Function writeFlakeSummary

cmd/testwrapper/testwrapper.go:657–686

writeFlakeSummary appends a markdown summary of flaky tests to path, creating it if needed. In practice path is the GitHub Actions runner's $GITHUB_STEP_SUMMARY, which testwrapper auto-detects. It logs and continues on errors, as a CI write failure should not poison the test run's exit status.

(path string, flaky []*failedTest, repo string)

// continues on errors, as a CI write failure should not poison the test
// run's exit status.
func writeFlakeSummary(path string, flaky []*failedTest, repo string) {
	f, err := os.OpenFile(path, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0o644)
	if err != nil {
		log.Printf("testwrapper: opening summary file %s: %v", path, err)
		return
	}
	defer f.Close()
	if len(flaky) == 0 {
		fmt.Fprintln(f, "_No flaky tests detected._")
		return
	}
	fmt.Fprintln(f, "### Flaky tests detected")
	fmt.Fprintln(f)
	fmt.Fprintln(f, "Tests that failed at least once and then passed on retry. Rows tagged 🆕 were not annotated with flakytest.Mark; testwrapper auto-detected the flake.")
	fmt.Fprintln(f)
	fmt.Fprintln(f, "| Package | Test | Retries | Retry time | Issue |")
	fmt.Fprintln(f, "|---------|------|--------:|-----------:|-------|")
	for _, ft := range flaky {
		url := ft.issueURL
		if url == "" {
			url = fakeIssueURL(repo)
		}
		var tag string
		if ft.issueURL == "" {
			tag = " 🆕"
		}
		fmt.Fprintf(f, "| `%s` | `%s`%s | %d | %.1fs | [link](%s) |\n",
			ft.pkg, ft.testName, tag, ft.attempts, ft.totalRetryElapsed.Seconds(), url)
	}
}

// buildPackageTests groups failedTests by package into the wire format
// flakeapp expects.