eslint-webpack-plugin/dist/index.js

A ESLint plugin for webpack

"use strict";

const {
  isAbsolute,
  join
} = require('path');
const {
  isMatch
} = require('micromatch');
const {
  getOptions
} = require('./options');
const linter = require('./linter');
const {
  arrify,
  parseFiles,
  parseFoldersToGlobs
} = require('./utils');

/** @typedef {import('webpack').Compiler} Compiler */
/** @typedef {import('webpack').Module} Module */
/** @typedef {import('webpack').NormalModule} NormalModule */
/** @typedef {import('./options').Options} Options */

const ESLINT_PLUGIN = 'ESLintWebpackPlugin';
const DEFAULT_FOLDER_TO_EXCLUDE = '**/node_modules/**';
let compilerId = 0;
class ESLintWebpackPlugin {
  /**
   * @param {Options} options
   */
  constructor(options = {}) {
    this.key = ESLINT_PLUGIN;
    this.options = getOptions(options);
    this.run = this.run.bind(this);
  }

  /**
   * @param {Compiler} compiler
   * @returns {void}
   */
  apply(compiler) {
    // Generate key for each compilation,
    // this differentiates one from the other when being cached.
    this.key = compiler.name || `${this.key}_${compilerId += 1}`;
    const excludedFiles = parseFiles(this.options.exclude || [], this.getContext(compiler));
    const resourceQueries = arrify(this.options.resourceQueryExclude || []);
    const excludedResourceQueries = resourceQueries.map(item => item instanceof RegExp ? item : new RegExp(item));
    const options = {
      ...this.options,
      exclude: excludedFiles,
      resourceQueryExclude: excludedResourceQueries,
      extensions: arrify(this.options.extensions),
      files: parseFiles(this.options.files || '', this.getContext(compiler))
    };
    const foldersToExclude = this.options.exclude ? options.exclude : DEFAULT_FOLDER_TO_EXCLUDE;
    const exclude = parseFoldersToGlobs(foldersToExclude);
    const wanted = parseFoldersToGlobs(options.files, options.extensions);

    // If `lintDirtyModulesOnly` is disabled,
    // execute the linter on the build
    if (!this.options.lintDirtyModulesOnly) {
      compiler.hooks.run.tapPromise(this.key, c => this.run(c, options, wanted, exclude));
    }
    let hasCompilerRunByDirtyModule = this.options.lintDirtyModulesOnly;
    compiler.hooks.watchRun.tapPromise(this.key, c => {
      if (!hasCompilerRunByDirtyModule) return this.run(c, options, wanted, exclude);
      hasCompilerRunByDirtyModule = false;
      return Promise.resolve();
    });
  }

  /**
   * @param {Compiler} compiler
   * @param {Omit<Options, 'resourceQueryExclude'> & {resourceQueryExclude: RegExp[]}} options
   * @param {string[]} wanted
   * @param {string[]} exclude
   */
  async run(compiler, options, wanted, exclude) {
    const isCompilerHooked = compiler.hooks.compilation.taps.find(({
      name
    }) => name === this.key);
    if (isCompilerHooked) return;
    compiler.hooks.compilation.tap(this.key, async compilation => {
      /** @type {import('./linter').Linter} */
      let lint;
      /** @type {import('./linter').Reporter} */
      let report;
      /** @type number */
      let threads;
      try {
        ({
          lint,
          report,
          threads
        } = await linter(this.key, options, compilation));
      } catch (e) {
        compilation.errors.push(e);
        return;
      }

      /** @type {string[]} */
      const files = [];

      // Add the file to be linted
      compilation.hooks.succeedModule.tap(this.key, addFile);
      if (!this.options.lintDirtyModulesOnly) {
        compilation.hooks.stillValidModule.tap(this.key, addFile);
      }

      /**
       * @param {Module} module
       */
      function addFile(module) {
        const {
          resource
        } = /** @type {NormalModule} */module;
        if (!resource) return;
        const [file, query] = resource.split('?');
        const isFileNotListed = file && !files.includes(file);
        const isFileWanted = isMatch(file, wanted, {
          dot: true
        }) && !isMatch(file, exclude, {
          dot: true
        });
        const isQueryNotExclude = options.resourceQueryExclude.every(reg => !reg.test(query));
        if (isFileNotListed && isFileWanted && isQueryNotExclude) {
          files.push(file);
          if (threads > 1) lint(file);
        }
      }

      // Lint all files added
      compilation.hooks.finishModules.tap(this.key, () => {
        if (files.length > 0 && threads <= 1) lint(files);
      });

      // await and interpret results
      compilation.hooks.additionalAssets.tapAsync(this.key, async function (callback) {
        const {
          errors,
          warnings,
          generateReportAsset
        } = await report();
        if (warnings) {
          // @ts-ignore
          compilation.warnings.push(warnings);
        }
        if (errors) {
          // @ts-ignore
          compilation.errors.push(errors);
        }
        if (generateReportAsset) {
          await generateReportAsset(compilation);
        }
        if (warnings && options.failOnWarning) {
          callback(warnings);
        } else if (errors && options.failOnError) {
          callback(errors);
        } else {
          callback();
        }
      });
    });
  }

  /**
   *
   * @param {Compiler} compiler
   * @returns {string}
   */
  getContext(compiler) {
    const compilerContext = String(compiler.options.context);
    const optionContext = this.options.context;
    if (!optionContext) return compilerContext;
    if (isAbsolute(optionContext)) return optionContext;
    return join(compilerContext, optionContext);
  }
}
module.exports = ESLintWebpackPlugin;