Fix mocking of gRPC-web and Connect GET requests

packages/connect-playwright-example/src/App.tsx

@@ -13,21 +13,51 @@
 // limitations under the License.
 
 import { useCallback, useState, FormEvent, FC } from "react";
-import { ConnectError, createPromiseClient } from "@connectrpc/connect";
-import { createConnectTransport } from "@connectrpc/connect-web";
+import {
+  ConnectError,
+  createPromiseClient,
+  PromiseClient,
+} from "@connectrpc/connect";
+import {
+  createGrpcWebTransport,
+  createConnectTransport,
+} from "@connectrpc/connect-web";
 import { ElizaService } from "./gen/connectrpc/eliza/v1/eliza_connect.js";
 
 interface ChatMessage {
   text: string;
   sender: "eliza" | "user";
 }
 
-const elizaClient = createPromiseClient(
-  ElizaService,
-  createConnectTransport({
-    baseUrl: "https://demo.connectrpc.com",
-  }),
-);
+const baseUrl = "https://demo.connectrpc.com";
+let elizaClient: PromiseClient<typeof ElizaService>;
+
+// Read the transport and format parameters from the URL
+// Note that users do not need to worry about this since this is just for
+// testing purposes so that we can easily verify various transports and
+// serialization formats.
+const params = new URLSearchParams(window.location.search);
+const transportParam = params.get("transport");
+const useBinaryFormat = params.get("format") === "binary";
+
+if (transportParam === "grpcweb") {
+  elizaClient = createPromiseClient(
+    ElizaService,
+    createGrpcWebTransport({
+      baseUrl,
+      useBinaryFormat,
+    }),
+  );
+} else {
+  elizaClient = createPromiseClient(
+    ElizaService,
+    createConnectTransport({
+      baseUrl,
+      useBinaryFormat,
+      useHttpGet: params.get("useHttpGet") === "true",
+    }),
+  );
+}
 
 const UnaryExample: FC = () => {
   const [inputValue, setInputValue] = useState<string>("");

packages/connect-playwright-example/tests/more.spec.ts

@@ -39,7 +39,7 @@ test.describe("more mocking", () => {
     await page.goto(project.use.baseURL ?? "");
 
     // Type some text and send
-    await statementInput.type("Hello");
+    await statementInput.fill("Hello");
     await sendButton.click();
 
     // This should NOT be the mocked response and instead should be passed through
@@ -54,7 +54,7 @@ test.describe("more mocking", () => {
       await page.goto(project.use.baseURL ?? "");
 
       // Type a name and send
-      await statementInput.type("Hello");
+      await statementInput.fill("Hello");
       await sendButton.click();
 
       // This should be empty text, because we configured the service with "mock" above,
@@ -84,7 +84,7 @@ test.describe("more mocking", () => {
       await page.goto(project.use.baseURL ?? "");
 
       // Type a name and send
-      await statementInput.type("Hello");
+      await statementInput.fill("Hello");
       await sendButton.click();
 
       // This should be the mocked response we set in our call to mock.rpc()
@@ -108,7 +108,7 @@ test.describe("more mocking", () => {
       await page.goto(project.use.baseURL ?? "");
 
       // Type a name and send
-      await statementInput.type("Hello");
+      await statementInput.fill("Hello");
       await sendButton.click();
 
       // This should be empty text, because we configured the service with "mock" above,
@@ -131,7 +131,7 @@ test.describe("more mocking", () => {
       await page.goto(project.use.baseURL ?? "");
 
       // Type a name and send
-      await statementInput.type("Hello");
+      await statementInput.fill("Hello");
       await sendButton.click();
 
       // This should be the mocked response we set in our call to mock.rpc()
@@ -151,7 +151,7 @@ test.describe("more mocking", () => {
       await page.goto(project.use.baseURL ?? "");
 
       // Type a name and send
-      await statementInput.type("Hello");
+      await statementInput.fill("Hello");
       await sendButton.click();
 
       // This should be empty text, because we configured the RPC with "mock" above,

packages/connect-playwright-example/tests/simple.spec.ts

@@ -47,7 +47,7 @@ test.describe("mocking Eliza", () => {
     await page.goto(project.use.baseURL ?? "");
 
     // Type a name and send
-    await statementInput.type("Hello");
+    await statementInput.fill("Hello");
     await sendButton.click();
 
     // This should be the mocked response we return from say() above
@@ -60,7 +60,7 @@ test.describe("mocking Eliza", () => {
     await page.goto(project.use.baseURL ?? "");
 
     // Type a name and send
-    await statementInput.type("Hello");
+    await statementInput.fill("Hello");
     await sendButton.click();
 
     // This should be empty text, because we configured the service with "mock" above,
@@ -81,7 +81,7 @@ test.describe("mocking Eliza", () => {
     await page.goto(project.use.baseURL ?? "");
 
     // Type a name and send
-    await statementInput.type("Hello");
+    await statementInput.fill("Hello");
     await sendButton.click();
 
     // In the app, calling say() rejected with a ConnectError.
@@ -100,7 +100,7 @@ test.describe("mocking Eliza", () => {
     await page.goto(project.use.baseURL ?? "");
 
     // Type a name and send
-    await statementInput.type("Hello");
+    await statementInput.fill("Hello");
     await sendButton.click();
 
     // This should NOT be the mocked response and instead should be passed through

packages/connect-playwright-example/tests/transport.spec.ts

@@ -0,0 +1,67 @@
+// Copyright 2023-2024 The Connect Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { expect, Locator, test } from "@playwright/test";
+
+import { ElizaService } from "../src/gen/connectrpc/eliza/v1/eliza_connect.js";
+import { createMockRouter, MockRouter } from "@connectrpc/connect-playwright";
+
+test.describe("transports", () => {
+  let respText: Locator;
+  let statementInput: Locator;
+  let sendButton: Locator;
+  let mock: MockRouter;
+  let baseURL = "";
+
+  test.beforeEach(async ({ page, context }, { project }) => {
+    respText = page.locator(".eliza-resp-container p");
+    statementInput = page.locator("#statement-input");
+    sendButton = page.locator("#send");
+
+    baseURL = project.use.baseURL ?? "";
+
+    mock = createMockRouter(context, {
+      baseUrl: "https://demo.connectrpc.com",
+    });
+
+    await mock.service(ElizaService, {
+      say() {
+        return {
+          sentence: "Mock response",
+        };
+      },
+    });
+  });
+
+  [
+    baseURL,
+    baseURL + "?transport=connect",
+    baseURL + "?transport=connect&useHttpGet=true",
+    baseURL + "?transport=connect&format=binary",
+    baseURL + "?transport=connect&format=binary&useHttpGet=true",
+    baseURL + "?transport=grpcweb",
+    baseURL + "?transport=grpcweb&format=json",
+  ].forEach((url) => {
+    test(`correctly mocks with params ${url}`, async ({ page }) => {
+      await page.goto(url);
+
+      // Type a name and send
+      await statementInput.fill("Hello");
+      await sendButton.click();
+
+      // This should be the mocked response we return from say() above
+      await expect(respText).toHaveText("Mock response");
+    });
+  });
+});

packages/connect-playwright/src/create-mock-router.ts

@@ -21,11 +21,18 @@ import type {
   BinaryReadOptions,
   BinaryWriteOptions,
   JsonReadOptions,
+  JsonValue,
   JsonWriteOptions,
 } from "@bufbuild/protobuf";
 import { MethodKind } from "@bufbuild/protobuf";
-import type { UniversalHandler } from "@connectrpc/connect/protocol";
-import { readAllBytes } from "@connectrpc/connect/protocol";
+import type {
+  UniversalHandler,
+  UniversalServerRequest,
+} from "@connectrpc/connect/protocol";
+import {
+  readAllBytes,
+  createAsyncIterable,
+} from "@connectrpc/connect/protocol";
 
 export interface MockRouter {
   service: <S extends ServiceType>(
@@ -55,6 +62,17 @@ interface Options {
   binaryOptions?: Partial<BinaryReadOptions & BinaryWriteOptions>;
 }
 
+// Builds a regular expression for matching paths by appending the suffix onto
+// base and escaping forward slashes and periods
+function buildPathRegex(base: string, suffix: string) {
+  const sanitized = base
+    .replace(/\/?$/, suffix)
+    .replace(/\./g, "\\.")
+    .replace(/\//g, "\\/");
+
+  return new RegExp(sanitized);
+}
+
 export function createMockRouter(
   context: BrowserContext,
   options: Options,
@@ -74,11 +92,13 @@ export function createMockRouter(
     if (method.kind !== MethodKind.Unary) {
       throw new Error("Cannot add non-unary method.");
     }
-    const requestPath = baseUrl
-      .toString()
-      .replace(/\/?$/, `/${service.typeName}/${method.name}`);
 
-    return context.route(requestPath, async (route, request) => {
+    const pathRegex = buildPathRegex(
+      baseUrl,
+      `/${service.typeName}/${method.name}`,
+    );
+
+    return context.route(pathRegex, async (route, request) => {
       if (handler !== "mock") {
         const router = createConnectRouter(routerOptions).rpc(
           service,
@@ -122,11 +142,9 @@ export function createMockRouter(
             }),
           );
         }
-        const requestPath = baseUrl
-          .toString()
-          .replace(/\/?$/, `/${service.typeName}/**`);
+        const pathRegex = buildPathRegex(baseUrl, `/${service.typeName}/*`);
 
-        return context.route(requestPath, async (route, request) => {
+        return context.route(pathRegex, async (route, request) => {
           const remainingPath = new URL(request.url()).pathname.replace(
             new RegExp(`^/${service.typeName}/`),
             "",
@@ -184,18 +202,26 @@ async function universalHandlerToRouteResponse({
 }) {
   const headers = await request.allHeaders();
   const abortSignal = new AbortController().signal;
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any -- The Serializable type isn't exposed by Playwright
-  let body: any;
+
+  // Default body to an empty byte stream
+  let body: UniversalServerRequest["body"] = createAsyncIterable<Uint8Array>(
+    [],
+  );
+
   if (headers["content-type"] === "application/json") {
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
-    body = request.postDataJSON();
+    // If content type headers are present and set to JSON, this is a POST
+    // request with a JSON body
+    body = request.postDataJSON() as JsonValue;
   } else {
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
-    body = request.postDataBuffer();
+    const buffer = request.postDataBuffer();
+    if (buffer !== null) {
+      // If postDataBuffer returns a non-null body, this is a POST
+      // request with a binary body
+      body = createAsyncIterable<Uint8Array>([buffer]);
+    }
   }
 
   const response = await routeHandler({
-    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment -- No current way around this, we just have no idea what this returns
     body,
     url: request.url(),
     header: new Headers(headers),