fix(storage): preserve supplied endpoint's scheme

storage/storage.go

@@ -139,12 +139,15 @@ func NewClient(ctx context.Context, opts ...option.ClientOption) (*Client, error
 	if err != nil {
 		return nil, fmt.Errorf("storage client: %v", err)
 	}
-	// Update readHost with the chosen endpoint.
+	// Update readHost and scheme with the chosen endpoint.
 	u, err := url.Parse(ep)
 	if err != nil {
 		return nil, fmt.Errorf("supplied endpoint %q is not valid: %v", ep, err)
 	}
 	readHost = u.Host
+	if u.Scheme != "" {
+		scheme = u.Scheme
+	}
 
 	return &Client{
 		hc:       hc,

storage/storage_test.go

@@ -1252,38 +1252,59 @@ func TestAttrToFieldMapCoverage(t *testing.T) {
 func TestWithEndpoint(t *testing.T) {
 	originalStorageEmulatorHost := os.Getenv("STORAGE_EMULATOR_HOST")
 	testCases := []struct {
+		desc                string
 		CustomEndpoint      string
 		StorageEmulatorHost string
 		WantRawBasePath     string
 		WantReadHost        string
 		WantScheme          string
 	}{
 		{
+			desc:                "No endpoint or emulator host specified",
 			CustomEndpoint:      "",
 			StorageEmulatorHost: "",
 			WantRawBasePath:     "https://storage.googleapis.com/storage/v1/",
 			WantReadHost:        "storage.googleapis.com",
 			WantScheme:          "https",
 		},
 		{
+			desc:                "With specified https endpoint, no specified emulator host",
 			CustomEndpoint:      "https://fake.gcs.com:8080/storage/v1",
 			StorageEmulatorHost: "",
 			WantRawBasePath:     "https://fake.gcs.com:8080/storage/v1",
 			WantReadHost:        "fake.gcs.com:8080",
 			WantScheme:          "https",
 		},
 		{
+			desc:                "With specified http endpoint, no specified emulator host",
+			CustomEndpoint:      "http://fake.gcs.com:8080/storage/v1",
+			StorageEmulatorHost: "",
+			WantRawBasePath:     "http://fake.gcs.com:8080/storage/v1",
+			WantReadHost:        "fake.gcs.com:8080",
+			WantScheme:          "http",
+		},
+		{
+			desc:                "Emulator host specified, no specified endpoint",
 			CustomEndpoint:      "",
 			StorageEmulatorHost: "http://emu.com",
 			WantRawBasePath:     "http://emu.com",
 			WantReadHost:        "emu.com",
 			WantScheme:          "http",
 		},
 		{
+			desc:                "Endpoint overrides emulator host when both are specified - https",
 			CustomEndpoint:      "https://fake.gcs.com:8080/storage/v1",
 			StorageEmulatorHost: "http://emu.com",
 			WantRawBasePath:     "https://fake.gcs.com:8080/storage/v1",
 			WantReadHost:        "fake.gcs.com:8080",
+			WantScheme:          "https",
+		},
+		{
+			desc:                "Endpoint overrides emulator host when both are specified - http",
+			CustomEndpoint:      "http://fake.gcs.com:8080/storage/v1",
+			StorageEmulatorHost: "https://emu.com",
+			WantRawBasePath:     "http://fake.gcs.com:8080/storage/v1",
+			WantReadHost:        "fake.gcs.com:8080",
 			WantScheme:          "http",
 		},
 	}
@@ -1299,13 +1320,13 @@ func TestWithEndpoint(t *testing.T) {
 		}
 
 		if c.raw.BasePath != tc.WantRawBasePath {
-			t.Errorf("raw.BasePath not set correctly: got %v, want %v", c.raw.BasePath, tc.WantRawBasePath)
+			t.Errorf("%s: raw.BasePath not set correctly\n\tgot %v, want %v", tc.desc, c.raw.BasePath, tc.WantRawBasePath)
 		}
 		if c.readHost != tc.WantReadHost {
-			t.Errorf("readHost not set correctly: got %v, want %v", c.readHost, tc.WantReadHost)
+			t.Errorf("%s: readHost not set correctly\n\tgot %v, want %v", tc.desc, c.readHost, tc.WantReadHost)
 		}
 		if c.scheme != tc.WantScheme {
-			t.Errorf("scheme not set correctly: got %v, want %v", c.scheme, tc.WantScheme)
+			t.Errorf("%s: scheme not set correctly\n\tgot %v, want %v", tc.desc, c.scheme, tc.WantScheme)
 		}
 	}
 	os.Setenv("STORAGE_EMULATOR_HOST", originalStorageEmulatorHost)