test(gcp): keep fixture pricing tests off ambient cloud credentials

providers/gcp/internal/billingguard/billingguard.go

@@ -0,0 +1,65 @@
+// Package billingguard keeps GCP service tests off the real Cloud Billing
+// Catalog. Production code logs and swallows a failed billing-service
+// construction, so a test that forgot to inject a fake would otherwise pass
+// silently on a CI runner and hit the network on a developer machine.
+package billingguard
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"path/filepath"
+	"sync"
+	"testing"
+)
+
+const marker = "failed to create billing service"
+
+type watcher struct {
+	next io.Writer
+	mu   sync.Mutex
+	hits []string
+}
+
+func (w *watcher) Write(p []byte) (int, error) {
+	if bytes.Contains(p, []byte(marker)) {
+		w.mu.Lock()
+		w.hits = append(w.hits, string(bytes.TrimSpace(p)))
+		w.mu.Unlock()
+	}
+	return w.next.Write(p)
+}
+
+// Run is for a package's TestMain. It points Application Default Credentials
+// at a missing file and the metadata server at a closed port, so the real
+// billing client cannot be built, then fails the package if any test tried.
+func Run(m *testing.M) int {
+	for k, v := range map[string]string{
+		"GOOGLE_APPLICATION_CREDENTIALS": "/nonexistent/billingguard-no-adc.json",
+		"GCE_METADATA_HOST":              "127.0.0.1:1",
+		"CLOUDSDK_CONFIG":                filepath.Join(os.TempDir(), "billingguard-no-gcloud"),
+	} {
+		if err := os.Setenv(k, v); err != nil {
+			fmt.Fprintf(os.Stderr, "billingguard: cannot isolate %s: %v\n", k, err)
+			return 1
+		}
+	}
+	if err := os.Unsetenv("GOOGLE_API_KEY"); err != nil {
+		fmt.Fprintf(os.Stderr, "billingguard: cannot unset GOOGLE_API_KEY: %v\n", err)
+		return 1
+	}
+
+	w := &watcher{next: os.Stderr}
+	log.SetOutput(w)
+	code := m.Run()
+	if code == 0 && len(w.hits) > 0 {
+		fmt.Fprintf(os.Stderr, "billingguard: %d test(s) reached the real billing service; inject a BillingService fake:\n", len(w.hits))
+		for _, h := range w.hits {
+			fmt.Fprintln(os.Stderr, "  "+h)
+		}
+		return 1
+	}
+	return code
+}

providers/gcp/services/cloudsql/client_test.go

@@ -600,6 +600,7 @@ func TestCloudSQLClient_GetOfferingDetails_APIError(t *testing.T) {
 func TestCloudSQLClient_GetRecommendations_WithMock(t *testing.T) {
 	ctx := context.Background()
 	client, _ := NewClient(ctx, "test-project", "us-central1")
+	client.SetBillingService(&MockBillingService{err: errors.New("catalog not under test")})
 
 	mockIterator := &MockRecommenderIterator{
 		recommendations: []*recommenderpb.Recommendation{
@@ -704,6 +705,7 @@ func TestCloudSQLClient_SetterMethods(t *testing.T) {
 func TestCloudSQLClient_ConvertGCPRecommendation(t *testing.T) {
 	ctx := context.Background()
 	client, _ := NewClient(ctx, "test-project", "us-central1")
+	client.SetBillingService(&MockBillingService{err: errors.New("catalog not under test")})
 
 	gcpRec := &recommenderpb.Recommendation{
 		Name: "test-rec",

providers/gcp/services/cloudsql/main_test.go

@@ -0,0 +1,10 @@
+package cloudsql
+
+import (
+	"os"
+	"testing"
+
+	"github.com/LeanerCloud/cloud-commitments-go/providers/gcp/internal/billingguard"
+)
+
+func TestMain(m *testing.M) { os.Exit(billingguard.Run(m)) }

providers/gcp/services/cloudstorage/main_test.go

@@ -0,0 +1,10 @@
+package cloudstorage
+
+import (
+	"os"
+	"testing"
+
+	"github.com/LeanerCloud/cloud-commitments-go/providers/gcp/internal/billingguard"
+)
+
+func TestMain(m *testing.M) { os.Exit(billingguard.Run(m)) }

providers/gcp/services/computeengine/client_test.go

@@ -2367,6 +2367,7 @@ func TestConvertGCPRecommendationVCPUOnlyKeepsNilDetails(t *testing.T) {
 func TestGetRecommendationsStringMemoryAmountEndToEnd(t *testing.T) {
 	ctx := context.Background()
 	client, _ := NewClient(ctx, "test-project", "us-central1")
+	client.SetBillingService(&MockBillingService{err: errors.New("catalog not under test")})
 	input := commitmentOnlyCUDRecommendation()
 	input.StateInfo = &recommenderpb.RecommendationStateInfo{State: recommenderpb.RecommendationStateInfo_ACTIVE}
 	memoryOpOf(input).PathValue = &recommenderpb.Operation_Value{Value: structpb.NewStringValue("6144")}

providers/gcp/services/computeengine/main_test.go

@@ -0,0 +1,10 @@
+package computeengine
+
+import (
+	"os"
+	"testing"
+
+	"github.com/LeanerCloud/cloud-commitments-go/providers/gcp/internal/billingguard"
+)
+
+func TestMain(m *testing.M) { os.Exit(billingguard.Run(m)) }

providers/gcp/services/memorystore/client_test.go

@@ -602,6 +602,7 @@ func TestMemorystoreClient_GetRecommendations_WithMockClient(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			ctx := context.Background()
 			client, _ := NewClient(ctx, "test-project", "us-central1")
+			client.SetBillingService(&MockBillingService{err: errors.New("catalog not under test")})
 
 			mockClient := &MockRecommenderClient{
 				recommendations: tt.recommendations,
@@ -633,6 +634,7 @@ func TestMemorystoreClient_GetRecommendations_WithMockClient(t *testing.T) {
 func TestMemorystoreClient_ConvertGCPRecommendation(t *testing.T) {
 	ctx := context.Background()
 	client, _ := NewClient(ctx, "test-project", "us-central1")
+	client.SetBillingService(&MockBillingService{err: errors.New("catalog not under test")})
 
 	tests := []struct {
 		name         string

providers/gcp/services/memorystore/main_test.go

@@ -0,0 +1,10 @@
+package memorystore
+
+import (
+	"os"
+	"testing"
+
+	"github.com/LeanerCloud/cloud-commitments-go/providers/gcp/internal/billingguard"
+)
+
+func TestMain(m *testing.M) { os.Exit(billingguard.Run(m)) }