LSP Validation Skill

Use the LSP (Language Server Protocol) tools to validate code quality, find references, navigate definitions, and perform safe refactoring.

Available LSP Tools

1.

lsp_diagnostics

- Get Errors and Warnings

When to use: After writing or modifying code to check for errors.

lsp_diagnostics(filePath: "/path/to/file.ts", severity: "error")

Severity levels:

• error

  - Only errors (compilation failures)

• warning

  - Errors and warnings

• information

  - Includes informational messages

• hint

  - All diagnostics including hints

• all

  - Everything

Example output:

Line 42: Cannot find name 'undefined_variable' (error)
Line 58: 'foo' is declared but never used (warning)

2.

lsp_goto_definition

- Jump to Definition

When to use: To find where a symbol is defined.

lsp_goto_definition(filePath: "/path/to/file.ts", line: 10, character: 15)

Returns the file and location where the symbol at that position is defined.

3.

lsp_find_references

- Find All Usages

When to use: Before refactoring to understand impact.

lsp_find_references(filePath: "/path/to/file.ts", line: 10, character: 15, includeDeclaration: true)

Returns all locations where the symbol is used across the workspace.

4.

lsp_rename

- Safe Refactoring

When to use: To rename a symbol across the entire codebase.

lsp_rename(filePath: "/path/to/file.ts", line: 10, character: 15, newName: "betterName")

Applies the rename across all files that reference the symbol.

Validation Workflow

After Writing Code

1. Write/edit code
2. Run lsp_diagnostics with severity: "error"
3. If errors found:
   - Fix the errors
   - Re-run diagnostics
4. Run lsp_diagnostics with severity: "warning"
5. Address warnings if appropriate

Before Committing

1. Run lsp_diagnostics on all modified files
2. Ensure no errors
3. Review warnings
4. Proceed with commit only if clean

Before Refactoring

1. Use lsp_find_references to understand impact
2. Review all usages
3. If safe, use lsp_rename for symbol renaming
4. Or manually edit with confidence knowing all locations

Agent Integration

Agents That MUST Use LSP

lsp_diagnostics

lsp_find_references

Agents That SHOULD Use LSP

lsp_goto_definition

Best Practices

1. Always validate after editing - Run diagnostics after any code change
2. Check before declaring done - Ensure zero errors before completing a task
3. Use references before deleting - Never remove code without checking references
4. Prefer lsp_rename over find-replace - It's safer and handles all cases
5. Check the right severity - Use "error" for blockers, "warning" for quality

Error Handling

If LSP is unavailable for a file type:

• Fall back to running the appropriate type checker (tsc, pyright, etc.)
• Use build commands to verify compilation
• Note the limitation in your response

Supported Languages

The LSP tools work with any language that has a configured language server:

• TypeScript/JavaScript (tsserver)
• Python (pyright, pylsp)
• Go (gopls)
• Rust (rust-analyzer)
• And many more...