Minimize replaced code in grpc tests

exporter/chronicleexporter/grpc_exporter.go

@@ -26,6 +26,7 @@ import (
 	"go.opentelemetry.io/collector/consumer/consumererror"
 	"go.opentelemetry.io/collector/exporter"
 	"go.opentelemetry.io/collector/pdata/plog"
+	"golang.org/x/oauth2"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials"
@@ -69,7 +70,12 @@ func (exp *grpcExporter) Capabilities() consumer.Capabilities {
 }
 
 func (exp *grpcExporter) Start(ctx context.Context, _ component.Host) error {
-	conn, err := getGRPCClient(ctx, exp.cfg)
+	ts, err := tokenSource(ctx, exp.cfg)
+	if err != nil {
+		return fmt.Errorf("load Google credentials: %w", err)
+	}
+	endpoint, dialOpts := grpcClientParams(exp.cfg.Endpoint, ts)
+	conn, err := grpc.NewClient(endpoint, dialOpts...)
 	if err != nil {
 		return fmt.Errorf("dial: %w", err)
 	}
@@ -145,15 +151,10 @@ func (exp *grpcExporter) buildOptions() []grpc.CallOption {
 	return opts
 }
 
-var getGRPCClient func(context.Context, *Config) (*grpc.ClientConn, error) = buildGRPCClient
-
-func buildGRPCClient(ctx context.Context, cfg *Config) (*grpc.ClientConn, error) {
-	creds, err := googleCredentials(ctx, cfg)
-	if err != nil {
-		return nil, fmt.Errorf("load Google credentials: %w", err)
-	}
-	return grpc.NewClient(cfg.Endpoint+":443",
-		grpc.WithPerRPCCredentials(oauth.TokenSource{TokenSource: creds.TokenSource}),
+// Override for testing
+var grpcClientParams = func(cfgEndpoint string, ts oauth2.TokenSource) (string, []grpc.DialOption) {
+	return cfgEndpoint + ":443", []grpc.DialOption{
+		grpc.WithPerRPCCredentials(oauth.TokenSource{TokenSource: ts}),
 		grpc.WithTransportCredentials(credentials.NewClientTLSFromCert(nil, "")),
-	)
+	}
 }

exporter/chronicleexporter/grpc_exporter_test.go

@@ -25,6 +25,7 @@ import (
 	"go.opentelemetry.io/collector/consumer/consumererror"
 	"go.opentelemetry.io/collector/exporter/exportertest"
 	"go.opentelemetry.io/collector/pdata/plog"
+	"golang.org/x/oauth2"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/credentials/insecure"
@@ -66,6 +67,15 @@ func (s *mockGRPCServer) BatchCreateLogs(_ context.Context, req *api.BatchCreate
 }
 
 func TestGRPCExporter(t *testing.T) {
+	// Override the token source so that we don't have to provide real credentials
+	secureTokenSource := tokenSource
+	defer func() {
+		tokenSource = secureTokenSource
+	}()
+	tokenSource = func(context.Context, *Config) (oauth2.TokenSource, error) {
+		return &emptyTokenSource{}, nil
+	}
+
 	// By default, tests will apply the following changes to NewFactory.CreateDefaultConfig()
 	defaultCfgMod := func(cfg *Config) {
 		cfg.Protocol = protocolGRPC
@@ -145,13 +155,14 @@ func TestGRPCExporter(t *testing.T) {
 			mockServer, endpoint := newMockGRPCServer(t, tc.handler)
 			defer mockServer.srv.GracefulStop()
 
-			// Override the client builder so we can use the mock server
-			getGRPCClient = func(_ context.Context, _ *Config) (*grpc.ClientConn, error) {
-				return grpc.NewClient(endpoint, grpc.WithTransportCredentials(insecure.NewCredentials()))
-			}
+			// Override the client params for testing to we can connect to the mock server
+			secureGPPCClientParams := grpcClientParams
 			defer func() {
-				getGRPCClient = buildGRPCClient
+				grpcClientParams = secureGPPCClientParams
 			}()
+			grpcClientParams = func(string, oauth2.TokenSource) (string, []grpc.DialOption) {
+				return endpoint, []grpc.DialOption{grpc.WithTransportCredentials(insecure.NewCredentials())}
+			}
 
 			f := NewFactory()
 			cfg := f.CreateDefaultConfig().(*Config)

exporter/chronicleexporter/http_exporter.go

@@ -66,7 +66,7 @@ func (exp *httpExporter) Capabilities() consumer.Capabilities {
 }
 
 func (exp *httpExporter) Start(ctx context.Context, _ component.Host) error {
-	ts, err := getTokenSource(ctx, exp.cfg)
+	ts, err := tokenSource(ctx, exp.cfg)
 	if err != nil {
 		return fmt.Errorf("load Google credentials: %w", err)
 	}
@@ -119,7 +119,7 @@ func (exp *httpExporter) uploadToChronicleHTTP(ctx context.Context, logs *api.Im
 		body = bytes.NewBuffer(data)
 	}
 
-	request, err := http.NewRequestWithContext(ctx, "POST", getHTTPEndpoint(exp.cfg, logType), body)
+	request, err := http.NewRequestWithContext(ctx, "POST", httpEndpoint(exp.cfg, logType), body)
 	if err != nil {
 		return fmt.Errorf("create request: %w", err)
 	}
@@ -157,22 +157,10 @@ func (exp *httpExporter) uploadToChronicleHTTP(ctx context.Context, logs *api.Im
 	}
 }
 
-// Override for testing
-var getHTTPEndpoint = buildHTTPEndpoint
-
 // This uses the DataPlane URL for the request
 // URL for the request: https://{region}-chronicle.googleapis.com/{version}/projects/{project}/location/{region}/instances/{customerID}
-func buildHTTPEndpoint(cfg *Config, logType string) string {
+// Override for testing
+var httpEndpoint = func(cfg *Config, logType string) string {
 	formatString := "https://%s-%s/v1alpha/projects/%s/locations/%s/instances/%s/logTypes/%s/logs:import"
 	return fmt.Sprintf(formatString, cfg.Location, cfg.Endpoint, cfg.Project, cfg.Location, cfg.CustomerID, logType)
 }
-
-var getTokenSource func(context.Context, *Config) (oauth2.TokenSource, error) = googleTokenSource
-
-func googleTokenSource(ctx context.Context, cfg *Config) (oauth2.TokenSource, error) {
-	creds, err := googleCredentials(ctx, cfg)
-	if err != nil {
-		return nil, err
-	}
-	return creds.TokenSource, nil
-}

exporter/chronicleexporter/http_exporter_test.go

@@ -26,6 +26,7 @@ import (
 	"go.opentelemetry.io/collector/consumer/consumererror"
 	"go.opentelemetry.io/collector/exporter/exportertest"
 	"go.opentelemetry.io/collector/pdata/plog"
+	"golang.org/x/oauth2"
 )
 
 type mockHTTPServer struct {
@@ -47,12 +48,21 @@ func newMockHTTPServer(logTypeHandlers map[string]http.HandlerFunc) *mockHTTPSer
 	return &mockServer
 }
 
+type emptyTokenSource struct{}
+
+func (t *emptyTokenSource) Token() (*oauth2.Token, error) {
+	return &oauth2.Token{}, nil
+}
+
 func TestHTTPExporter(t *testing.T) {
 	// Override the token source so that we don't have to provide real credentials
-	getTokenSource = testTokenSource
+	secureTokenSource := tokenSource
 	defer func() {
-		getTokenSource = googleTokenSource
+		tokenSource = secureTokenSource
 	}()
+	tokenSource = func(context.Context, *Config) (oauth2.TokenSource, error) {
+		return &emptyTokenSource{}, nil
+	}
 
 	// By default, tests will apply the following changes to NewFactory.CreateDefaultConfig()
 	defaultCfgMod := func(cfg *Config) {
@@ -150,12 +160,13 @@ func TestHTTPExporter(t *testing.T) {
 			defer mockServer.srv.Close()
 
 			// Override the endpoint builder so that we can point to the mock server
-			getHTTPEndpoint = func(_ *Config, logType string) string {
-				return fmt.Sprintf("%s/logTypes/%s/logs:import", mockServer.srv.URL, logType)
-			}
+			secureHTTPEndpoint := httpEndpoint
 			defer func() {
-				getHTTPEndpoint = buildHTTPEndpoint
+				httpEndpoint = secureHTTPEndpoint
 			}()
+			httpEndpoint = func(_ *Config, logType string) string {
+				return fmt.Sprintf("%s/logTypes/%s/logs:import", mockServer.srv.URL, logType)
+			}
 
 			f := NewFactory()
 			cfg := f.CreateDefaultConfig().(*Config)

exporter/chronicleexporter/util.go

@@ -20,9 +20,19 @@ import (
 	"fmt"
 	"os"
 
+	"golang.org/x/oauth2"
 	"golang.org/x/oauth2/google"
 )
 
+// Override for testing
+var tokenSource = func(ctx context.Context, cfg *Config) (oauth2.TokenSource, error) {
+	creds, err := googleCredentials(ctx, cfg)
+	if err != nil {
+		return nil, err
+	}
+	return creds.TokenSource, nil
+}
+
 func googleCredentials(ctx context.Context, cfg *Config) (*google.Credentials, error) {
 	scope := grpcScope
 	if cfg.Protocol == protocolHTTPS {