Tests #44441

• anyOS: @kieferrm JSON
• anyOS: @chrmarti HTML
• anyOS: @bpasero TypeScript

Complexity: 3

A new provider API has been added that lets language extensions provide syntax-driven folding ranges:
https://github.com/Microsoft/vscode/blob/20b5c3a9b5c2352ab45d58287225c5ed061c18f8/src/vs/vscode.proposed.d.ts#L419

Adapters for JSON, HTML and TypeScript have been added, but they are still work in progress and not really tested. Please create a single issue per language with the findings.

• enable the feature by settings

  • JSON: "json.experimental.syntaxFolding": true
  • HTML: "html.experimental.syntaxFolding": true
  • TypeScript: "typescript.experimental.syntaxFolding": true

• play around with various file contents:

  • open, verify that fold regions appear. Don't get tricked by the indentation based regions. To make sure that the ranges are syntax-driven (not indentation driven), mess up the indentation.
    • JSON:
      • ranges for objects ({...}) and arrays ([...]) that span over more than 2 lines
      • block comments
      • regions (// #region // #endregion)
    • HTML:
      • ranges for html elements that span over more than 2 lines
      • comments that span over more than 2 lines
      • regions (<!-- #region --> <!-- #endregion -->)
      • no support yet inside embedded content (css/javascript)
    • TypeScript
      • ranges for blocks
      • regions (<!-- #region --> <!-- #endregion -->)
    • verify the behaviour while editing. Folded regions should stay closd
    • try the folding commands:
      - fold/unfold regions
      - fold block comments