title: Angular 7 - change detection doesn't work with ngx-build-plus custom webpack configuration
body: <p>I am using <a href="https://github.com/manfredsteyer/ngx-build-plus" rel="nofollow noreferrer">ngx-build-plus</a> to customize build process for my Angular 7 app.<br>
  I have added <strong>webpack.partial.js</strong> file with following code:</p>
  
  <pre><code>const webpack = require('webpack');
  
  module.exports = {
    output: {
      jsonpFunction: 'header'
    },
    plugins: [
      new webpack.ProvidePlugin({
        Promise: 'es6-promise'
      })
    ]
  }
  </code></pre>
  
  <p>To run the app, I am using following command:</p>
  
  <pre><code>ng serve --extra-webpack-config webpack.extra.js -o
  </code></pre>
  
  <p>And here is my <strong>angular.json</strong></p>
  
  <pre><code>{
    "$schema": "./node_modules/@angular/cli/lib/config/schema.json",
    "version": 1,
    "newProjectRoot": "projects",
    "projects": {
      "header": {
        "root": "",
        "sourceRoot": "src",
        "projectType": "application",
        "prefix": "app",
        "schematics": {},
        "architect": {
          "build": {
            "builder": "ngx-build-plus:build",
            "options": {
              "outputPath": "dist/header",
              "index": "src/index.html",
              "main": "src/main.ts",
              "polyfills": "src/polyfills.ts",
              "tsConfig": "src/tsconfig.app.json",
              "assets": [
                "src/favicon.ico",
                "src/assets"
              ],
              "styles": [
                "node_modules/bootstrap/scss/bootstrap.scss",
                "src/styles.scss"
              ],
              "scripts": [
                "node_modules/jquery/dist/jquery.min.js",  
                "node_modules/popper.js/dist/umd/popper.min.js",  
                "node_modules/bootstrap/dist/js/bootstrap.min.js"
              ],
              "es5BrowserSupport": true
            },
            "configurations": {
              "production": {
                "fileReplacements": [
                  {
                    "replace": "src/environments/environment.ts",
                    "with": "src/environments/environment.prod.ts"
                  }
                ],
                "optimization": true,
                "outputHashing": "all",
                "sourceMap": false,
                "extractCss": true,
                "namedChunks": false,
                "aot": true,
                "extractLicenses": true,
                "vendorChunk": false,
                "buildOptimizer": true,
                "budgets": [
                  {
                    "type": "initial",
                    "maximumWarning": "2mb",
                    "maximumError": "5mb"
                  }
                ]
              },
              "en": {
                "aot": true,
                "i18nFile": "src/translate/messages.en.xlf",
                "i18nFormat": "xlf",
                "i18nLocale": "en",
                "i18nMissingTranslation": "error"
              },
              "fr": {
                "aot": true,
                "i18nFile": "src/translate/messages.fr.xlf",
                "i18nFormat": "xlf",
                "i18nLocale": "fr",
                "i18nMissingTranslation": "error"
              }
            }
          },
          "serve": {
            "builder": "ngx-build-plus:dev-server",
            "options": {
              "browserTarget": "header:build"
            },
            "configurations": {
              "production": {
                "browserTarget": "header:build:production"
              },
              "en": {
                "browserTarget": "header:build:en"
              },
              "fr": {
                "browserTarget": "header:build:fr"
              }
            }
          },
          "extract-i18n": {
            "builder": "@angular-devkit/build-angular:extract-i18n",
            "options": {
              "browserTarget": "header:build"
            }
          },
  
        }
      },
  
    },
    "defaultProject": "header",
    "schematics": {
      "@schematics/angular:component": {
        "styleext": "scss"
      }
    }
  }
  </code></pre>
  
  <p>The app works absolutely fine, if I run the app without custom config as follows:</p>
  
  <pre><code>ng serve
  </code></pre>
  
  <p>BUT, when I run app with custom webpack config, <strong>change detection</strong> does not work properly. A variable updated in component class does not get updated in template/view.  </p>
  
  <p>Whats wrong in using <strong>webpack.partial.js</strong></p>