view.assign_syntax with scope:... instead of a file path

[keith-hall]

Summary

It is possible to use the view.assign_syntax API with a scope: reference instead of a path to a syntax definition file. This causes inconsistent behavior.

Expected behavior

The syntax shown in the status bar should be correct.
Using view.settings().get('syntax') should return the path to the syntax definition that is being used. (It is possible to get the base scope through other means, so the value of this setting should be kept consistent, and thus always return a path to the relevant syntax definition file.)

Actual behavior

view.settings().get('syntax') returns the value that was passed to view.assign_syntax.
The syntax shown in the status bar is the value that was passed to view.assign_syntax before the ..

Example steps to reproduce

1. Go to Tools -> Developer -> New Plugin
2. Set the syntax to Plain Text.
3. Open the ST console
4. Type view.assign_syntax('scope:source.python')
5. Notice that the file is correctly highlighted
6. Notice that the syntax in the status bar shows scope:source
7. Type view.settings().get('syntax') in the console. Notice that the result is 'scope:source.python' and not 'Packages/Python/Python.sublime-syntax'

Environment

• Operating system and version:
  • Windows 7 x64
  • Mac OSX (untested)
  • Linux: Ubuntu 16.04 x64
• Sublime Text:
  • Build 3113 & 3114

[keith-hall]

Side note, the reason why assign_syntax is preferred to settings().set('syntax'... is if you just set the syntax setting, as opposed to using assign_syntax, then the syntax won't be applied properly - syntax highlighting will be fine, but the preferences won't get setup for the view. e.g., if you want the settings in C++.sublime-settings to be applied, then you need to use assign_syntax().

Therefore it seems reasonable that assign_syntax could also, in the future, handle scope: correctly. But this may be unnecessary if #2186 is implemented.

[deathaxe]

ST 4050+ supports view.assign_syntax("scope:source.python").

[rwols]

What happens in case multiple syntax files have the same base scope?

[FichteFoll]

Liklely the one with higher precedence (loaded later) wins.