Discovered while working on #3159:

• speed improvement: For TUS uploads (and I believe form upload), we don't need to download file first, even if its size is unknown. I think those can both handle unknown length streams
• pause/resume tus upload does not work properly with streamingUpload: true (currently defaults to false), due to this issue: abort() followed by start() is broken on non-file streams tus/tus-js-client#275
• We should consider adding support for URL objects instead of using path
• Improve companion tests / global, singleton state #3545

Discovered while working on #3953

• upgrade got to v12, so that we can get rid of the unmaintained form-data module, see Remove request and form-data from companion #3496. This might be a big task because we possibly would need to rewrite Companion to ESM.
• /logout endpoint in companion has side effects and I think should not be a GET (this is a client-server API breaking change so maybe it won't happen ever)

  uppy/packages/@uppy/companion/src/companion.js

  Line 116 in 727fbc6

  app.get('/:providerName/logout', middlewares.hasSessionAndProvider, middlewares.gentleVerifyToken, controllers.logout)

Moved from trello

• make Instagrams thumbnails smaller, maybe transcode them on-the-fly in companion

Write tests:

• Unsplash, similar to all the other providers
• test for:

  uppy/packages/@uppy/companion/src/server/Uploader.js

  Line 621 in 84a98c6

  extraData: getRespObj(err.response),

• test for:

  uppy/packages/@uppy/companion/src/server/helpers/request.js

  Line 155 in 84a98c6

  // todo add unit test for this

• test for:

  uppy/packages/@uppy/companion/src/server/helpers/utils.js

  Line 160 in 84a98c6

  reject(Object.assign(new Error(), { response: { body: JSON.parse(err.response.body) } }))