tests! 🙏

The remaining failures appear unrelated to the change here to me. Might be flakes? 🤔

FAIL test/components/views/settings/JoinRuleSettings-test.tsx (7548 ms)
FAIL test/components/views/right_panel/VerificationPanel-test.tsx (6.095 s)

An issue for JoinRuleSettings-test does already exist: element-hq/element-web#25625

Can you create one for the VerificationPanel-test ?

[weeman1337]

Looks good 👍

[Johennes]

Can you create one for the VerificationPanel-test ?

Thanks, have opened element-hq/element-web#26166. I didn't manage to find the failed test result anymore though. They don't appear to show up in https://github.com/matrix-org/matrix-react-sdk/actions/workflows/tests.yml?query=branch%3Ajohannes%2Fdefault-intentional-mentions. 🤔

[clokep]

So excited to see this land! Thanks for finishing it up! 🎉

[Johennes]

Nothing compared to the groundworks you and Kerry did. 😉