electron/script/lint.js

#!/usr/bin/env node

const crypto = require('node:crypto');
const { GitProcess } = require('dugite');
const childProcess = require('node:child_process');
const { ESLint } = require('eslint');
const fs = require('node:fs');
const minimist = require('minimist');
const path = require('node:path');
const { getCodeBlocks } = require('@electron/lint-roller/dist/lib/markdown');

const { chunkFilenames, findMatchingFiles } = require('./lib/utils');

const ELECTRON_ROOT = path.normalize(path.dirname(__dirname));
const SOURCE_ROOT = path.resolve(ELECTRON_ROOT, '..');
const DEPOT_TOOLS = path.resolve(SOURCE_ROOT, 'third_party', 'depot_tools');

// Augment the PATH for this script so that we can find executables
// in the depot_tools folder even if folks do not have an instance of
// DEPOT_TOOLS in their path already
process.env.PATH = `${process.env.PATH}${path.delimiter}${DEPOT_TOOLS}`;

const IGNORELIST = new Set(
  [
    ['shell', 'browser', 'resources', 'win', 'resource.h'],
    ['shell', 'common', 'node_includes.h'],
    ['spec', 'fixtures', 'pages', 'jquery-3.6.0.min.js']
  ].map((tokens) => path.join(ELECTRON_ROOT, ...tokens))
);

const IS_WINDOWS = process.platform === 'win32';

const CPPLINT_FILTERS = [
  // from presubmit_canned_checks.py OFF_BY_DEFAULT_LINT_FILTERS
  '-build/include',
  '-build/include_order',
  '-build/namespaces',
  '-readability/casting',
  '-runtime/int',
  '-whitespace/braces',
  // from presubmit_canned_checks.py OFF_UNLESS_MANUALLY_ENABLED_LINT_FILTERS
  '-build/c++11',
  '-build/header_guard',
  '-readability/todo',
  '-runtime/references',
  '-whitespace/braces',
  '-whitespace/comma',
  '-whitespace/end_of_line',
  '-whitespace/forcolon',
  '-whitespace/indent',
  '-whitespace/line_length',
  '-whitespace/newline',
  '-whitespace/operators',
  '-whitespace/parens',
  '-whitespace/semicolon',
  '-whitespace/tab'
];

function spawnAndCheckExitCode (cmd, args, opts) {
  opts = { stdio: 'inherit', ...opts };
  const { error, status, signal } = childProcess.spawnSync(cmd, args, opts);
  if (error) {
    // the subprocess failed or timed out
    console.error(error);
    process.exit(1);
  }
  if (status === null) {
    // the subprocess terminated due to a signal
    console.error(signal);
    process.exit(1);
  }
  if (status !== 0) {
    // `status` is an exit code
    process.exit(status);
  }
}

function cpplint (args) {
  args.unshift(`--root=${SOURCE_ROOT}`);
  const result = childProcess.spawnSync(
    IS_WINDOWS ? 'cpplint.bat' : 'cpplint.py',
    args,
    { encoding: 'utf8', shell: true }
  );
  // cpplint.py writes EVERYTHING to stderr, including status messages
  if (result.stderr) {
    for (const line of result.stderr.split(/[\r\n]+/)) {
      if (
        line.length &&
        !line.startsWith('Done processing ') &&
        line !== 'Total errors found: 0'
      ) {
        console.warn(line);
      }
    }
  }
  if (result.status !== 0) {
    if (result.error) console.error(result.error);
    process.exit(result.status || 1);
  }
}

function isObjCHeader (filename) {
  return /\/(mac|cocoa)\//.test(filename);
}

const LINTERS = [
  {
    key: 'cpp',
    roots: ['shell'],
    test: (filename) =>
      filename.endsWith('.cc') ||
      (filename.endsWith('.h') && !isObjCHeader(filename)),
    run: (opts, filenames) => {
      const clangFormatFlags = opts.fix ? ['--fix'] : [];
      for (const chunk of chunkFilenames(filenames)) {
        spawnAndCheckExitCode('python3', [
          'script/run-clang-format.py',
          ...clangFormatFlags,
          ...chunk
        ]);
        cpplint([`--filter=${CPPLINT_FILTERS.join(',')}`, ...chunk]);
      }
    }
  },
  {
    key: 'objc',
    roots: ['shell'],
    test: (filename) =>
      filename.endsWith('.mm') ||
      (filename.endsWith('.h') && isObjCHeader(filename)),
    run: (opts, filenames) => {
      const clangFormatFlags = opts.fix ? ['--fix'] : [];
      spawnAndCheckExitCode('python3', [
        'script/run-clang-format.py',
        '-r',
        ...clangFormatFlags,
        ...filenames
      ]);
      const filter = [...CPPLINT_FILTERS, '-readability/braces'];
      cpplint([
        '--extensions=mm,h',
        `--filter=${filter.join(',')}`,
        ...filenames
      ]);
    }
  },
  {
    key: 'python',
    roots: ['script'],
    test: (filename) => filename.endsWith('.py'),
    run: (opts, filenames) => {
      const rcfile = path.join(DEPOT_TOOLS, 'pylintrc');
      const args = ['--rcfile=' + rcfile, ...filenames];
      const env = {
        PYTHONPATH: path.join(ELECTRON_ROOT, 'script'),
        ...process.env
      };
      spawnAndCheckExitCode('pylint-2.7', args, { env });
    }
  },
  {
    key: 'javascript',
    roots: ['build', 'default_app', 'lib', 'npm', 'script', 'spec'],
    ignoreRoots: ['spec/node_modules'],
    test: (filename) => filename.endsWith('.js') || filename.endsWith('.ts'),
    run: async (opts, filenames) => {
      const eslint = new ESLint({
        // Do not use the lint cache on CI builds
        cache: !process.env.CI,
        cacheLocation: `node_modules/.eslintcache.${crypto
          .createHash('md5')
          .update(fs.readFileSync(__filename))
          .digest('hex')}`,
        extensions: ['.js', '.ts'],
        fix: opts.fix,
        overrideConfigFile: path.join(ELECTRON_ROOT, '.eslintrc.json'),
        resolvePluginsRelativeTo: ELECTRON_ROOT
      });
      const formatter = await eslint.loadFormatter();
      let successCount = 0;
      const results = await eslint.lintFiles(filenames);
      for (const result of results) {
        successCount += result.errorCount === 0 ? 1 : 0;
        if (
          opts.verbose &&
          result.errorCount === 0 &&
          result.warningCount === 0
        ) {
          console.log(`${result.filePath}: no errors or warnings`);
        }
      }
      console.log(formatter.format(results));
      if (opts.fix) {
        await ESLint.outputFixes(results);
      }
      if (successCount !== filenames.length) {
        console.error('Linting had errors');
        process.exit(1);
      }
    }
  },
  {
    key: 'gn',
    roots: ['.'],
    test: (filename) => filename.endsWith('.gn') || filename.endsWith('.gni'),
    run: (opts, filenames) => {
      const allOk = filenames
        .map((filename) => {
          const env = {
            CHROMIUM_BUILDTOOLS_PATH: path.resolve(
              ELECTRON_ROOT,
              '..',
              'buildtools'
            ),
            DEPOT_TOOLS_WIN_TOOLCHAIN: '0',
            ...process.env
          };
          // Users may not have depot_tools in PATH.
          env.PATH = `${env.PATH}${path.delimiter}${DEPOT_TOOLS}`;
          const args = ['format', filename];
          if (!opts.fix) args.push('--dry-run');
          const result = childProcess.spawnSync('gn', args, {
            env,
            stdio: 'inherit',
            shell: true
          });
          if (result.status === 0) {
            return true;
          } else if (result.status === 2) {
            console.log(
              `GN format errors in "${filename}". Run 'gn format "${filename}"' or rerun with --fix to fix them.`
            );
            return false;
          } else {
            console.log(
              `Error running 'gn format --dry-run "${filename}"': exit code ${result.status}`
            );
            return false;
          }
        })
        .every((x) => x);
      if (!allOk) {
        process.exit(1);
      }
    }
  },
  {
    key: 'patches',
    roots: ['patches'],
    test: (filename) => filename.endsWith('.patch'),
    run: (opts, filenames) => {
      const patchesDir = path.resolve(__dirname, '../patches');
      const patchesConfig = path.resolve(patchesDir, 'config.json');
      // If the config does not exist, that's a problem
      if (!fs.existsSync(patchesConfig)) {
        console.error(`Patches config file: "${patchesConfig}" does not exist`);
        process.exit(1);
      }

      for (const target of JSON.parse(fs.readFileSync(patchesConfig, 'utf8'))) {
        // The directory the config points to should exist
        const targetPatchesDir = path.resolve(__dirname, '../../..', target.patch_dir);
        if (!fs.existsSync(targetPatchesDir)) {
          console.error(
            `target patch directory: "${targetPatchesDir}" does not exist`
          );
          process.exit(1);
        }
        // We need a .patches file
        const dotPatchesPath = path.resolve(targetPatchesDir, '.patches');
        if (!fs.existsSync(dotPatchesPath)) {
          console.error(`.patches file: "${dotPatchesPath}" does not exist`);
          process.exit(1);
        }

        // Read the patch list
        const patchFileList = fs
          .readFileSync(dotPatchesPath, 'utf8')
          .trim()
          .split('\n');
        const patchFileSet = new Set(patchFileList);
        patchFileList.reduce((seen, file) => {
          if (seen.has(file)) {
            console.error(
              `'${file}' is listed in ${dotPatchesPath} more than once`
            );
            process.exit(1);
          }
          return seen.add(file);
        }, new Set());

        if (patchFileList.length !== patchFileSet.size) {
          console.error(
            'Each patch file should only be in the .patches file once'
          );
          process.exit(1);
        }

        for (const file of fs.readdirSync(targetPatchesDir)) {
          // Ignore the .patches file and READMEs
          if (file === '.patches' || file === 'README.md') continue;

          if (!patchFileSet.has(file)) {
            console.error(
              `Expected the .patches file at "${dotPatchesPath}" to contain a patch file ("${file}") present in the directory but it did not`
            );
            process.exit(1);
          }
          patchFileSet.delete(file);
        }

        // If anything is left in this set, it means it did not exist on disk
        if (patchFileSet.size > 0) {
          console.error(
            `Expected all the patch files listed in the .patches file at "${dotPatchesPath}" to exist but some did not:\n${JSON.stringify(
              [...patchFileSet.values()],
              null,
              2
            )}`
          );
          process.exit(1);
        }
      }

      const allOk =
        filenames.length > 0 &&
        filenames
          .map((f) => {
            const patchText = fs.readFileSync(f, 'utf8');
            const subjectAndDescription =
              /Subject: (.*?)\n\n([\s\S]*?)\s*(?=diff)/ms.exec(patchText);
            if (!subjectAndDescription[2]) {
              console.warn(
                `Patch file '${f}' has no description. Every patch must contain a justification for why the patch exists and the plan for its removal.`
              );
              return false;
            }
            const trailingWhitespaceLines = patchText
              .split(/\r?\n/)
              .map((line, index) => [line, index])
              .filter(([line]) => line.startsWith('+') && /\s+$/.test(line))
              .map(([, lineNumber]) => lineNumber + 1);
            if (trailingWhitespaceLines.length > 0) {
              console.warn(
                `Patch file '${f}' has trailing whitespace on some lines (${trailingWhitespaceLines.join(
                  ','
                )}).`
              );
              return false;
            }
            return true;
          })
          .every((x) => x);
      if (!allOk) {
        process.exit(1);
      }
    }
  },
  {
    key: 'md',
    roots: ['.'],
    ignoreRoots: ['node_modules', 'spec/node_modules'],
    test: (filename) => filename.endsWith('.md'),
    run: async (opts, filenames) => {
      let errors = false;

      // Run markdownlint on all Markdown files
      for (const chunk of chunkFilenames(filenames)) {
        spawnAndCheckExitCode('electron-markdownlint', chunk);
      }

      // Run the remaining checks only in docs
      const docs = filenames.filter(
        (filename) => path.dirname(filename).split(path.sep)[0] === 'docs'
      );

      for (const filename of docs) {
        const contents = fs.readFileSync(filename, 'utf8');
        const codeBlocks = await getCodeBlocks(contents);

        for (const codeBlock of codeBlocks) {
          const line = codeBlock.position.start.line;

          if (codeBlock.lang) {
            // Enforce all lowercase language identifiers
            if (codeBlock.lang.toLowerCase() !== codeBlock.lang) {
              console.log(
                `${filename}:${line} Code block language identifiers should be all lowercase`
              );
              errors = true;
            }

            // Prefer js/ts to javascript/typescript as the language identifier
            if (codeBlock.lang === 'javascript') {
              console.log(
                `${filename}:${line} Use 'js' as code block language identifier instead of 'javascript'`
              );
              errors = true;
            }

            if (codeBlock.lang === 'typescript') {
              console.log(
                `${filename}:${line} Use 'typescript' as code block language identifier instead of 'ts'`
              );
              errors = true;
            }

            // Enforce latest fiddle code block syntax
            if (
              codeBlock.lang === 'javascript' &&
              codeBlock.meta &&
              codeBlock.meta.includes('fiddle=')
            ) {
              console.log(
                `${filename}:${line} Use 'fiddle' as code block language identifier instead of 'javascript fiddle='`
              );
              errors = true;
            }

            // Ensure non-empty content in fiddle code blocks matches the file content
            if (codeBlock.lang === 'fiddle' && codeBlock.value.trim() !== '') {
              // This is copied and adapted from the website repo:
              // https://github.com/electron/website/blob/62a55ca0dd14f97339e1a361b5418d2f11c34a75/src/transformers/fiddle-embedder.ts#L89C6-L101
              const parseFiddleEmbedOptions = (optStrings) => {
                // If there are optional parameters, parse them out to pass to the getFiddleAST method.
                return optStrings.reduce((opts, option) => {
                  // Use indexOf to support bizarre combinations like `|key=Myvalue=2` (which will properly
                  // parse to {'key': 'Myvalue=2'})
                  const firstEqual = option.indexOf('=');
                  const key = option.slice(0, firstEqual);
                  const value = option.slice(firstEqual + 1);
                  return { ...opts, [key]: value };
                }, {});
              };

              const [dir, ...others] = codeBlock.meta.split('|');
              const options = parseFiddleEmbedOptions(others);

              const fiddleFilename = path.join(dir, options.focus || 'main.js');

              try {
                const fiddleContent = fs
                  .readFileSync(fiddleFilename, 'utf8')
                  .trim();

                if (fiddleContent !== codeBlock.value.trim()) {
                  console.log(
                    `${filename}:${line} Content for fiddle code block differs from content in ${fiddleFilename}`
                  );
                  errors = true;
                }
              } catch (err) {
                console.error(
                  `${filename}:${line} Error linting fiddle code block content`
                );
                if (err.stack) {
                  console.error(err.stack);
                }
                errors = true;
              }
            }
          }
        }
      }

      if (errors) {
        process.exit(1);
      }
    }
  }
];

function parseCommandLine () {
  let help;
  const langs = [
    'cpp',
    'objc',
    'javascript',
    'python',
    'gn',
    'patches',
    'markdown'
  ];
  const langRoots = langs.map((lang) => lang + '-roots');
  const langIgnoreRoots = langs.map((lang) => lang + '-ignore-roots');
  const opts = minimist(process.argv.slice(2), {
    boolean: [...langs, 'help', 'changed', 'fix', 'verbose', 'only'],
    alias: {
      cpp: ['c++', 'cc', 'cxx'],
      javascript: ['js', 'es'],
      python: 'py',
      markdown: 'md',
      changed: 'c',
      help: 'h',
      verbose: 'v'
    },
    string: [...langRoots, ...langIgnoreRoots],
    unknown: () => {
      help = true;
    }
  });
  if (help || opts.help) {
    const langFlags = langs.map((lang) => `[--${lang}]`).join(' ');
    console.log(
      `Usage: script/lint.js ${langFlags} [-c|--changed] [-h|--help] [-v|--verbose] [--fix] [--only -- file1 file2]`
    );
    process.exit(0);
  }
  return opts;
}

function populateLinterWithArgs (linter, opts) {
  const extraRoots = opts[`${linter.key}-roots`];
  if (extraRoots) {
    linter.roots.push(...extraRoots.split(','));
  }
  const extraIgnoreRoots = opts[`${linter.key}-ignore-roots`];
  if (extraIgnoreRoots) {
    const list = extraIgnoreRoots.split(',');
    if (linter.ignoreRoots) {
      linter.ignoreRoots.push(...list);
    } else {
      linter.ignoreRoots = list;
    }
  }
}

async function findChangedFiles (top) {
  const result = await GitProcess.exec(
    ['diff', '--name-only', '--cached'],
    top
  );
  if (result.exitCode !== 0) {
    console.log(
      'Failed to find changed files',
      GitProcess.parseError(result.stderr)
    );
    process.exit(1);
  }
  const relativePaths = result.stdout.split(/\r\n|\r|\n/g);
  const absolutePaths = relativePaths.map((x) => path.join(top, x));
  return new Set(absolutePaths);
}

async function findFiles (args, linter) {
  let filenames = [];
  let includelist = null;

  // build the includelist
  if (args.changed) {
    includelist = await findChangedFiles(ELECTRON_ROOT);
    if (!includelist.size) {
      return [];
    }
  } else if (args.only) {
    includelist = new Set(args._.map((p) => path.resolve(p)));
  }

  // accumulate the raw list of files
  for (const root of linter.roots) {
    const files = await findMatchingFiles(
      path.join(ELECTRON_ROOT, root),
      linter.test
    );
    filenames.push(...files);
  }

  for (const ignoreRoot of linter.ignoreRoots || []) {
    const ignorePath = path.join(ELECTRON_ROOT, ignoreRoot);
    if (!fs.existsSync(ignorePath)) continue;

    const ignoreFiles = new Set(
      await findMatchingFiles(ignorePath, linter.test)
    );
    filenames = filenames.filter((fileName) => !ignoreFiles.has(fileName));
  }

  // remove ignored files
  filenames = filenames.filter((x) => !IGNORELIST.has(x));

  // if a includelist exists, remove anything not in it
  if (includelist) {
    filenames = filenames.filter((x) => includelist.has(x));
  }

  // it's important that filenames be relative otherwise clang-format will
  // produce patches with absolute paths in them, which `git apply` will refuse
  // to apply.
  return filenames.map((x) => path.relative(ELECTRON_ROOT, x));
}

async function main () {
  const opts = parseCommandLine();

  // no mode specified? run 'em all
  if (
    !opts.cpp &&
    !opts.javascript &&
    !opts.objc &&
    !opts.python &&
    !opts.gn &&
    !opts.patches &&
    !opts.markdown
  ) {
    opts.cpp =
      opts.javascript =
      opts.objc =
      opts.python =
      opts.gn =
      opts.patches =
      opts.markdown =
        true;
  }

  const linters = LINTERS.filter((x) => opts[x.key]);

  for (const linter of linters) {
    populateLinterWithArgs(linter, opts);
    const filenames = await findFiles(opts, linter);
    if (filenames.length) {
      if (opts.verbose) {
        console.log(
          `linting ${filenames.length} ${linter.key} ${
            filenames.length === 1 ? 'file' : 'files'
          }`
        );
      }
      await linter.run(opts, filenames);
    }
  }
}

if (require.main === module) {
  main().catch((error) => {
    console.error(error);
    process.exit(1);
  });
}