Add support for Azure Function v4

Author: charlesgardyn

README.md

@@ -23,10 +23,12 @@ npm install @as-integrations/azure-functions @apollo/server graphql @azure/funct
 
 ## **Usage**
 
+
 1. Setup an [Azure Function with TypeScript](https://learn.microsoft.com/azure/azure-functions/create-first-function-vs-code-typescript) (or [JavaScript](https://learn.microsoft.com/azure/azure-functions/create-first-function-vs-code-node)) as per normal.
 2. Create a new [HTTP Trigger](https://learn.microsoft.com/azure/azure-functions/functions-bindings-http-webhook-trigger?tabs=in-process%2Cfunctionsv2&pivots=programming-language-javascript)
 3. Update the `index.ts` to use the Apollo integration:
 
+**v3**
 ```ts
 import { ApolloServer } from '@apollo/server';
 import { startServerAndCreateHandler } from '@as-integrations/azure-functions';
@@ -54,7 +56,37 @@ const server = new ApolloServer({
 export default startServerAndCreateHandler(server);
 ```
 
-4. Update the `function.json` HTTP output binding to use `$return` as the name, as the integration returns from the Function Handler:
+**v4**
+```ts
+import { ApolloServer } from '@apollo/server';
+import { v4 } from '@as-integrations/azure-functions';
+
+// The GraphQL schema
+const typeDefs = `#graphql
+  type Query {
+    hello: String
+  }
+`;
+
+// A map of functions which return data for the schema.
+const resolvers = {
+  Query: {
+    hello: () => 'world',
+  },
+};
+
+// Set up Apollo Server
+const server = new ApolloServer({
+  typeDefs,
+  resolvers,
+});
+
+app.http('graphql', {
+  handler: v4.startServerAndCreateHandler(server),
+});
+```
+
+4. Update the `function.json` HTTP output binding to use `$return` as the name, as the integration returns from the Function Handler **(v3 only)**:
 
 ```json
 {

package-lock.json

@@ -55,7 +55,9 @@
   "dependencies": {
     "@apollo/server": "^4.1.1",
     "@azure/functions": "^3.2.0",
+    "@azure/functions-v4": "npm:@azure/functions@^4.1.0",
     "graphql": "^16.6.0",
-    "graphql-tag": "^2.12.6"
+    "graphql-tag": "^2.12.6",
+    "undici": "^5.27.2"
   }
 }

package.json

@@ -0,0 +1,46 @@
+import { ApolloServer, ApolloServerOptions, BaseContext } from '@apollo/server';
+import {
+  CreateServerForIntegrationTestsOptions,
+  defineIntegrationTestSuite,
+} from '@apollo/server-integration-testsuite';
+import { createServer } from 'http';
+import { v4 } from '..';
+import { createMockServer, urlForHttpServer } from './mockServer-v4';
+
+describe('Azure Functions v4', () => {
+  defineIntegrationTestSuite(
+    async function (
+      serverOptions: ApolloServerOptions<BaseContext>,
+      testOptions?: CreateServerForIntegrationTestsOptions,
+    ) {
+      const httpServer = createServer();
+      const server = new ApolloServer({
+        ...serverOptions,
+      });
+
+      const handler = testOptions
+        ? v4.startServerAndCreateHandler(server, testOptions)
+        : v4.startServerAndCreateHandler(server);
+
+      await new Promise<void>((resolve) => {
+        httpServer.listen({ port: 0 }, resolve);
+      });
+
+      httpServer.addListener('request', createMockServer(handler));
+
+      return {
+        server,
+        url: urlForHttpServer(httpServer),
+        async extraCleanup() {
+          await new Promise<void>((resolve) => {
+            httpServer.close(() => resolve());
+          });
+        },
+      };
+    },
+    {
+      serverIsStartedInBackground: true,
+      noIncrementalDelivery: true,
+    },
+  );
+});

src/__tests__/func-v4.test.ts

@@ -0,0 +1,72 @@
+import {
+  HttpHandler,
+  InvocationContext,
+  type HttpMethod,
+  type HttpRequest,
+} from '@azure/functions-v4';
+import type { IncomingMessage, Server, ServerResponse } from 'http';
+import type { AddressInfo } from 'net';
+import { Headers, HeadersInit } from 'undici';
+
+export function urlForHttpServer(httpServer: Server): string {
+  const { address, port } = httpServer.address() as AddressInfo;
+
+  // Convert IPs which mean "any address" (IPv4 or IPv6) into localhost
+  // corresponding loopback ip. Note that the url field we're setting is
+  // primarily for consumption by our test suite. If this heuristic is wrong for
+  // your use case, explicitly specify a frontend host (in the `host` option
+  // when listening).
+  const hostname = address === '' || address === '::' ? 'localhost' : address;
+
+  return `http://${hostname}:${port}`;
+}
+
+export const createMockServer = (handler: HttpHandler) => {
+  return (req: IncomingMessage, res: ServerResponse) => {
+    let body = '';
+    req.on('data', (chunk) => (body += chunk));
+
+    req.on('end', async () => {
+      const azReq: HttpRequest = {
+        method: (req.method as HttpMethod) || null,
+        url: new URL(req.url || '', 'http://localhost').toString(),
+        headers: new Headers(req.headers as HeadersInit),
+        body,
+        query: new URLSearchParams(req.url),
+        params: {},
+        user: null,
+        arrayBuffer: async () => {
+          return Buffer.from(body).buffer;
+        },
+        text: async () => {
+          return body;
+        },
+        json: async () => {
+          return JSON.parse(body);
+        },
+        blob: async () => {
+          throw new Error('Not implemented');
+        },
+        bodyUsed: false,
+        formData: async () => {
+          throw new Error('Not implemented');
+        },
+      };
+
+      const context = new InvocationContext({
+        invocationId: 'mock',
+        functionName: 'mock',
+        logHandler: console.log,
+      });
+
+      const azRes = await handler(azReq, context);
+
+      res.statusCode = azRes.status || 200;
+      Object.entries(azRes.headers ?? {}).forEach(([key, value]) => {
+        res.setHeader(key, value!.toString());
+      });
+      res.write(azRes.body);
+      res.end();
+    });
+  };
+};