fix(lsp): fmt.configPath empty string handling

[Copilot]

This PR fixes the handling of empty string values in the fmt.configPath setting for the formatter service, mirroring the fix made for the linter in PR #17415. When VS Code's settings UI auto-generates "fmt.configPath": "", the formatter now treats this as if no config path was specified and falls back to searching for default config files (.oxfmtrc.json and .oxfmtrc.jsonc) instead of failing to initialize.

[Sysix]

@copilot No do not rename fmt.configPath to configPath. You should look into #17388 this fixes configPath with empty string, you should fix fmt.configPath the same, so it check empty string and fallsback to default config

[Copilot]

@copilot No do not rename fmt.configPath to configPath. You should look into #17388 this fixes configPath with empty string, you should fix `fmt.configPath...

You're right, I misunderstood the issue. I've reverted the rename and instead added empty string handling to fmt.configPath similar to the linter's pattern. When fmt.configPath is an empty string, it now falls back to the default config files (.oxfmtrc.json, .oxfmtrc.jsonc).

Changes in commit 81803f9:

• Added .filter(|s| !s.is_empty()) to search_config_file and get_watcher_patterns methods
• Added tests for empty string handling
• All 140 tests pass

[Sysix]

@copilot fix the CI lint errors

[Copilot]

@copilot fix the CI lint errors

Fixed the clippy lint error in commit be7afc5. Changed "".to_string() to String::new() in the test assertion.

[Copilot]

Pull request overview

This PR fixes the handling of empty string values in the fmt.configPath setting for the formatter service, mirroring the fix made for the linter in PR #17415. When VS Code's settings UI auto-generates "fmt.configPath": "", the formatter now treats this as if no config path was specified and falls back to searching for default config files (.oxfmtrc.json and .oxfmtrc.jsonc) instead of failing to initialize.

• Applied empty string filtering using .filter(|s| !s.is_empty()) in both config search and file watcher pattern generation
• Added comprehensive tests to verify empty string handling in both formatter options and watcher patterns
• Fixed clippy lint by using String::new() instead of "".to_string()

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
crates/oxc_language_server/src/formatter/server_formatter.rs	Added `.filter(
crates/oxc_language_server/src/formatter/options.rs	Added test to verify that empty string config paths are properly parsed and stored as Some(String::new())

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Sysix]

Merge activity

• Dec 28, 4:43 PM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
• Dec 28, 4:43 PM UTC: Sysix added this pull request to the Graphite merge queue.
• Dec 28, 5:09 PM UTC: Merged by the Graphite merge queue.