feat(node): add source map support

closes #1072

packages/builders/package.json

@@ -33,6 +33,7 @@
     "identity-obj-proxy": "3.0.0",
     "license-webpack-plugin": "^1.4.0",
     "rxjs": "6.3.3",
+    "source-map-support": "0.5.11",
     "ts-loader": "5.3.1",
     "webpack": "4.29.0",
     "webpack-dev-server": "3.1.14",

packages/builders/src/utils/webpack/node.config.spec.ts

@@ -1,6 +1,7 @@
 import { getNodeWebpackConfig } from './node.config';
 import { getSystemPath, normalize } from '@angular-devkit/core';
 import { BuildNodeBuilderOptions } from '../../node/build/node-build.builder';
+import { BannerPlugin } from 'webpack';
 
 describe('getNodePartial', () => {
   let input: BuildNodeBuilderOptions;
@@ -84,4 +85,25 @@ describe('getNodePartial', () => {
       expect(result.externals).not.toBeDefined();
     });
   });
+
+  describe('the sourceMap option when true', () => {
+    it('should add a BannerPlugin', () => {
+      const result = getNodeWebpackConfig({
+        ...input,
+        sourceMap: true
+      });
+
+      const bannerPlugin = result.plugins.find(
+        plugin => plugin instanceof BannerPlugin
+      ) as BannerPlugin;
+      const options = (<any>bannerPlugin).options;
+
+      expect(bannerPlugin).toBeTruthy();
+      expect(options.banner).toEqual(
+        'require("source-map-support").install();'
+      );
+      expect(options.raw).toEqual(true);
+      expect(options.entryOnly).toEqual(false);
+    });
+  });
 });

packages/builders/src/utils/webpack/node.config.ts

@@ -1,4 +1,4 @@
-import { Configuration } from 'webpack';
+import { Configuration, BannerPlugin } from 'webpack';
 import * as mergeWebpack from 'webpack-merge';
 import * as nodeExternals from 'webpack-node-externals';
 
@@ -35,6 +35,16 @@ function getNodePartial(options: BuildNodeBuilderOptions) {
       }
     ];
   }
+
+  if (options.sourceMap) {
+    webpackConfig.plugins = [
+      new BannerPlugin({
+        banner: 'require("source-map-support").install();',
+        raw: true,
+        entryOnly: false
+      })
+    ];
+  }
   return webpackConfig;
 }