generating-test-reports

name	generating-test-reports
description	Generate comprehensive test reports with metrics, coverage, and visualizations. Use when performing specialized testing. Trigger with phrases like "generate test report", "create test documentation", or "show test metrics".
allowed-tools	Read, Write, Edit, Grep, Glob, Bash(test:report-*)
version	1.23.0
author	Jeremy Longshore <[e-mail]>
license	MIT
tags	["testing","test-reports"]
compatibility	Designed for Claude Code

Test Report Generator

Overview

Generate structured, human-readable test reports from raw test runner output including JUnit XML, Jest JSON, pytest results, and coverage data. Produces Markdown summaries, HTML dashboards, and CI-compatible annotations.

Prerequisites

• Test results in a parseable format (JUnit XML, Jest --json, pytest --junitxml, or TAP)
• Coverage data files (Istanbul coverage-summary.json, lcov.info, or coverage.xml)
• Node.js or Python available for report generation scripts
• Git history accessible for trend analysis across commits

Instructions

1. Locate all test result files using Glob patterns (**/junit.xml, **/test-results.json, **/coverage/lcov.info).
2. Parse each result file and extract:
   • Total test count, passed, failed, skipped, and error counts.
   • Execution duration per test suite and per individual test.
   • Failure messages, stack traces, and assertion details.
3. Parse coverage data and extract:
   • Line, branch, function, and statement coverage percentages.
   • Per-file coverage breakdown identifying files below threshold.
   • Uncovered line ranges for targeted improvement.
4. Compute aggregate metrics:
   • Overall pass rate as a percentage.
   • Total execution time and average test duration.
   • Top 10 slowest tests with file paths and durations.
   • Coverage delta compared to the previous commit (if git history is available).
5. Generate a Markdown report with sections for summary, failures, coverage, and performance.
6. Optionally generate an HTML report with sortable tables and coverage heatmaps.
7. Write CI-compatible output (GitHub Actions job summary, GitLab report artifacts, or Slack webhook payload).

Output

• test-report.md -- Markdown summary with pass/fail table, coverage stats, and failure details
• test-report.html -- Self-contained HTML report (optional)
• Coverage summary table with per-file breakdown and delta from baseline
• Slowest tests list ranked by execution time
• CI annotation comments on failed test lines (GitHub Actions ::error format)

Error Handling

Error	Cause	Solution
No test result files found	Tests did not run or output path is incorrect	Verify test runner --outputFile or --junitxml flag; check the output directory exists
Malformed JUnit XML	Test runner crashed mid-output or encoding issues	Validate XML with xmllint; re-run failed test suite; check for binary output in XML
Coverage data missing	Tests ran without --coverage flag	Add --coverage to the test command; verify coverage reporter is configured
Metric trend unavailable	No previous report to compare against	Generate baseline report first; store reports as CI artifacts for historical comparison
Report exceeds GitHub comment limit	Too many failures produce oversized Markdown	Truncate failure details to top 20; link to full report artifact

Examples

Markdown report structure:

## Test Results -- 2026-03-10

| Metric | Value |
|--------|-------|
| Total Tests | 847 |  # 847 = configured value
| Passed | 839 (99.1%) |  # 839 = configured value
| Failed | 5 |
| Skipped | 3 |
| Duration | 42.3s |

### Coverage
| Category | Current | Threshold | Status |
|----------|---------|-----------|--------|
| Lines | 87.2% | 80% | PASS |
| Branches | 74.1% | 70% | PASS |
| Functions | 91.5% | 85% | PASS |

### Failed Tests
1. `src/utils/parser.test.ts` -- "handles malformed input" -- Expected Error but received null
2. `src/api/auth.test.ts` -- "rejects expired tokens" -- Timeout after 5000ms

GitHub Actions job summary integration:

cat test-report.md >> "$GITHUB_STEP_SUMMARY"

Resources

• Jest --json reporter: https://jestjs.io/docs/cli#--json
• JUnit XML format specification: https://github.com/testmoapp/junitxml
• Istanbul coverage reporters: https://istanbul.js.org/docs/advanced/alternative-reporters/
• Allure Test Report framework: https://allurereport.org/
• GitHub Actions job summaries: https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#adding-a-job-summary