Function extractPromautoMetric

scripts/metricsdocgen/scanner/scanner.go:627–675

extractPromautoMetric extracts a metric from promauto.With().New*() or factory.New*() calls. Supported patterns: - promauto.With(reg).NewCounterVec(prometheus.CounterOpts{...}, labels) - factory.NewGaugeVec(prometheus.GaugeOpts{...}, labels) where factory := promauto.With(reg)

(call *ast.CallExpr, decls declarations)

//   - promauto.With(reg).NewCounterVec(prometheus.CounterOpts{...}, labels)
//   - factory.NewGaugeVec(prometheus.GaugeOpts{...}, labels) where factory := promauto.With(reg)
func extractPromautoMetric(call *ast.CallExpr, decls declarations) (Metric, bool) {
	sel, ok := call.Fun.(*ast.SelectorExpr)
	if !ok {
		return Metric{}, false
	}

	funcName := sel.Sel.Name
	metricType, isVec := parseMetricFuncName(funcName)
	if metricType == "" {
		return Metric{}, false
	}

	// Check if this is a promauto call by examining the receiver.
	if !isPromautoCall(sel.X) {
		return Metric{}, false
	}

	// Need at least one argument (the Opts struct).
	if len(call.Args) < 1 {
		return Metric{}, false
	}

	// Extract metric info from the Opts struct.
	opts, ok := extractOpts(call.Args[0], decls)
	if !ok {
		warnf("extractPromautoMetric: skipping promauto.%s() call: could not extract opts", funcName)
		return Metric{}, false
	}

	// Extract labels for Vec types.
	var labels []string
	if isVec && len(call.Args) >= 2 {
		labels = extractLabels(call.Args[1], decls)
	}

	// Build the full metric name.
	name := buildMetricName(opts.Namespace, opts.Subsystem, opts.Name)
	if name == "" {
		warnf("extractPromautoMetric: skipping promauto.%s() call: could not build metric name", funcName)
		return Metric{}, false
	}

	return Metric{
		Name:   name,
		Type:   metricType,
		Help:   opts.Help,
		Labels: labels,
	}, true
}

// extractMetricFromCall attempts to extract a Metric from a function call expression.
// It returns the metric and true if successful, or an empty metric and false if