Method extractConcurrencySection

pkg/workflow/workflow_builder.go:513–547

extractConcurrencySection extracts the workflow-level concurrency YAML section, stripping the gh-aw-specific job-discriminator field so it does not appear in the compiled lock file (which must be valid GitHub Actions YAML).

(frontmatter map[string]any)

// stripping the gh-aw-specific job-discriminator field so it does not appear in
// the compiled lock file (which must be valid GitHub Actions YAML).
func (c *Compiler) extractConcurrencySection(frontmatter map[string]any) string {
	concurrencyRaw, ok := frontmatter["concurrency"]
	if !ok {
		return ""
	}
	concurrencyMap, ok := concurrencyRaw.(map[string]any)
	if !ok || len(concurrencyMap) == 0 {
		// String or empty format: serialize as-is (no job-discriminator possible)
		return c.extractTopLevelYAMLSection(frontmatter, "concurrency")
	}

	_, hasDiscriminator := concurrencyMap["job-discriminator"]
	if !hasDiscriminator {
		return c.extractTopLevelYAMLSection(frontmatter, "concurrency")
	}

	// Build a copy of the concurrency map without job-discriminator for serialization.
	// Use len(concurrencyMap) for capacity: at most one entry (job-discriminator) will be
	// omitted, so this is a slight over-allocation that avoids a subtle negative-capacity
	// edge case if job-discriminator were the only key.
	cleanMap := make(map[string]any, len(concurrencyMap))
	for k, v := range concurrencyMap {
		if k != "job-discriminator" {
			cleanMap[k] = v
		}
	}
	// When job-discriminator is the only field, there is no user-specified workflow-level
	// group to emit; return empty so the compiler can generate the default concurrency.
	if len(cleanMap) == 0 {
		return ""
	}
	// Use a minimal temporary frontmatter containing only the concurrency key to avoid
	// copying the entire (potentially large) frontmatter map.
	return c.extractTopLevelYAMLSection(map[string]any{"concurrency": cleanMap}, "concurrency")
}

// extractDispatchItemNumber reports whether the frontmatter's on.workflow_dispatch
// trigger exposes an item_number input. This is the signature produced by the label