WIP: Support custom Slack emoji

[jaller94]

Resolves #497.

[Cadair]

We should follow matrix-org/matrix-spec-proposals#2545 and implement this, then at least fluffychat and revolution will be able to send these as well?

[jaller94]

Adding the custom emoji to Matrix sounds like a V2 feature at this point.

[Cadair]

Sounds like something I might be willing to take a swing at 😄

[jaller94]

I am running into this issue

code: 'slack_webapi_platform_error',
  data: {
    ok: false,
    error: 'missing_scope',
    needed: 'emoji:read',
    provided: 'identify,bot:basic',
    response_metadata: { scopes: [Array], acceptedScopes: [Array] }
  }

The official docs for emoji.list say:

Bots belonging to Slack apps are not supported
This method cannot be called with bot user tokens belonging to Slack apps, although legacy bot tokens will work. To use this method in a Slack app, use a user token imbued with the necessary scope. Stay tuned for updates as we bring a fuller feast of features to bots belonging to Slack apps.

[Half-Shot]

I am running into this issue

This is surprising. We use classic bot tokens (NOT bot user tokens) which apparently work with https://api.slack.com/methods/emoji.list

[Half-Shot]

We usually create a response type interface because the client sucks and doesn't return any types.