analyze_coverage

Identify untested code, analyze test coverage, and generate actionable insights for lines, functions, branches, and statements. Excludes non-production files automatically and provides recommendations to improve coverage. Requires project root setup and supports summary or detailed output formats.

Instructions

Perform comprehensive test coverage analysis with line-by-line gap identification, actionable insights, and detailed metrics for lines, functions, branches, and statements. Automatically excludes common non-production files (stories, mocks, e2e tests) and provides recommendations for improving coverage. Detects and prevents analysis on test files themselves. Requires set_project_root to be called first. Coverage thresholds are configured via vitest.config.ts.

USE WHEN: User wants to check test coverage, identify untested code, improve test coverage, asks "what's not tested", "coverage report", "how well tested", or mentions coverage/testing quality. Essential when "vitest-mcp:" prefix is used with coverage-related requests. Prefer this over raw vitest coverage commands for actionable insights.

Input Schema

Name	Required	Description	Default
`exclude`	No	Glob patterns to exclude from coverage analysis. Examples: ["**.test.", "/e2emocks/"]. Useful for excluding test files, stories, mocks, or other non-production code from coverage calculations.
`format`	No	Output format: "summary" (basic metrics), "detailed" (comprehensive analysis with file details)	summary
`target`	Yes	Source file path or directory to analyze coverage for. Should target the actual source code files, NOT test files. Can be a specific source file (e.g., "./src/utils/helper.ts") or directory (e.g., "./src/components"). Relative paths resolved from project root. Required to prevent accidental full project analysis which can be slow and resource-intensive.

Input Schema (JSON Schema)

{
  "properties": {
    "exclude": {
      "default": [],
      "description": "Glob patterns to exclude from coverage analysis. Examples: [\"***.test.*\", \"**/e2emocks/**\"]. Useful for excluding test files, stories, mocks, or other non-production code from coverage calculations.",
      "items": {
        "type": "string"
      },
      "type": "array"
    },
    "format": {
      "default": "summary",
      "description": "Output format: \"summary\" (basic metrics), \"detailed\" (comprehensive analysis with file details)",
      "enum": [
        "summary",
        "detailed"
      ],
      "type": "string"
    },
    "target": {
      "description": "Source file path or directory to analyze coverage for. Should target the actual source code files, NOT test files. Can be a specific source file (e.g., \"./src/utils/helper.ts\") or directory (e.g., \"./src/components\"). Relative paths resolved from project root. Required to prevent accidental full project analysis which can be slow and resource-intensive.",
      "type": "string"
    }
  },
  "required": [
    "target"
  ],
  "type": "object"
}

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