fix(deps): drop dependency on through2 (#388)

Author: JustinBeckwith

packages/google-cloud-dialogflow/package.json

@@ -60,7 +60,6 @@
     "nyc": "^14.0.0",
     "power-assert": "^1.4.4",
     "prettier": "^1.7.4",
-    "through2": "^3.0.0",
     "linkinator": "^1.5.0"
   }
 }

packages/google-cloud-dialogflow/samples/package.json

@@ -9,16 +9,14 @@
     "resources"
   ],
   "engines": {
-    "node": ">=8.0.0"
+    "node": ">=10.0.0"
   },
   "scripts": {
     "test": "mocha system-test --timeout=600000"
   },
   "dependencies": {
     "dialogflow": "^0.10.2",
     "pb-util": "^0.1.0",
-    "pump": "^3.0.0",
-    "through2": "^3.0.0",
     "uuid": "^3.3.2",
     "yargs": "^13.0.0"
   },

packages/google-cloud-dialogflow/test/gapic-v2.js

@@ -15,7 +15,7 @@
 'use strict';
 
 const assert = require('assert');
-const through2 = require('through2');
+const {PassThrough} = require('stream');
 
 const dialogflowModule = require('../src');
 
@@ -2818,13 +2818,16 @@ function mockSimpleGrpcMethod(expectedRequest, response, error) {
 
 function mockBidiStreamingGrpcMethod(expectedRequest, response, error) {
   return () => {
-    const mockStream = through2.obj((chunk, enc, callback) => {
-      assert.deepStrictEqual(chunk, expectedRequest);
-      if (error) {
-        callback(error);
-      } else {
-        callback(null, response);
-      }
+    const mockStream = new PassThrough({
+      objectMode: true,
+      transform: (chunk, enc, callback) => {
+        assert.deepStrictEqual(chunk, expectedRequest);
+        if (error) {
+          callback(error);
+        } else {
+          callback(null, response);
+        }
+      },
     });
     return mockStream;
   };

packages/google-cloud-dialogflow/test/gapic-v2beta1.js

@@ -15,7 +15,7 @@
 'use strict';
 
 const assert = require('assert');
-const through2 = require('through2');
+const {PassThrough} = require('stream');
 
 const dialogflowModule = require('../src');
 
@@ -3697,13 +3697,16 @@ function mockSimpleGrpcMethod(expectedRequest, response, error) {
 
 function mockBidiStreamingGrpcMethod(expectedRequest, response, error) {
   return () => {
-    const mockStream = through2.obj((chunk, enc, callback) => {
-      assert.deepStrictEqual(chunk, expectedRequest);
-      if (error) {
-        callback(error);
-      } else {
-        callback(null, response);
-      }
+    const mockStream = new PassThrough({
+      objectMode: true,
+      transform: (chunk, enc, callback) => {
+        assert.deepStrictEqual(chunk, expectedRequest);
+        if (error) {
+          callback(error);
+        } else {
+          callback(null, response);
+        }
+      },
     });
     return mockStream;
   };