test: Enhance Coverage + CI (#1055)

Reviewed-on: https://gitea.com/gitea/runner/pulls/1055
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: bircni <bircni@icloud.com>

internal/pkg/metrics/metrics_test.go

@@ -0,0 +1,95 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package metrics
+
+import (
+	"context"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	runnerv1 "gitea.dev/actions-proto-go/runner/v1"
+	"github.com/prometheus/client_golang/prometheus"
+	dto "github.com/prometheus/client_model/go"
+	"github.com/stretchr/testify/require"
+)
+
+func TestResultToStatusLabel(t *testing.T) {
+	tests := []struct {
+		name   string
+		result runnerv1.Result
+		want   string
+	}{
+		{"success", runnerv1.Result_RESULT_SUCCESS, LabelStatusSuccess},
+		{"failure", runnerv1.Result_RESULT_FAILURE, LabelStatusFailure},
+		{"cancelled", runnerv1.Result_RESULT_CANCELLED, LabelStatusCancelled},
+		{"skipped", runnerv1.Result_RESULT_SKIPPED, LabelStatusSkipped},
+		{"unspecified", runnerv1.Result_RESULT_UNSPECIFIED, LabelStatusUnknown},
+		{"out of range", runnerv1.Result(999), LabelStatusUnknown},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			require.Equal(t, tt.want, ResultToStatusLabel(tt.result))
+		})
+	}
+}
+
+func TestInitAndDynamicMetricRegistration(t *testing.T) {
+	oldRegistry := Registry
+	t.Cleanup(func() {
+		Registry = oldRegistry
+	})
+
+	Registry = prometheus.NewRegistry()
+	initOnce = sync.Once{}
+
+	Init()
+	Init()
+	RunnerInfo.WithLabelValues("test", "runner").Set(1)
+	RegisterUptimeFunc(time.Now().Add(-time.Second))
+	RegisterRunningJobsFunc(func() int64 { return 2 }, 4)
+
+	metrics, err := Registry.Gather()
+	require.NoError(t, err)
+
+	require.True(t, hasMetric(metrics, "gitea_runner_info"))
+	require.True(t, hasMetric(metrics, "gitea_runner_uptime_seconds"))
+	require.True(t, hasMetric(metrics, "gitea_runner_job_running"))
+	require.True(t, hasMetric(metrics, "gitea_runner_job_capacity_utilization_ratio"))
+}
+
+func TestRegisterRunningJobsFuncZeroCapacity(t *testing.T) {
+	oldRegistry := Registry
+	t.Cleanup(func() { Registry = oldRegistry })
+	Registry = prometheus.NewRegistry()
+
+	RegisterRunningJobsFunc(func() int64 { return 3 }, 0)
+
+	metrics, err := Registry.Gather()
+	require.NoError(t, err)
+	for _, mf := range metrics {
+		if mf.GetName() == "gitea_runner_job_capacity_utilization_ratio" {
+			require.Len(t, mf.GetMetric(), 1)
+			require.InDelta(t, 0, mf.GetMetric()[0].GetGauge().GetValue(), 0)
+			return
+		}
+	}
+	t.Fatal("capacity utilization metric not gathered")
+}
+
+func TestStartServerCanBeCancelled(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	StartServer(ctx, "127.0.0.1:0")
+	cancel()
+}
+
+func hasMetric(metrics []*dto.MetricFamily, name string) bool {
+	for _, mf := range metrics {
+		if strings.EqualFold(mf.GetName(), name) {
+			return true
+		}
+	}
+	return false
+}