Workaround for https://github.com/angular/angular-cli/issues/8412.

helpers.ts

export function fileExists(filePath: string) {
  return fs.existsSync(filePath);
}

export function readFile(filePath: string) {
  return fs.readFileSync(filePath).toString();
}

export function writeFile(filePath: string, contents: string, silent = false) {
  filePath = path.normalize(filePath);

  ensureDirectoryExists(filePath);

  fs.writeFileSync(filePath, contents);

  if (!silent) {
    console.log(`${filePath} written.`);
  }
}

export function ensureDirectoryExists(filePath: string) {
  const dirname = path.dirname(filePath);

  if (!fs.existsSync(dirname) || !fs.statSync(dirname).isDirectory()) {
    ensureDirectoryExists(dirname);
    fs.mkdirSync(dirname);
  }
}

patch-server-bundle.ts

// Super hacky hack. This is a workaround for https://github.com/angular/angular-cli/issues/8412.

import * as chokidar from 'chokidar';
import * as path from 'path';
import * as Lint from 'tslint';
import * as ts from 'typescript';

import { fileExists, readFile, writeFile } from './lib/helpers';

const invalidTypes = ['Document', 'Event', 'KeyboardEvent', 'MouseEvent'];

const serverBundleFilePath = path.resolve('./dist/server/main.bundle.js');

patchServerBundle();

const watcher = chokidar.watch(path.dirname(serverBundleFilePath), { persistent: true });
watcher.on('add', handleFileChange);
watcher.on('change', handleFileChange);

function handleFileChange(filePath: string) {
  if (path.resolve(filePath) === serverBundleFilePath) {
    patchServerBundle();
  }
}

function patchServerBundle() {
  if (fileExists(serverBundleFilePath)) {
    const serverBundleOriginalSource = readFile(serverBundleFilePath);
    const serverBundleSourceFile = ts.createSourceFile(serverBundleFilePath, serverBundleOriginalSource, ts.ScriptTarget.ES2015, true);
    const serverBundlePatchedSource = Lint.Replacement.applyFixes(serverBundleOriginalSource, walk(serverBundleSourceFile));

    if (serverBundleOriginalSource !== serverBundlePatchedSource) {
      writeFile(serverBundleFilePath, serverBundlePatchedSource);
    }
  }
}

function walk(sourceFile: ts.SourceFile) {
  const replacements: Lint.Replacement[] = [];

  ts.forEachChild(sourceFile, function visit(node) {
    if (ts.isCallExpression(node) && node.expression.getText() === '__metadata') {
      const types = node.arguments[1];

      if (ts.isArrayLiteralExpression(types)) {
        for (const element of types.elements) {
          if (invalidTypes.includes(element.getText())) {
            replacements.push(new Lint.Replacement(element.getStart(), element.getWidth(), 'Object'));
          }
        }
      }
    }

    ts.forEachChild(node, visit);
  });

  return replacements;
}