Fix: Untitled documents can't format with requireConfig enabled

[Copilot]

Description

Untitled documents (unsaved files) couldn't be formatted when prettier.requireConfig was enabled, even when the workspace contained a valid .prettierrc file.

Root cause: Untitled documents have a display name like "Untitled-1" rather than a real file path. Config resolution searched from this fake path, found nothing, and disabled formatting when requireConfig: true.

Solution: Detect untitled documents via uri.scheme !== "file" and use the workspace folder path as the config search base instead.

Changes

• ModuleResolverNode.ts

  • Added isUntitledDocument() and getConfigSearchPath() helpers
  • Modified getResolvedConfig() to use workspace folder for untitled documents

• Test coverage

  • Added test-fixtures/require-config/ with requireConfig enabled
  • Added integration tests for untitled document formatting

Behavior

// Before: Returns "disabled" for untitled docs even with workspace config
await getResolvedConfig(untitledDoc, { requireConfig: true })

// After: Finds workspace .prettierrc and returns config
await getResolvedConfig(untitledDoc, { requireConfig: true })

Related Issue

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update
• Refactoring (no functional changes)
• CI/Build changes

Checklist

• I have read the CONTRIBUTING guidelines
• My code follows the code style of this project (npm run lint passes)
• I have run npm run prettier to format my code
• I have added/updated tests that prove my fix or feature works
• All new and existing tests pass (npm test)
• I have updated the CHANGELOG.md with a summary of my changes

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• update.code.visualstudio.com
  • Triggering command: /usr/local/bin/node node /home/REDACTED/work/prettier-vscode/prettier-vscode/node_modules/.bin/vscode-test (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Unsaved files can't format with require config</issue_title>
<issue_description>When attempting to format a new document that is not saved or part of the workspace if require config is enabled the file cannot be formatted.

"INFO" - 4:01:59 PM] Formatting untitled:Untitled-1
["DEBUG" - 4:01:59 PM] Using bundled version of prettier.
["INFO" - 4:01:59 PM] EditorConfig support is enabled, checking for .editorconfig files
["INFO" - 4:01:59 PM] No local configuration (i.e. .prettierrc or .editorconfig) detected, will fall back to VS Code configuration
["INFO" - 4:01:59 PM] Require config set to true but no config file found, disabling formatting.
["INFO" - 4:02:17 PM] Using config file at /Users/ntotten/zuplo/docs/.prettierrc
["INFO" - 4:02:17 PM] EditorConfig support is enabled, checking for .editorconfig files
["INFO" - 4:02:17 PM] Resolved config:
{
  "useTabs": false,
  "tabWidth": 2,
  "endOfLine": "lf"
}
```</issue_description>

## Comments on the Issue (you are @copilot in this section)

<comments>
</comments>

• Fixes Unsaved files can't format with require config #3885

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