From ad3fac577cca737976ed82cd9d55027eb8af654c Mon Sep 17 00:00:00 2001
From: Aras Abbasi <aras.abbasi@googlemail.com>
Date: Sun, 7 Apr 2024 14:08:01 +0200
Subject: [PATCH] mock: improve mock interceptor (#3062)

---
 lib/mock/mock-interceptor.js | 35 ++++++++++++++++++-----------------
 test/mock-interceptor.js     | 20 +++++++++++++++++---
 2 files changed, 35 insertions(+), 20 deletions(-)

diff --git a/lib/mock/mock-interceptor.js b/lib/mock/mock-interceptor.js
index d071a90db06..c6b16b35f9c 100644
--- a/lib/mock/mock-interceptor.js
+++ b/lib/mock/mock-interceptor.js
@@ -90,7 +90,7 @@ class MockInterceptor {
     this[kContentLength] = false
   }
 
-  createMockScopeDispatchData (statusCode, data, responseOptions = {}) {
+  createMockScopeDispatchData ({ statusCode, data, responseOptions }) {
     const responseData = getResponseData(data)
     const contentLength = this[kContentLength] ? { 'content-length': responseData.length } : {}
     const headers = { ...this[kDefaultHeaders], ...contentLength, ...responseOptions.headers }
@@ -99,14 +99,11 @@ class MockInterceptor {
     return { statusCode, data, headers, trailers }
   }
 
-  validateReplyParameters (statusCode, data, responseOptions) {
-    if (typeof statusCode === 'undefined') {
+  validateReplyParameters (replyParameters) {
+    if (typeof replyParameters.statusCode === 'undefined') {
       throw new InvalidArgumentError('statusCode must be defined')
     }
-    if (typeof data === 'undefined') {
-      throw new InvalidArgumentError('data must be defined')
-    }
-    if (typeof responseOptions !== 'object' || responseOptions === null) {
+    if (typeof replyParameters.responseOptions !== 'object' || replyParameters.responseOptions === null) {
       throw new InvalidArgumentError('responseOptions must be an object')
     }
   }
@@ -114,28 +111,28 @@ class MockInterceptor {
   /**
    * Mock an undici request with a defined reply.
    */
-  reply (replyData) {
+  reply (replyOptionsCallbackOrStatusCode) {
     // Values of reply aren't available right now as they
     // can only be available when the reply callback is invoked.
-    if (typeof replyData === 'function') {
+    if (typeof replyOptionsCallbackOrStatusCode === 'function') {
       // We'll first wrap the provided callback in another function,
       // this function will properly resolve the data from the callback
       // when invoked.
       const wrappedDefaultsCallback = (opts) => {
         // Our reply options callback contains the parameter for statusCode, data and options.
-        const resolvedData = replyData(opts)
+        const resolvedData = replyOptionsCallbackOrStatusCode(opts)
 
         // Check if it is in the right format
-        if (typeof resolvedData !== 'object') {
+        if (typeof resolvedData !== 'object' || resolvedData === null) {
           throw new InvalidArgumentError('reply options callback must return an object')
         }
 
-        const { statusCode, data = '', responseOptions = {} } = resolvedData
-        this.validateReplyParameters(statusCode, data, responseOptions)
+        const replyParameters = { data: '', responseOptions: {}, ...resolvedData }
+        this.validateReplyParameters(replyParameters)
         // Since the values can be obtained immediately we return them
         // from this higher order function that will be resolved later.
         return {
-          ...this.createMockScopeDispatchData(statusCode, data, responseOptions)
+          ...this.createMockScopeDispatchData(replyParameters)
         }
       }
 
@@ -148,11 +145,15 @@ class MockInterceptor {
     // we should have 1-3 parameters. So we spread the arguments of
     // this function to obtain the parameters, since replyData will always
     // just be the statusCode.
-    const [statusCode, data = '', responseOptions = {}] = [...arguments]
-    this.validateReplyParameters(statusCode, data, responseOptions)
+    const replyParameters = {
+      statusCode: replyOptionsCallbackOrStatusCode,
+      data: arguments[1] === undefined ? '' : arguments[1],
+      responseOptions: arguments[2] === undefined ? {} : arguments[2]
+    }
+    this.validateReplyParameters(replyParameters)
 
     // Send in-already provided data like usual
-    const dispatchData = this.createMockScopeDispatchData(statusCode, data, responseOptions)
+    const dispatchData = this.createMockScopeDispatchData(replyParameters)
     const newMockDispatch = addMockDispatch(this[kDispatches], this[kDispatchKey], dispatchData)
     return new MockScope(newMockDispatch)
   }
diff --git a/test/mock-interceptor.js b/test/mock-interceptor.js
index 961a7576dc1..0d16290f579 100644
--- a/test/mock-interceptor.js
+++ b/test/mock-interceptor.js
@@ -107,7 +107,7 @@ describe('MockInterceptor - reply options callback', () => {
   })
 
   test('should error if passed options invalid', async (t) => {
-    t = tspl(t, { plan: 3 })
+    t = tspl(t, { plan: 4 })
 
     const baseUrl = 'http://localhost:9999'
     const mockAgent = new MockAgent()
@@ -116,10 +116,15 @@ describe('MockInterceptor - reply options callback', () => {
     const mockPool = mockAgent.get(baseUrl)
 
     mockPool.intercept({
-      path: '/test',
+      path: '/test-return-undefined',
       method: 'GET'
     }).reply(() => { })
 
+    mockPool.intercept({
+      path: '/test-return-null',
+      method: 'GET'
+    }).reply(() => { return null })
+
     mockPool.intercept({
       path: '/test3',
       method: 'GET'
@@ -138,7 +143,16 @@ describe('MockInterceptor - reply options callback', () => {
     }))
 
     t.throws(() => mockPool.dispatch({
-      path: '/test',
+      path: '/test-return-undefined',
+      method: 'GET'
+    }, {
+      onHeaders: () => { },
+      onData: () => { },
+      onComplete: () => { }
+    }), new InvalidArgumentError('reply options callback must return an object'))
+
+    t.throws(() => mockPool.dispatch({
+      path: '/test-return-null',
       method: 'GET'
     }, {
       onHeaders: () => { },