Transport options (variant B)

test/ts/src/testRpcCombinations.ts

@@ -57,6 +57,10 @@ export function runWithSupportedTransports(cb: (transport: grpc.TransportConstru
     "defaultTransport": undefined
   };
 
+  if (typeof window !== "undefined") {
+    transports["fetchWithOptions"] = grpc.transports.fetchRequestWithOptions({})
+  }
+
   if (!process.env.DISABLE_WEBSOCKET_TESTS) {
     transports["websocketTransport"] = grpc.WebsocketTransportFactory
   }

ts/src/index.ts

@@ -7,6 +7,8 @@ import * as impClient from "./client";
 import * as impService from "./service";
 import * as impMessage from "./message";
 
+import * as impTransportFetch from "./transports/fetch";
+
 export namespace grpc {
   export interface ProtobufMessageClass<T extends ProtobufMessage> extends impMessage.ProtobufMessageClass<T> {}
   export interface ProtobufMessage extends impMessage.ProtobufMessage {}
@@ -37,4 +39,8 @@ export namespace grpc {
   export const unary = impUnary.unary;
   export interface UnaryOutput<TResponse extends ProtobufMessage> extends impUnary.UnaryOutput<TResponse> {}
   export interface UnaryRpcOptions<TRequest extends ProtobufMessage, TResponse extends ProtobufMessage> extends impUnary.UnaryRpcOptions<TRequest, TResponse> {}
+
+  export namespace transports {
+    export const fetchRequestWithOptions = impTransportFetch.fetchRequestWithOptions;
+  }
 }

ts/src/transports/fetch.ts

@@ -3,10 +3,21 @@ import {Transport, TransportOptions} from "./Transport";
 import {debug} from "../debug";
 import detach from "../detach";
 
+interface FetchOptions {
+  credentials?: RequestCredentials;
+}
+
+/* fetchRequestWithOptions provides a way to construct a Fetch transport with custom FetchOptions */
+export function fetchRequestWithOptions(fetchOptions: FetchOptions = {}): (options: TransportOptions) => Transport {
+  return function(options: TransportOptions) {
+    return fetchRequest(options, fetchOptions);
+  }
+}
+
 /* fetchRequest uses Fetch (with ReadableStream) to read response chunks without buffering the entire response. */
-export default function fetchRequest(options: TransportOptions): Transport {
-  options.debug && debug("fetchRequest", options);
-  return new Fetch(options);
+export default function fetchRequest(options: TransportOptions, fetchOptions: FetchOptions = {}): Transport {
+  options.debug && debug("fetchRequest", options, fetchOptions);
+  return new Fetch(options, fetchOptions);
 }
 
 declare const Response: any;
@@ -19,7 +30,7 @@ class Fetch implements Transport {
   metadata: Metadata;
   controller: AbortController | undefined = (window as any).AbortController && new AbortController();
 
-  constructor(transportOptions: TransportOptions) {
+  constructor(transportOptions: TransportOptions, private readonly fetchOptions: FetchOptions) {
     this.options = transportOptions;
   }
 
@@ -63,7 +74,7 @@ class Fetch implements Transport {
       headers: this.metadata.toHeaders(),
       method: "POST",
       body: msgBytes,
-      credentials: "same-origin",
+      credentials: this.fetchOptions.credentials || "same-origin",
       signal: this.controller && this.controller.signal
     }).then((res: Response) => {
       this.options.debug && debug("Fetch.response", res);