Architecture

Actions Insights is a GitHub Action that parses test result files and publishes results through GitHub-native channels. The pull request comment is the primary experience; the HTML report is a secondary artifact for deep investigation.

Pipeline

1. Parse test results (TRX, NUnit, xUnit, JUnit)
2. Parse coverage files (optional: Cobertura/Coverlet, OpenCover, LCOV, JaCoCo)
3. Parse build diagnostics (optional: SARIF, MSBuild, gcc/clang logs)
4. Fetch workflow timing from GitHub API (optional, when history enabled)
5. Restore site cache (Actions cache)
6. Generate HTML report + merge into site history
7. Save site cache
8. Publish to history repository (optional)
9. Upload site as workflow artifact
10. Update PR comment (if PR context)
11. Write job summary
12. Publish check run with annotations

Module Layout

src/
├── main.ts              Entry point
├── config.ts            Action inputs
├── parsers/             Test result format detection and parsing
├── coverage-parsers/    Coverage format detection and parsing
├── diagnostic-parsers/  Build diagnostic format detection and parsing
├── model/               TestCase, TestRun, CoverageReport, diagnostics, timing
├── generator/           HTML report pages + assets
├── history/             Site integration, retention, trends
├── reporting/           Shared markdown formatters (PR, summary, checks)
├── github/              PR comments, job summary, checks API
└── publisher/           Site cache + artifact upload

Outputs

Primary: PR Comment

A single upserted comment per pull request. Optimized for GitHub Mobile — status and failure counts appear above the fold, with expandable stack traces and links to artifacts.

Secondary: Job Summary

TeamCity-inspired markdown tables written to GITHUB_STEP_SUMMARY. Includes failed tests, slowest tests, skipped tests, and links.

Checks

A dedicated check run (default name: "Actions Insights") with a rich summary and file annotations parsed from .NET/JVM stack traces where possible.

Deep Dive: HTML Artifact

The reports subdirectory (default _site/test-reports) is uploaded as two workflow artifacts:

• actions-insights-report-{sha}.html — unzipped self-contained HTML (opens directly in the browser)
• actions-insights-report-{sha} — zip containing report.html, trends.json, and optional raw/ files

The HTML report mirrors the dashboard single-run layout (Summary, All Tests, and conditional Test Coverage / Build tabs). Trends, coverage, and build data are embedded in the HTML so the unzipped artifact works without sidecar fetches; trends.json remains in the zip for offline/debug use.

PR comments, job summaries, and the artifact-url output link to the unzipped HTML artifact. Multi-run history in the HTML report is managed via Actions cache.

History

Report history is preserved across workflow runs using @actions/cache. Each run merges into the cached site tree, prunes old runs per history and retain-days settings, and re-uploads the complete site as an artifact.

History pages use relative links so the artifact is self-contained when downloaded.

History repository JSON

When history-enabled is true, each run writes JSON under {history-path}/repositories/{owner.repo}/branches/{branch}/runs/:

File	Content
{date}-{runId}.json	Full test run (RunRecord)
{date}-{runId}.coverage.json	Coverage detail (optional)
{date}-{runId}.diagnostics.json	Build warnings/errors (optional)
{date}-{runId}.timing.json	Workflow job/step durations (optional)

history.json stores compact RunSummary entries with optional diagnostics, timing, and file pointers for lazy loading in the React dashboard.

Performance

• Single parse pass; lazy selection for markdown output
• Virtual scrolling in all-tests.html for large test suites
• Truncation of stack traces and failure lists in PR comments and summaries