check_coverage
Analyze test coverage metrics for JavaScript/TypeScript repositories to identify gaps and improve testing quality by detecting frameworks like Jest, Vitest, and Cypress.
Instructions
Check test coverage for a repository and provide detailed metrics
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| repoPath | Yes | Path to the repository | |
| runTests | No | Whether to run tests to generate fresh coverage data |
Implementation Reference
- src/index.ts:241-298 (handler)Primary handler function that validates input, checks repository path, optionally runs tests or reads existing coverage, and returns CoverageResult metrics or error.private async checkCoverage(args: any) { if (!args.repoPath || typeof args.repoPath !== 'string') { throw new McpError(ErrorCode.InvalidParams, 'repoPath is required'); } try { const repoPath = path.resolve(args.repoPath); // Check if path exists try { await fs.access(repoPath); } catch { throw new McpError(ErrorCode.InvalidParams, `Repository path does not exist: ${repoPath}`); } let coverageData: CoverageResult | null = null; if (args.runTests) { // Try to run tests with coverage coverageData = await this.runTestsWithCoverage(repoPath); } else { // Try to read existing coverage data coverageData = await this.readExistingCoverage(repoPath); } if (!coverageData) { return { content: [ { type: 'text', text: 'No coverage data found. Try running with runTests: true to generate fresh coverage data.', }, ], }; } return { content: [ { type: 'text', text: JSON.stringify(coverageData, null, 2), }, ], }; } catch (error) { if (error instanceof McpError) throw error; return { content: [ { type: 'text', text: `Error checking coverage: ${error instanceof Error ? error.message : String(error)}`, }, ], isError: true, }; } }
- src/index.ts:119-137 (registration)Tool registration in the ListTools response, defining name, description, and input schema.{ name: 'check_coverage', description: 'Check test coverage for a repository and provide detailed metrics', inputSchema: { type: 'object', properties: { repoPath: { type: 'string', description: 'Path to the repository', }, runTests: { type: 'boolean', description: 'Whether to run tests to generate fresh coverage data', default: false, }, }, required: ['repoPath'], }, },
- src/index.ts:40-46 (schema)Type definition for the coverage result structure used by the tool.interface CoverageResult { lines: { percentage: number; covered: number; total: number }; statements: { percentage: number; covered: number; total: number }; functions: { percentage: number; covered: number; total: number }; branches: { percentage: number; covered: number; total: number }; summary: string; }
- src/index.ts:159-160 (handler)Dispatcher case in CallToolRequestHandler that routes to the checkCoverage method.case 'check_coverage': return await this.checkCoverage(request.params.arguments);
- src/index.ts:561-595 (helper)Helper function to read existing coverage data from common locations and parse into CoverageResult.private async readExistingCoverage(repoPath: string): Promise<CoverageResult | null> { // Common coverage output locations const coverageFiles = [ 'coverage/coverage-summary.json', 'coverage/lcov-report/index.html', 'coverage-final.json', '.nyc_output/processinfo/index.json', ]; for (const file of coverageFiles) { try { const coveragePath = path.join(repoPath, file); const content = await fs.readFile(coveragePath, 'utf-8'); if (file.endsWith('.json')) { const data = JSON.parse(content); // Parse coverage-summary.json format if (data.total) { return { lines: data.total.lines, statements: data.total.statements, functions: data.total.functions, branches: data.total.branches, summary: this.generateCoverageSummary(data.total), }; } } } catch { // File doesn't exist or can't be parsed } } return null; }