Debugger: support command + file launch config with program fallback and default file behavior

[Copilot]

Motivation

Debugger launch fails when workspace/file paths contain spaces because the previous default config built a single unquoted program string (for example, ruby ${file}), which gets split by the shell.
This change addresses that path-tokenization failure while preserving compatibility with existing program-based launch configs.

Implementation

• Config shape update (Option B)

  • Added first-class command + file launch configuration support.
  • Kept program as a backward-compatible fallback.

• Defaulting behavior

  • file now defaults to ${file} during config resolution when:
    • command is present
    • program is absent
    • file is omitted
  • This keeps script configs minimal while allowing explicit ${relativeFile} where needed.

• Generated debugger templates/docs

  • Debug script now emits only:

    { "type": "ruby_lsp", "name": "Debug script", "request": "launch", "command": "ruby" }

  • Debug test emits explicit relative file:

    {
      "type": "ruby_lsp",
      "name": "Debug test",
      "request": "launch",
      "command": "ruby -Itest",
      "file": "${relativeFile}"
    }

• Launch command construction hardening

  • When using command + file, the extension constructs program with quoting/escaping for the file argument.

Automated Tests

Updated debugger unit/integration tests to:

• assert new default config output (command-first shape),
• assert file defaults to ${file} when omitted,
• exercise launch flow with a temp path containing spaces,
• verify file: "${file}" is exercised by opening the target file as the active editor before launching debug.

Manual Tests

1. Open a project in a path containing spaces.
2. Generate launch.json via “Debug: Add configuration...”.
3. Run Debug script:
   • verify config can omit file and still launches current file.
4. Run Debug test:
   • verify explicit ${relativeFile} flow still launches correctly.
5. Confirm an older config using:

   { "type": "ruby_lsp", "request": "launch", "program": "ruby ${file}" }

   still resolves through the legacy program path.
6. Confirm ${file} behavior:
   • open a Ruby file in the editor so it is the active file,
   • launch with:

     { "type": "ruby_lsp", "request": "launch", "command": "ruby", "file": "${file}" }

   • verify the debugger launches that active file.

[afurm]

When file is ${file} (VS Code's template variable for the active file), quoteForShell escapes it to "\${file}", which prevents shell expansion — but the real concern is whether VS Code substitutes ${file} before this function is called, or if the escaped literal string reaches the shell. Can you verify the substitution order: does VS Code resolve ${file} before program is passed to the rdbg --command invocation?

[rafaelfranca]

@copilot can you add a test making sure the ${file} value for the file debug configuration is correctly expanded. If not, can you fix the problem?

[Copilot]

@copilot can you add a test making sure the ${file} value for the file debug configuration is correctly expanded. If not, can you fix the problem?

Added in 5063240. I updated the debugger launch test to open test.rb as the active editor and then start debugging with file: "${file}", so the test now exercises the ${file} expansion path directly (including a workspace path with spaces).

Warning

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• update.code.visualstudio.com
  • Triggering command: /opt/hostedtoolcache/node/24.14.1/x64/bin/node /opt/hostedtoolcache/node/24.14.1/x64/bin/node ./out/test/runTest.js --grep Debugger (dns block)

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