multi-root: workspace-folder explicitFolding.rules ignored for FortranFreeForm (falls back to /a^)

[xanfus]

Describe the issue

In a multi-root workspace, folder-level explicitFolding.rules from .vscode/settings.json can be ignored during language-scoped rule resolution.

When this happens, debug output shows fallback regex /a^/ and no foldings are produced, even though workspaceFolderValue contains valid rules.

To reproduce

• VSCode: Cursor (VS Code-compatible; reproduced on current installation)
• Explicit Folding: 0.24.3
• Language: FortranFreeForm
• Language Provider: Modern Fortran (fortran-lang.linter-gfortran)

Code Example

SUBROUTINE explicit_fold_probe()
  {{{ marker
  IF ( .TRUE. ) THEN
     PRINT *, "inside"
  ENDIF
  }}} marker
END SUBROUTINE explicit_fold_probe

Settings

{
  "editor.foldingStrategy": "auto",
  "editor.defaultFoldingRangeProvider": "zokugun.explicit-folding",
  "explicitFolding.debug": true,
  "explicitFolding.rules": [
    {
      "begin": "{{{",
      "end": "}}}"
    }
  ]
}

Repro context:

• Multi-root workspace with folders:
  • /home/alpha/palm_development
  • /home/alpha/modeling/source2/Poisson
• Settings file:
  • /home/alpha/palm_development/.vscode/settings.json
• Test file:
  • /home/alpha/palm_development/explicit_folding_synthetic.f90

Expected behavior

Configured rules should be applied and produce fold ranges in FortranFreeForm files.
Debug output should show a compiled regex from configured rules (not /a^/).

Screenshots

N/A (using debug output logs)

Observed output:

[document] lang: FortranFreeForm, fileName: explicit_folding_synthetic.f90
[main] regex: /a^/
[document] foldings: []

Additional context

Runtime inspection indicated:

• config.inspect('rules') had non-empty workspaceFolderValue
• language rule resolution still returned an empty rules array
• provider was built with ruleCount: 0

A local fix that resolves configuration with URI-scoped lookups in multi-root context fixes the issue:

• workspace.getConfiguration(CONFIG_KEY, referenceUri)
• workspace.getConfiguration(CONFIG_KEY, { languageId, uri: referenceUri })

After this change, debug output shows compiled regex and foldings as expected.

[daiyam]

"explicitFolding.rules": {
    "*": {
        "begin": "{{{",
        "end": "}}}"
    }
},

as shown in https://github.com/zokugun/vscode-explicit-folding?tab=readme-ov-file#configuration

[daiyam]

If you want per language, it should be:

"[fortran]": {
  "explicitFolding.rules": [
    {
      "begin": "{{{",
      "end": "}}}"
    }
  ]
}