ownerslint.ts

import chalk from 'chalk';
import {readdirSync, readFileSync, statSync} from 'fs';
import {IMinimatch, Minimatch} from 'minimatch';
import {join} from 'path';

/**
 * Script that lints the CODEOWNERS file and makes sure that all files have an owner.
 */

/** Path for the Github owners file. */
const ownersFilePath = '.github/CODEOWNERS';

/** Path for the .gitignore file. */
const gitIgnorePath = '.gitignore';

let errors = 0;
const ownedPaths = readFileSync(ownersFilePath, 'utf8')
  .split('\n')
  // Trim lines.
  .map(line => line.trim())
  // Remove empty lines and comments.
  .filter(line => line && !line.startsWith('#'))
  // Split off just the path glob.
  .map(line => line.split(/\s+/)[0])
  // Turn paths into Minimatch objects.
  .map(path => new Minimatch(path, {dot: true, matchBase: true}));

const ignoredPaths = readFileSync(gitIgnorePath, 'utf8')
  .split('\n')
  // Trim lines.
  .map(line => line.trim())
  // Remove empty lines and comments.
  .filter(line => line && !line.startsWith('#'))
  // Turn paths into Minimatch objects.
  .map(path => new Minimatch(path, {dot: true, matchBase: true}));

for (let paths = getChildPaths('.'); paths.length; ) {
  paths = Array.prototype.concat(
    ...paths
      // Remove ignored paths
      .filter(
        path =>
          !ignoredPaths.reduce(
            (isIgnored, ignoredPath) => isIgnored || ignoredPath.match('/' + path),
            false,
          ),
      )
      // Remove paths that match an owned path.
      .filter(
        path =>
          !ownedPaths.reduce((isOwned, ownedPath) => isOwned || isOwnedBy(path, ownedPath), false),
      )
      // Report an error for any files that didn't match any owned paths.
      .filter(path => {
        if (statSync(path).isFile()) {
          console.log(chalk.red(`No code owner found for "${path}".`));
          errors++;
          return false;
        }
        return true;
      })
      // Get the next level of children for any directories.
      .map(path => getChildPaths(path)),
  );
}

if (errors) {
  throw Error(
    `Found ${errors} files with no owner. Code owners for the files ` +
      `should be added in the CODEOWNERS file.`,
  );
}

/** Check if the given path is owned by the given owned path matcher. */
function isOwnedBy(path: string, ownedPath: IMinimatch) {
  // If the owned path ends with `**` its safe to eliminate whole directories.
  if (ownedPath.pattern.endsWith('**') || statSync(path).isFile()) {
    return ownedPath.match('/' + path);
  }
  return false;
}

/** Get the immediate child paths of the given path. */
function getChildPaths(path: string) {
  return readdirSync(path).map(child => join(path, child));
}