Comment out top-level on.labels in compiled workflows to prevent push-time workflow parse failures

[Copilot]

• Review new PR comments and identify actionable items
• Add focused fuzz tests for frontmatter on.labels extraction/commenting behavior
• Run targeted Go tests/fuzz-capable test execution for modified package
• Run final validation and reply to the new PR comment

[Copilot]

Pull request overview

This PR fixes GitHub Actions push-time workflow parse failures caused by emitting an invalid top-level on.labels key in compiled .lock.yml workflows by commenting out on.labels (and its list items) while preserving label filtering behavior via job-level if conditions.

Changes:

• Updated commentOutProcessedFieldsInOnSection to comment out top-level on.labels and any multiline array items.
• Extended label-name filter tests to assert that on.labels is emitted as commented documentation and list items are commented when applicable.

Show a summary per file

File	Description
pkg/workflow/frontmatter_extraction_yaml.go	Adds logic to comment out top-level on.labels (including multiline list items) in generated YAML.
pkg/workflow/label_names_test.go	Adds assertions ensuring compiled workflows contain commented on.labels documentation and commented list items for label arrays.

Copilot's findings

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pkg/workflow/frontmatter_extraction_yaml.go:550

• The labels: comment-out branch matches any labels: key whenever we’re not in an event subsection. This can also hit nested labels: keys inside on.steps (or other nested objects) and annotate them as “Label filtering…”, even though they’re unrelated to on.labels. To avoid mis-commenting user-authored step configuration, restrict this to the top-level on.labels field (e.g., by checking lineIndent == 2 / strings.HasPrefix(line, " labels:"), and/or ensuring we’re not currently in inOnSteps / inOnPermissions).

			} else if strings.HasPrefix(trimmedLine, "labels:") {
				shouldComment = true
				commentReason = " # Label filtering applied via job conditions"
			} else if inLabelsArray && strings.HasPrefix(trimmedLine, "-") {
				// Comment out array items in labels
				shouldComment = true
				commentReason = " # Label filtering applied via job conditions"

• Files reviewed: 2/2 changed files
• Comments generated: 1

[pelikhan]

@copilots review all comments

[pelikhan]

@copilot review all
Comments

[github-actions]

Hey @Copilot 👋 — great work fixing the on.labels push-time parse failure! The change to commentOutProcessedFieldsInOnSection is clean and targeted, and it's good to see tests updated in label_names_test.go to cover the new commenting behavior.

One small thing before this is ready for maintainer review:

• Add a PR description — the body currently only contains an agent task checklist. A short prose summary (1–3 sentences) explaining what is being changed and why (i.e., that top-level on.labels causes GitHub's workflow parser to reject the compiled YAML at push time, and this fixes it by commenting those fields out) would help reviewers quickly understand the intent without digging into the diff.

If you'd like a hand, you can assign this prompt to your coding agent:

Update the PR body for PR #31411 in github/gh-aw to replace the agent task checklist with a concise prose description explaining:
1. What is changing: the workflow compiler's `commentOutProcessedFieldsInOnSection` function now comments out top-level `on.labels` (and its array items) in compiled `.lock.yml` files.
2. Why: GitHub's workflow parser rejects YAML with a top-level `on.labels` key at push time, causing failures; label filtering is already handled via job-level `if` conditions, so commenting out `labels:` in the compiled output is safe and correct.
Keep it to 3–5 sentences.

Generated by Contribution Check · ● 7.6M · ◷

[Copilot]

@copilots review all comments

Addressed. I fixed the review-thread issue by restricting on.labels handling to true top-level on fields and excluding on.steps/on.permissions contexts (commit 4f86a83). I also added a regression test for nested labels inside on.steps, then tightened test cleanup/message quality (commit 642b762).

@copilot review all
Comments

Done — all actionable review comments have been addressed in 4f86a83 and follow-up test refinements in 642b762.

[pelikhan]

@copilot add fuzz tests

[Copilot]

@copilot add fuzz tests

Added fuzz tests in pkg/workflow/frontmatter_extraction_yaml_fuzz_test.go and pushed updates in commits 11ed609, 85d80f2, and 1f3d599.

They cover top-level on.labels comment-out behavior and nested on.steps labels: handling to prevent false label-filter annotations.