Method fetchIndex

pkg/toolinstall/registry.go:270–293

fetchIndex fetches and parses the full registry index. The raw YAML is cached to disk; on fetch failure the cached copy is used. The YAML is re-parsed on every call — there is no in-memory cache.

(ctx context.Context)

// The raw YAML is cached to disk; on fetch failure the cached copy is used.
// The YAML is re-parsed on every call — there is no in-memory cache.
func (r *Registry) fetchIndex(ctx context.Context) (*registryIndex, error) {
	cachePath := filepath.Join(r.cacheDir, registryIndexFile)

	data, err := r.getBody(ctx, r.baseURL+"/"+registryIndexFile)
	if err != nil {
		// Fallback to stale disk cache.
		if cached, readErr := os.ReadFile(cachePath); readErr == nil {
			data = cached
		} else {
			return nil, err
		}
	} else {
		// Best-effort: persist to disk for future fallback.
		_ = os.MkdirAll(filepath.Dir(cachePath), 0o700)
		_ = atomicfile.Write(cachePath, bytes.NewReader(data), 0o600)
	}

	var index registryIndex
	if err := yaml.Unmarshal(data, &index); err != nil {
		return nil, fmt.Errorf("parsing registry index: %w", err)
	}

	return &index, nil
}

// githubRelease represents the relevant fields from the GitHub releases API.
type githubRelease struct {