Enable user headers in the reflect call in client.connect

js/modules/k6/grpc/client.go

@@ -260,6 +260,13 @@ func (c *Client) Connect(addr string, params map[string]interface{}) (bool, erro
 	if !p.UseReflectionProtocol {
 		return true, nil
 	}
+
+	md := metadata.New(nil)
+	for param, strval := range p.ReflectMetadata {
+		md.Append(param, strval)
+	}
+	ctx = metadata.NewOutgoingContext(ctx, md)
+
 	fdset, err := c.conn.Reflect(ctx)
 	if err != nil {
 		return false, err
@@ -490,6 +497,7 @@ type connectParams struct {
 	MaxReceiveSize        int64
 	MaxSendSize           int64
 	TLS                   map[string]interface{}
+	ReflectMetadata       map[string]string
 }
 
 func (c *Client) parseConnectParams(raw map[string]interface{}) (connectParams, error) {
@@ -538,6 +546,20 @@ func (c *Client) parseConnectParams(raw map[string]interface{}) (connectParams,
 			if params.MaxSendSize < 0 {
 				return params, fmt.Errorf("invalid maxSendSize value: '%#v, it needs to be a positive integer", v)
 			}
+		case "reflectMetadata":
+			params.ReflectMetadata = make(map[string]string)
+			rawHeaders, ok := v.(map[string]interface{})
+			if !ok {
+				return params, errors.New("metadata must be an object with key-value pairs")
+			}
+			// Same way metadata is handled in invoke parameter parsing
+			for hk, kv := range rawHeaders {
+				strval, ok := kv.(string)
+				if !ok {
+					return params, fmt.Errorf("metadata %q value must be a string", hk)
+				}
+				params.ReflectMetadata[hk] = strval
+			}
 		case "tls":
 			var ok bool
 			params.TLS, ok = v.(map[string]interface{})

js/modules/k6/grpc/client_test.go

@@ -654,6 +654,20 @@ func TestClient(t *testing.T) {
 				err:  `invalid reflect value`,
 			},
 		},
+		{
+			name: "ReflectMetadata",
+			setup: func(tb *httpmultibin.HTTPMultiBin) {
+				reflection.Register(tb.ServerGRPC)
+			},
+			initString: codeBlock{
+				code: `var client = new grpc.Client();`,
+			},
+			vuString: codeBlock{
+				code: `
+					client.connect("GRPCBIN_ADDR", {reflect: true, reflectMetadata: { "X-Load-Tester": "k6" } })
+				`,
+			},
+		},
 		{
 			name: "ReflectInvokeNoExist",
 			setup: func(tb *httpmultibin.HTTPMultiBin) {