start.action.ts

import * as chalk from 'chalk';
import { spawn } from 'child_process';
import * as fs from 'fs';
import { join } from 'path';
import * as killProcess from 'tree-kill';
import { Input } from '../commands';
import { getValueOrDefault } from '../lib/compiler/helpers/get-value-or-default';
import { Configuration } from '../lib/configuration';
import { defaultOutDir } from '../lib/configuration/defaults';
import { ERROR_PREFIX } from '../lib/ui';
import { BuildAction } from './build.action';

export class StartAction extends BuildAction {
  public async handle(inputs: Input[], options: Input[]) {
    try {
      const configFileName = options.find((option) => option.name === 'config')!
        .value as string;
      const configuration = await this.loader.load(configFileName);
      const appName = inputs.find((input) => input.name === 'app')!
        .value as string;

      const pathToTsconfig = getValueOrDefault<string>(
        configuration,
        'compilerOptions.tsConfigPath',
        appName,
        'path',
        options,
      );

      const binaryToRunOption = options.find(
        (option) => option.name === 'exec',
      );
      const debugModeOption = options.find((option) => option.name === 'debug');
      const watchModeOption = options.find((option) => option.name === 'watch');
      const isWatchEnabled = !!(watchModeOption && watchModeOption.value);
      const watchAssetsModeOption = options.find(
        (option) => option.name === 'watchAssets',
      );
      const isWatchAssetsEnabled = !!(
        watchAssetsModeOption && watchAssetsModeOption.value
      );
      const debugFlag = debugModeOption && debugModeOption.value;
      const binaryToRun =
        binaryToRunOption && (binaryToRunOption.value as string | undefined);

      const { options: tsOptions } =
        this.tsConfigProvider.getByConfigFilename(pathToTsconfig);
      const outDir = tsOptions.outDir || defaultOutDir;
      const onSuccess = this.createOnSuccessHook(
        configuration,
        appName,
        debugFlag,
        outDir,
        binaryToRun,
      );

      await this.runBuild(
        inputs,
        options,
        isWatchEnabled,
        isWatchAssetsEnabled,
        !!debugFlag,
        onSuccess,
      );
    } catch (err) {
      if (err instanceof Error) {
        console.log(`\n${ERROR_PREFIX} ${err.message}\n`);
      } else {
        console.error(`\n${chalk.red(err)}\n`);
      }
    }
  }

  public createOnSuccessHook(
    configuration: Required<Configuration>,
    appName: string,
    debugFlag: boolean | string | undefined,
    outDirName: string,
    binaryToRun = 'node',
  ) {
    const sourceRoot = getValueOrDefault(configuration, 'sourceRoot', appName);
    const entryFile = getValueOrDefault(configuration, 'entryFile', appName);

    let childProcessRef: any;
    process.on(
      'exit',
      () => childProcessRef && killProcess(childProcessRef.pid),
    );

    return () => {
      if (childProcessRef) {
        childProcessRef.removeAllListeners('exit');
        childProcessRef.on('exit', () => {
          childProcessRef = this.spawnChildProcess(
            entryFile,
            sourceRoot,
            debugFlag,
            outDirName,
            binaryToRun,
          );
          childProcessRef.on('exit', () => (childProcessRef = undefined));
        });

        childProcessRef.stdin && childProcessRef.stdin.pause();
        killProcess(childProcessRef.pid);
      } else {
        childProcessRef = this.spawnChildProcess(
          entryFile,
          sourceRoot,
          debugFlag,
          outDirName,
          binaryToRun,
        );
        childProcessRef.on('exit', (code: number) => {
          process.exitCode = code;
          childProcessRef = undefined;
        });
      }
    };
  }

  private spawnChildProcess(
    entryFile: string,
    sourceRoot: string,
    debug: boolean | string | undefined,
    outDirName: string,
    binaryToRun: string,
  ) {
    let outputFilePath = join(outDirName, sourceRoot, entryFile);
    if (!fs.existsSync(outputFilePath + '.js')) {
      outputFilePath = join(outDirName, entryFile);
    }

    let childProcessArgs: string[] = [];
    const argsStartIndex = process.argv.indexOf('--');
    if (argsStartIndex >= 0) {
      childProcessArgs = process.argv.slice(argsStartIndex + 1);
    }
    outputFilePath =
      outputFilePath.indexOf(' ') >= 0 ? `"${outputFilePath}"` : outputFilePath;

    const processArgs = [outputFilePath, ...childProcessArgs];
    if (debug) {
      const inspectFlag =
        typeof debug === 'string' ? `--inspect=${debug}` : '--inspect';
      processArgs.unshift(inspectFlag);
    }
    if (this.isSourceMapSupportPkgAvailable()) {
      processArgs.unshift('-r source-map-support/register');
    }
    return spawn(binaryToRun, processArgs, {
      stdio: 'inherit',
      shell: true,
    });
  }

  private isSourceMapSupportPkgAvailable() {
    try {
      require.resolve('source-map-support');
      return true;
    } catch {
      return false;
    }
  }
}