feat: Add original response data changer

Author: igorjacauna

README.md

@@ -55,6 +55,17 @@ proxy.onGet('/path-to-request').changeRequest((requestConfig) => {
   return requestConfig;
 });
 
+// Can change original response data
+proxy.onGet('/').changeResponseData(originalData => ({
+  ...originalData,
+  override: 'another value',
+}));
+
+proxy.onGet('/').changeResponseDataOnce(originalData => ({
+  ...originalData,
+  override: 'another value once',
+}));
+
 // Or just want to see the response change the AxiosRequestConfig
 proxy.onGet('/path-to-request').printResponse();
 

src/runtime/handler.ts

@@ -1,5 +1,9 @@
 import type { AxiosResponse } from 'axios';
-import type { RequestConfigChanger, RouteConfig } from '../types';
+import type {
+  RequestConfigChanger,
+  ResponseChanger,
+  RouteConfig,
+} from '../types';
 import {
   ejectFromRequest,
   ejectFromResponse,
@@ -105,14 +109,34 @@ export default class Handler {
       response => {
         if (matchResponse(verbConfig, pathConfig, response, paramsConfig)) {
           if (once) ejectFromResponse(this.scope.axios, interceptorId);
+          // eslint-disable-next-line no-console
           console.log('Response from:', this.path);
+          // eslint-disable-next-line no-console
           console.log(JSON.stringify(response.data, null, 2));
         }
         return response;
       },
     );
   }
 
+  private setChangerResponseData(
+    responseChanger: ResponseChanger,
+    once = false,
+  ) {
+    const verbConfig = this.verb;
+    const pathConfig = this.path;
+    const paramsConfig = this.params;
+    const interceptorId = this.scope.axios.interceptors.response.use(
+      response => {
+        if (matchResponse(verbConfig, pathConfig, response, paramsConfig)) {
+          if (once) ejectFromResponse(this.scope.axios, interceptorId);
+          response.data = responseChanger(response.data);
+        }
+        return response;
+      },
+    );
+  }
+
   reply(statusCodeOrConfig: number | RouteConfig, mock?: unknown) {
     this.setProxy(statusCodeOrConfig, mock);
     return this.scope;
@@ -142,4 +166,14 @@ export default class Handler {
     this.setPrintableResponse(true);
     return this;
   }
+
+  changeResponseData(changer: ResponseChanger) {
+    this.setChangerResponseData(changer);
+    return this;
+  }
+
+  changeResponseDataOnce(changer: ResponseChanger) {
+    this.setChangerResponseData(changer, true);
+    return this;
+  }
 }

src/types.ts

@@ -1,4 +1,8 @@
-import type { AxiosRequestConfig, InternalAxiosRequestConfig } from 'axios';
+import type {
+  AxiosRequestConfig,
+  InternalAxiosRequestConfig,
+  AxiosResponse,
+} from 'axios';
 
 export type RouteConfig = (
   config?: AxiosRequestConfig,
@@ -7,3 +11,5 @@ export type RouteConfig = (
 export type RequestConfigChanger = (
   config: InternalAxiosRequestConfig,
 ) => InternalAxiosRequestConfig;
+
+export type ResponseChanger = (response: AxiosResponse) => AxiosResponse;

test/index.test.ts

@@ -227,6 +227,20 @@ describe('axios-dev-proxy tests', () => {
       expect(response.data).toEqual({ data: 2 });
       expect(response.status).toEqual(201);
     });
+
+    it('should change original response', async () => {
+      server.get('/').reply(200, { data: 1, xpto: 2 });
+
+      proxy.onGet('/').changeResponseDataOnce(data => ({
+        ...data,
+        data: 2,
+      }));
+
+      const response = await api.get('/');
+
+      expect(response.data).toEqual({ data: 2, xpto: 2 });
+      expect(response.status).toEqual(200);
+    });
   });
 
   describe('always GET configs', () => {