terser-webpack-plugin/dist/minify.js

"use strict";

const {
  minify: terserMinify
} = require('terser');
/** @typedef {import("source-map").RawSourceMap} RawSourceMap */

/** @typedef {import("./index.js").ExtractCommentsOptions} ExtractCommentsOptions */

/** @typedef {import("./index.js").CustomMinifyFunction} CustomMinifyFunction */

/** @typedef {import("./index.js").MinifyOptions} MinifyOptions */

/** @typedef {import("terser").MinifyOptions} TerserMinifyOptions */

/** @typedef {import("terser").MinifyOutput} MinifyOutput */

/** @typedef {import("terser").FormatOptions} FormatOptions */

/** @typedef {import("terser").MangleOptions} MangleOptions */

/** @typedef {import("./index.js").ExtractCommentsFunction} ExtractCommentsFunction */

/** @typedef {import("./index.js").ExtractCommentsCondition} ExtractCommentsCondition */

/**
 * @typedef {Object} InternalMinifyOptions
 * @property {string} name
 * @property {string} input
 * @property {RawSourceMap} inputSourceMap
 * @property {ExtractCommentsOptions} extractComments
 * @property {CustomMinifyFunction} minify
 * @property {MinifyOptions} minifyOptions
 */

/**
 * @typedef {Array<string>} ExtractedComments
 */

/**
 * @typedef {Promise<MinifyOutput & { extractedComments?: ExtractedComments}>} InternalMinifyResult
 */

/**
 * @typedef {TerserMinifyOptions & { sourceMap: undefined } & ({ output: FormatOptions & { beautify: boolean } } | { format: FormatOptions & { beautify: boolean } })} NormalizedTerserMinifyOptions
 */

/**
 * @param {TerserMinifyOptions} [terserOptions={}]
 * @returns {NormalizedTerserMinifyOptions}
 */


function buildTerserOptions(terserOptions = {}) {
  return { ...terserOptions,
    mangle: terserOptions.mangle == null ? true : typeof terserOptions.mangle === 'boolean' ? terserOptions.mangle : { ...terserOptions.mangle
    },
    // Ignoring sourceMap from options
    // eslint-disable-next-line no-undefined
    sourceMap: undefined,
    // the `output` option is deprecated
    ...(terserOptions.format ? {
      format: {
        beautify: false,
        ...terserOptions.format
      }
    } : {
      output: {
        beautify: false,
        ...terserOptions.output
      }
    })
  };
}
/**
 * @param {any} value
 * @returns {boolean}
 */


function isObject(value) {
  const type = typeof value;
  return value != null && (type === 'object' || type === 'function');
}
/**
 * @param {ExtractCommentsOptions} extractComments
 * @param {NormalizedTerserMinifyOptions} terserOptions
 * @param {ExtractedComments} extractedComments
 * @returns {ExtractCommentsFunction}
 */


function buildComments(extractComments, terserOptions, extractedComments) {
  /** @type {{ [index: string]: ExtractCommentsCondition }} */
  const condition = {};
  let comments;

  if (terserOptions.format) {
    ({
      comments
    } = terserOptions.format);
  } else if (terserOptions.output) {
    ({
      comments
    } = terserOptions.output);
  }

  condition.preserve = typeof comments !== 'undefined' ? comments : false;

  if (typeof extractComments === 'boolean' && extractComments) {
    condition.extract = 'some';
  } else if (typeof extractComments === 'string' || extractComments instanceof RegExp) {
    condition.extract = extractComments;
  } else if (typeof extractComments === 'function') {
    condition.extract = extractComments;
  } else if (extractComments && isObject(extractComments)) {
    condition.extract = typeof extractComments.condition === 'boolean' && extractComments.condition ? 'some' : typeof extractComments.condition !== 'undefined' ? extractComments.condition : 'some';
  } else {
    // No extract
    // Preserve using "commentsOpts" or "some"
    condition.preserve = typeof comments !== 'undefined' ? comments : 'some';
    condition.extract = false;
  } // Ensure that both conditions are functions


  ['preserve', 'extract'].forEach(key => {
    /** @type {undefined | string} */
    let regexStr;
    /** @type {undefined | RegExp} */

    let regex;

    switch (typeof condition[key]) {
      case 'boolean':
        condition[key] = condition[key] ? () => true : () => false;
        break;

      case 'function':
        break;

      case 'string':
        if (condition[key] === 'all') {
          condition[key] = () => true;

          break;
        }

        if (condition[key] === 'some') {
          condition[key] =
          /** @type {ExtractCommentsFunction} */
          (astNode, comment) => {
            return (comment.type === 'comment2' || comment.type === 'comment1') && /@preserve|@lic|@cc_on|^\**!/i.test(comment.value);
          };

          break;
        }

        regexStr =
        /** @type {string} */
        condition[key];

        condition[key] =
        /** @type {ExtractCommentsFunction} */
        (astNode, comment) => {
          return new RegExp(
          /** @type {string} */
          regexStr).test(comment.value);
        };

        break;

      default:
        regex =
        /** @type {RegExp} */
        condition[key];

        condition[key] =
        /** @type {ExtractCommentsFunction} */
        (astNode, comment) =>
        /** @type {RegExp} */
        regex.test(comment.value);

    }
  }); // Redefine the comments function to extract and preserve
  // comments according to the two conditions

  return (astNode, comment) => {
    if (
    /** @type {{ extract: ExtractCommentsFunction }} */
    condition.extract(astNode, comment)) {
      const commentText = comment.type === 'comment2' ? `/*${comment.value}*/` : `//${comment.value}`; // Don't include duplicate comments

      if (!extractedComments.includes(commentText)) {
        extractedComments.push(commentText);
      }
    }

    return (
      /** @type {{ preserve: ExtractCommentsFunction }} */
      condition.preserve(astNode, comment)
    );
  };
}
/**
 * @param {InternalMinifyOptions} options
 * @returns {InternalMinifyResult}
 */


async function minify(options) {
  const {
    name,
    input,
    inputSourceMap,
    minify: minifyFn,
    minifyOptions
  } = options;

  if (minifyFn) {
    return minifyFn({
      [name]: input
    }, inputSourceMap, minifyOptions);
  } // Copy terser options


  const terserOptions = buildTerserOptions(minifyOptions); // Let terser generate a SourceMap

  if (inputSourceMap) {
    // @ts-ignore
    terserOptions.sourceMap = {
      asObject: true
    };
  }
  /** @type {ExtractedComments} */


  const extractedComments = [];
  const {
    extractComments
  } = options;

  if (terserOptions.output) {
    terserOptions.output.comments = buildComments(extractComments, terserOptions, extractedComments);
  } else if (terserOptions.format) {
    terserOptions.format.comments = buildComments(extractComments, terserOptions, extractedComments);
  }

  const result = await terserMinify({
    [name]: input
  }, terserOptions);
  return { ...result,
    extractedComments
  };
}
/**
 * @param {string} options
 * @returns {InternalMinifyResult}
 */


function transform(options) {
  // 'use strict' => this === undefined (Clean Scope)
  // Safer for possible security issues, albeit not critical at all here
  // eslint-disable-next-line no-param-reassign
  const evaluatedOptions =
  /** @type {InternalMinifyOptions} */
  // eslint-disable-next-line no-new-func
  new Function('exports', 'require', 'module', '__filename', '__dirname', `'use strict'\nreturn ${options}`)(exports, require, module, __filename, __dirname);
  return minify(evaluatedOptions);
}

module.exports.minify = minify;
module.exports.transform = transform;