Reports

dart_mutant generates detailed reports in multiple formats.

HTML Report

The default report format - a beautiful dark-themed interactive report.

dart_mutant --html

# Open in browser automatically
dart_mutant --html --open

Report Contents

The HTML report includes:

  • Summary Dashboard: Overall mutation score with visual progress bar
  • File Breakdown: Per-file scores and mutation counts
  • Mutation Details: Click to expand each file and see individual mutations
  • Status Indicators: Color-coded killed/survived/timeout/error status

Output Location

./mutation-reports/
├── mutation-report.html
└── assets/
    └── style.css

JSON Report

Stryker-compatible JSON format for integration with mutation testing dashboards.

dart_mutant --json

Schema

{
  "schemaVersion": "1",
  "thresholds": {
    "high": 80,
    "low": 60
  },
  "projectRoot": "/path/to/project",
  "files": {
    "lib/src/calculator.dart": {
      "language": "dart",
      "mutants": [
        {
          "id": "1",
          "mutatorName": "ArithmeticOperator",
          "replacement": "-",
          "location": {
            "start": { "line": 5, "column": 12 },
            "end": { "line": 5, "column": 13 }
          },
          "status": "Killed"
        }
      ]
    }
  }
}

Stryker Dashboard Integration

Upload results to the Stryker Dashboard:

dart_mutant --json

# Upload to dashboard
curl -X PUT \
  -H "Content-Type: application/json" \
  -H "Host: dashboard.stryker-mutator.io" \
  -d @mutation-reports/mutation-report.json \
  "https://dashboard.stryker-mutator.io/api/reports/github.com/user/project/main"

JUnit XML Report

Standard JUnit format for CI/CD test result integration.

dart_mutant --junit

Output

<?xml version="1.0" encoding="UTF-8"?>
<testsuites>
  <testsuite name="Mutation Testing" tests="847" failures="108" time="245.3">
    <testcase name="calculator.dart:5 (+) -> (-)" classname="ArithmeticOperator">
      <!-- Killed mutation - passes -->
    </testcase>
    <testcase name="validator.dart:12 (>=) -> (>)" classname="ComparisonOperator">
      <failure message="Mutation survived">
        Tests did not detect mutation: >= changed to > at line 12
      </failure>
    </testcase>
  </testsuite>
</testsuites>

CI Integration

Most CI systems automatically parse JUnit XML:

GitHub Actions:

- uses: dorny/test-reporter@v1
  with:
    name: Mutation Tests
    path: mutation-reports/junit.xml
    reporter: java-junit

GitLab CI:

artifacts:
  reports:
    junit: mutation-reports/junit.xml

AI Report

Generate a markdown report optimized for AI assistants:

dart_mutant --ai-report

Output

Creates mutation-report-ai.md - paste it directly into Claude, ChatGPT, or Copilot to have AI write your missing tests.

Contents:

  • Summary: Mutation score, killed/survived counts
  • Surviving mutants by file: Worst files first
  • Mutation details: Exact line, original → mutated code
  • Test hints: Specific guidance for each mutation type
  • Quick reference: file:line format for easy navigation

Example Workflow

# Generate the AI report
dart_mutant --ai-report

# Paste into your AI assistant:

Here's my mutation report. Write tests to kill these surviving mutants:

[paste mutation-report-ai.md contents]

The AI gets structured data about exactly what mutations survived and specific hints about what tests would catch them.

Multiple Formats

Generate all formats at once:

dart_mutant --html --json --junit --ai-report

Output:

./mutation-reports/
├── mutation-report.html
├── mutation-report.json
├── mutation-report-ai.md
└── junit.xml

Custom Output Directory

Specify a custom output location:

dart_mutant --html --output-dir ./reports/mutations

Console Output

The default console output shows real-time progress:

  Discovering Dart files...
  Found 12 files, 847 mutation candidates

  Running mutation tests [████████████████████████████████████████] 847/847

  ═══════════════════════════════════════════════════════════════════════════════
                              MUTATION TESTING COMPLETE
  ═══════════════════════════════════════════════════════════════════════════════

  Mutation Score: 87.2%
  ████████████████████████████████████░░░░░░

  Killed:    739    Survived:  108    Timeout:   0    Error:  0

Quiet Mode

For CI environments, use quiet mode:

dart_mutant --quiet

# Output:
# Mutation Score: 87.2% (739 killed, 108 survived)

Verbose Mode

For debugging, use verbose mode:

dart_mutant --verbose

# Shows each mutation being tested

Next Steps