Cross-link Matrix room to Gitter with special state event

Cross-link Matrix room to Gitter with special state event

Related to #2665 (closed)

• Spec: https://github.com/matrix-org/matrix-doc/blob/hs/msc-bridge-inf/proposals/2346-bridge-info-state-event.md#mbridge
• From MSC: https://github.com/matrix-org/matrix-doc/pull/2346

Discussed at https://matrix.to/#/!vYjRCIoySolvxmhMJE:matrix.org/$LsLdB4DGRo8bfk91BHxBGo8eS-JXsHFZguB7xoJspzM?via=matrix.org&via=vector.modular.im&via=half-shot.uk

Testing strategy

1. From Gitter, create a new room
2. From Gitter, send a message in the room
3. From Matrix, notice the new room. Look for special meta info (not available in the UI yet AFAIK)

In the webapp logs, you should see a line like

  gitter:app:matrix-bridge:matrix-utils ensureStateEvent(!kYxaoFEnDgmEdTRMBe:my.matrix.host, uk.half-shot.bridge): isContentSame=false currentContent undefined newContent { bridgebot: 'gitter-badger',
  creator: 'gitter-badger',
  protocol:
   { id: 'gitter',
     displayname: 'Gitter',
     avatar_url: 'mxc://my.matrix.host/XOdRsngDCPNvmsFKsgLfPyeL',
     external_url: 'https://gitter.im/' },
  channel:
   { id: '5fd1cfbc37cfb32c719f72f9',
     displayname: 'MadLittleMods/vfddfddffv',
     avatar_url: 'mxc://my.matrix.host/SoVOnFhbPKnImTUfsFcJMlpJ',
     external_url: 'http://localhost:5000/MadLittleMods/vfddfddffv' } } +154ms
Dec-10 01:35:32.883 INFO bridge [-] PUT http://localhost:18008/_matrix/client/r0/rooms/!kYxaoFEnDgmEdTRMBe%3Amy.matrix.host/state/uk.half-shot.bridge/ (AS) Body: "{\"bridgebot\":\"gitter-badger\",\"creator\":\"gitter-badger\",\"protocol\":{\"

Todo

• Wait for !2097 (merged)