angular-cli/packages/@angular/cli/tasks/lint.ts

const Task = require('../ember-cli/lib/models/task');
import * as chalk from 'chalk';
import * as path from 'path';
import * as glob from 'glob';
import * as ts from 'typescript';
import { requireProjectModule } from '../utilities/require-project-module';
import { CliConfig } from '../models/config';
import { LintCommandOptions } from '../commands/lint';
import { oneLine } from 'common-tags';

interface CliLintConfig {
  files?: (string | string[]);
  project?: string;
  tslintConfig?: string;
  exclude?: (string | string[]);
}

export default Task.extend({
  run: function (commandOptions: LintCommandOptions) {
    const ui = this.ui;
    const projectRoot = this.project.root;
    const lintConfigs: CliLintConfig[] = CliConfig.fromProject().config.lint || [];

    if (lintConfigs.length === 0) {
      ui.writeLine(chalk.yellow(oneLine`
        No lint config(s) found.
        If this is not intended, run "ng update".
      `));

      return Promise.resolve(0);
    }

    const tslint = requireProjectModule(projectRoot, 'tslint');
    const Linter = tslint.Linter;
    const Configuration = tslint.Configuration;

    let errors = 0;
    let results = '';

    lintConfigs
      .forEach((config) => {
        const program: ts.Program = Linter.createProgram(config.project);
        const files = getFilesToLint(program, config, Linter);

        const linter = new Linter({
          fix: commandOptions.fix,
          formatter: commandOptions.format
        }, program);

        files.forEach((file) => {
          const fileContents = program.getSourceFile(file).getFullText();
          const configLoad = Configuration.findConfiguration(config.tslintConfig, file);
          linter.lint(file, fileContents, configLoad.results);
        });

        const result = linter.getResult();
        errors += result.failureCount;
        results = results.concat(result.output.trim().concat('\n'));
      });

    if (errors > 0) {
      ui.writeLine(results.trim());
      ui.writeLine(chalk.red('Lint errors found in the listed files.'));
      return commandOptions.force ? Promise.resolve(0) : Promise.resolve(2);
    }

    ui.writeLine(chalk.green('All files pass linting.'));
    return Promise.resolve(0);
  }
});

function getFilesToLint(program: ts.Program, lintConfig: CliLintConfig, Linter: any): string[] {
  let files: string[] = [];

  if (lintConfig.files !== null) {
    files = Array.isArray(lintConfig.files) ? lintConfig.files : [lintConfig.files];
  } else {
    files = Linter.getFileNames(program);
  }

  let globOptions = {};

  if (lintConfig.exclude !== null) {
    const excludePatterns = Array.isArray(lintConfig.exclude)
      ? lintConfig.exclude
      : [lintConfig.exclude];

    globOptions = { ignore: excludePatterns, nodir: true };
  }

  files = files
    .map((file: string) => glob.sync(file, globOptions))
    .reduce((a: string[], b: string[]) => a.concat(b), []);

  return files;
}