babel-minify/lib/index.js

✂️ An ES6+ aware minifier based on the Babel toolchain (beta)

"use strict";

const babelCore = require("@babel/core");

const babelPresetMinify = require("babel-preset-minify");

module.exports = function babelMinify(input, // Minify options passed to minifyPreset
// defaults are handled in preset
minifyOptions = {}, // overrides and other options
{
  minified = true,
  inputSourceMap,
  sourceMaps = false,
  sourceType = "script",
  comments = /^\**!|@preserve|@licen[sc]e|@cc_on/,
  // to override the default babelCore used
  babel = babelCore,
  // to override the default minify preset used
  minifyPreset = babelPresetMinify,
  // passthrough to babel
  filename,
  filenameRelative
} = {}) {
  return babel.transformSync(input, {
    babelrc: false,
    configFile: false,
    presets: [[minifyPreset, minifyOptions]],

    shouldPrintComment(contents) {
      return shouldPrintComment(contents, comments);
    },

    inputSourceMap,
    sourceMaps,
    minified,
    sourceType,
    filename,
    filenameRelative
  });
};

function shouldPrintComment(contents, predicate) {
  switch (typeof predicate) {
    case "function":
      return predicate(contents);

    case "object":
      return predicate.test(contents);

    default:
      return !!predicate;
  }
}