Use @mswjs/interceptors for mocking - WIP

lib/create_response.js

@@ -0,0 +1,60 @@
+const { IncomingHttpHeaders, IncomingMessage } = require('http')
+
+/**
+ * Creates a Fetch API `Response` instance from the given
+ * `http.IncomingMessage` instance.
+ * copied from: https://github.com/mswjs/interceptors/blob/04152ed914f8041272b6e92ed374216b8177e1b2/src/interceptors/ClientRequest/utils/createResponse.ts#L8
+ */
+
+/**
+ * @param {IncomingMessage} message 
+ */
+function createResponse(message) {
+  const readable = new ReadableStream({
+    start(controller) {
+      message.on('data', (chunk) => controller.enqueue(chunk))
+      message.on('end', () => controller.close())
+
+      /**
+       * @todo Should also listen to the "error" on the message
+       * and forward it to the controller. Otherwise the stream
+       * will pend indefinitely.
+       */
+    },
+  })
+
+  return new Response(readable, {
+    status: message.statusCode,
+    statusText: message.statusMessage,
+    headers: createHeadersFromIncomingHttpHeaders(message.headers),
+  })
+}
+
+/**
+ * @param {IncomingHttpHeaders} httpHeaders 
+ */
+function createHeadersFromIncomingHttpHeaders(httpHeaders) {
+  const headers = new Headers()
+
+  for (const headerName in httpHeaders) {
+    const headerValues = httpHeaders[headerName]
+
+    if (typeof headerValues === 'undefined') {
+      continue
+    }
+
+    if (Array.isArray(headerValues)) {
+      headerValues.forEach((headerValue) => {
+        headers.append(headerName, headerValue)
+      })
+
+      continue
+    }
+
+    headers.set(headerName, headerValues)
+  }
+
+  return headers
+}
+
+module.exports = { createResponse }

lib/intercept.js

@@ -13,7 +13,8 @@
 const { BatchInterceptor } = require('@mswjs/interceptors')
 const { FetchInterceptor } = require('@mswjs/interceptors/fetch')
 const { default: nodeInterceptors } = require('@mswjs/interceptors/presets/node')
 const { once } = require('events')
+const { createResponse } = require('./create_response')
 
 /**
  * @name NetConnectNotAllowedError
@@ -380,10 +381,7 @@
     headers: Object.fromEntries(fetchRequest.headers.entries())
   };
 
-  const clientRequest = new http.ClientRequest(options);
-  // Note: You won't have access to the request body data from the Fetch Request
-
-  return clientRequest;
+  return new http.ClientRequest(options);
 }
 
 function activate() {
@@ -397,7 +395,8 @@
     interceptors: [...nodeInterceptors, new FetchInterceptor()],
   })
   interceptor.apply();
-  interceptor.on('request', async function ({ request, requestId }) {
+  interceptor.on('request', function ({ request, requestId }) {
+    return new Promise(resolve => {
       const { options, callback } = common.normalizeClientRequestArgs(request.url)
       options.proto = options.protocol.slice(0, -1)
       const interceptors = interceptorsFor(options)
@@ -425,24 +424,28 @@
           throw new Error('TODO')
         }
 
-        const req = convertFetchRequestToClientRequest(request);
-        req.on('response', response => {
-          request.respondWith(new Response('test', { status: 200 }))
+        const nockRequest = convertFetchRequestToClientRequest(request);
+        nockRequest.on('response', nockResponse => {
+          const response = createResponse(nockResponse)
+          nockResponse.on('end', () => {
+            request.respondWith(response)
+            resolve()
+          })
         })
 
-        req.end()
-        await once(req, 'response')
+        nockRequest.end()
       } else {
         globalEmitter.emit('no match', options)
         if (isOff() || isEnabledForNetConnect(options)) {
           // TODO: implement unmocked
           return overriddenRequest(options, callback)
         } else {
           const error = new NetConnectNotAllowedError(options.host, options.path)
           return new ErroringClientRequest(error)
         }
       }
     })
+  })
 }
 
 module.exports = {