add interceptor for http clients

Author: Ramanjs

integrations/khttp/require.ts

@@ -0,0 +1,175 @@
+/* eslint-disable @typescript-eslint/no-explicit-any */
+// @ts-ignore
+import { ResponseInit } from "node-fetch";
+import { getExecutionContext } from "../../src/context";
+import { Readable } from "stream";
+import { ProcessDep, stringToBinary } from "../../src/util";
+import { putMocks } from "../../mock/utils";
+import { HTTP, V1_BETA2 } from "../../src/keploy";
+import { getRequestHeader, getResponseHeader } from "../express/middleware";
+import { getReasonPhrase } from "http-status-codes";
+import { DataBytes } from "../../proto/services/DataBytes";
+import { MockIds } from "../../mock/mock";
+
+import { BatchInterceptor  } from '@mswjs/interceptors'
+import { ClientRequestInterceptor  } from '@mswjs/interceptors/ClientRequest'
+import { XMLHttpRequestInterceptor  } from '@mswjs/interceptors/XMLHttpRequest'
+
+function getHeadersInit(headers: { [k: string]: string[] }): {
+  [k: string]: string;
+} {
+  const result: { [key: string]: string } = {};
+  for (const key in headers) {
+    result[key] = headers[key].join(", ");
+  }
+  return result;
+}
+
+async function streamToString(stream: any) {
+   const chunks: Buffer[] = [];
+  
+   for await (const chunk of stream) {
+     chunks.push(Buffer.from(chunk));
+   }
+
+   return Buffer.concat(chunks).toString("utf-8");
+}
+
+async function streamToBuffer(stream: any) {
+   const chunks: Buffer[] = [];
+   for await (const chunk of stream) {
+     chunks.push(Buffer.from(chunk));
+   }
+   return chunks
+}
+
+const interceptor = new BatchInterceptor({
+  name: 'my-interceptor',
+  interceptors: [
+    new ClientRequestInterceptor(),
+    new XMLHttpRequestInterceptor(),
+  ],
+})
+
+interceptor.apply()
+
+interceptor.on('request', async (request, requestId) => {
+  if (
+    getExecutionContext() == undefined ||
+    getExecutionContext().context == undefined
+  ) {
+    console.error("keploy context is not present to mock dependencies");
+    return;
+  }
+  const ctx = getExecutionContext().context;
+  const meta = {
+    name: "khttp",
+    url: request.url,
+    type: "HTTP_CLIENT",
+  };
+  if (ctx.mode === 'test') {
+    const outputs = new Array(2);
+    if (
+      ctx.mocks != undefined &&
+      ctx.mocks.length > 0 &&
+      ctx.mocks[0].Kind == HTTP
+    ) {
+      const header: { [key: string]: string[] } = {};
+      for (const k in ctx.mocks[0].Spec?.Res?.Header) {
+        header[k] = ctx.mocks[0].Spec?.Res?.Header[k]?.Value;
+      }
+      outputs[1] = {
+        headers: getHeadersInit(header),
+        status: ctx.mocks[0].Spec.Res.StatusCode,
+        statusText: getReasonPhrase(ctx.mocks[0].Spec.Res.StatusCode),
+      };
+      outputs[0] = [ctx.mocks[0].Spec.Res.Body];
+      if (ctx?.fileExport) {
+        console.log(
+          "🤡 Returned the mocked outputs for Http dependency call with meta: ",
+          meta
+        );
+      }
+      ctx.mocks.shift();
+    } else {
+      ProcessDep({}, outputs);
+    }
+    //rinit.headers = new Headers(outputs[1].headers);
+    const buf: Buffer[] = [];
+    outputs[0].map((el: any) => {
+      buf.push(Buffer.from(el));
+    });
+    const bodyText = await streamToString(Readable.from(buf))
+    request.respondWith(
+      new Response(
+        bodyText,
+        {
+          status: outputs[1].status,
+          statusText: outputs[1].statusText,
+          headers: outputs[1].headers
+        }
+      )
+    )
+  }
+})
+
+interceptor.on('response', async (response, request) => {
+  if (
+    getExecutionContext() == undefined ||
+    getExecutionContext().context == undefined
+  ) {
+    console.error("keploy context is not present to mock dependencies");
+    return;
+  }
+  const ctx = getExecutionContext().context;
+  let rinit: ResponseInit = {};
+  const meta = {
+    name: "khttp",
+    url: request.url,
+    type: "HTTP_CLIENT",
+  };
+  if (ctx.mode === 'record') {
+    rinit = {
+      headers: Object.fromEntries(response.headers),
+      status: response.status,
+      statusText: response.statusText,
+    };
+    let respData: Buffer[] = [];
+    respData = await streamToBuffer(response.body)
+    let body = await streamToString(response.body)
+    const httpMock = {
+      Version: V1_BETA2,
+      Name: ctx.testId,
+      Kind: HTTP,
+      Spec: {
+        Metadata: meta,
+        Req: {
+          URL: request.url,
+          Body: JSON.stringify(request.body),
+          Header: getRequestHeader(Object.fromEntries(request.headers)),
+          Method: request.method,
+        },
+        Res: {
+          StatusCode: response.status,
+          Header: getResponseHeader(rinit.headers),
+          Body: body
+        },
+      },
+    };
+    // record mocks for unit-test-mock-library
+    if (ctx.fileExport === true) {
+      MockIds[ctx.testId] !== true ? putMocks(httpMock) : "";
+    } else {
+      ctx.mocks.push(httpMock);
+      const res: DataBytes[] = [];
+      res.push({ Bin: stringToBinary(JSON.stringify(respData)) });
+      res.push({ Bin: stringToBinary(JSON.stringify(rinit)) });
+      ctx.deps.push({
+        Name: meta.name,
+        Type: meta.type,
+        Meta: meta,
+        Data: res,
+      });
+    }
+  }
+})

package.json

@@ -42,6 +42,7 @@
   "dependencies": {
     "@grpc/grpc-js": "^1.7.1",
     "@grpc/proto-loader": "^0.7.3",
+    "@mswjs/interceptors": "^0.22.7",
     "cors": "^2.8.5",
     "express": "^4.17.3",
     "got": "^11.5.2",