index.js

var _ = require('lodash');
var Promise = require('bluebird');
var path = require('path');
var globAsync = Promise.promisify(require('glob'));
var fs = Promise.promisifyAll(require('fs-extra'));
var dir = Promise.promisifyAll(require('node-dir'));
var minimatch = require('minimatch');
var loaderUtils = require("loader-utils");

function toLooksLikeDirectory(pattern) {
  var filename = pattern.to;
  if ((path.extname(filename) === '' || // doesn't have an extension
    _.last(filename) === path.sep ||    // ends in a path separator
    _.last(filename) === '/' ||         // ends in a slash (kept for compatibility)
    pattern.toType === 'dir') &&        // is explicitly a dir
    pattern.toType !== 'file') {        // is not explicitly a file
    return true;
  }
}

function apply(patterns, opts, compiler) {

  var baseDir = compiler.options.context;
  var fileDependencies = [];
  var contextDependencies = [];
  var lastGlobalUpdate = 0;

  if (!opts) {
    opts = {};
  }

  var ignoreList = opts.ignore,
      namePattern = opts.namePattern;

  compiler.plugin('emit', function(compilation, cb) {
    Promise.each(patterns, function(pattern) {
      var relSrc = pattern.from;
      var absSrc = path.resolve(baseDir, relSrc);
      var relDest = pattern.to || '';
      
      var forceWrite = !!pattern.force;

      return fs.statAsync(absSrc)
      .catch(function(err) {
        return null;
      })
      .then(function(stat) {
        if (stat && stat.isDirectory()) {
          contextDependencies.push(absSrc);
          
          // Make the relative destination actually relative
          if (path.isAbsolute(relDest)) {
            relDest = path.relative(baseDir, relDest);
          }
          
          return writeDirectoryToAssets({
            compilation: compilation,
            absDirSrc: absSrc,
            relDirDest: relDest,
            forceWrite: forceWrite,
            lastGlobalUpdate: lastGlobalUpdate,
            ignoreList: ignoreList,
            namePattern: namePattern,
          });
        } else {

          return globAsync(relSrc, {cwd: baseDir})
          .each(function(relFileSrc) {
                 
            // Skip if it matches any of our ignore list
            if (shouldIgnore(relFileSrc, ignoreList)) {
              return;
            }

            var absFileSrc = path.resolve(baseDir, relFileSrc);
            var relFileDest = pattern.to || '';
            var relFileDirname = path.dirname(relFileSrc);

            fileDependencies.push(absFileSrc);
            
            if (!stat && relFileDirname !== baseDir) {
              if (path.isAbsolute(relFileSrc)) {
                // If the file is in a subdirectory (from globbing), we should correctly map the dest folder
                relFileDest = path.join(path.relative(baseDir, relFileDirname), path.basename(relFileSrc));
              } else {
                relFileDest = relFileSrc;
              }
            } else if (toLooksLikeDirectory(pattern)) {
              relFileDest = path.join(relFileDest, path.basename(relFileSrc));
            } else {
              relFileDest = relFileDest || path.basename(relFileSrc);
            }
            
            // Make the relative destination actually relative
            if (path.isAbsolute(relFileDest)) {
              relFileDest = path.relative(baseDir, relFileDest);
            }

            return writeFileToAssets({
              compilation: compilation,
              absFileSrc: absFileSrc,
              relFileDest: relFileDest,
              forceWrite: forceWrite,
              lastGlobalUpdate: lastGlobalUpdate,
              namePattern: namePattern,
            });
          });
        }
      });
    })
    .then(function() {
      lastGlobalUpdate = _.now();
    })
    .catch(function(err) {
      compilation.errors.push(err);
    })
    .finally(cb);
  });

  compiler.plugin("after-emit", function(compilation, cb) {
    var trackedFiles = compilation.fileDependencies;
    _.each(fileDependencies, function(file) {
      if (!_.includes(trackedFiles, file)) {
        trackedFiles.push(file);
      }
    });

    var trackedDirs = compilation.contextDependencies;
    _.each(contextDependencies, function(context) {
      if (!_.includes(trackedDirs, context)) {
        trackedDirs.push(context);
      }
    });

    cb();
  });
}

function getDestName(relFileDest, namePattern) {
    if (!namePattern) {
      return relFileDest;
    }

    var ext = path.extname(relFileDest);
    relFileDest = relFileDest.replace(ext, "");
    return namePattern.replace("[name]", relFileDest);
}

function writeFileToAssets(opts) {
  var compilation = opts.compilation;
  var relFileDest = opts.relFileDest;
  var absFileSrc = opts.absFileSrc;
  var forceWrite = opts.forceWrite;
  var lastGlobalUpdate = opts.lastGlobalUpdate;
  var namePattern = opts.namePattern;

  if (compilation.assets[relFileDest] && !forceWrite) {
    return Promise.resolve();
  }

  return fs.statAsync(absFileSrc)
  .then(function(stat) {
    if (stat.mtime.getTime() > lastGlobalUpdate) {
      
      var relFileDestHash = getDestName(relFileDest, namePattern).replace(/\[(?:(\w+):)?contenthash(?::([a-z]+\d*))?(?::(\d+))?\]/ig, function() {
          return loaderUtils.getHashDigest(fs.readFileSync(absFileSrc), null, null, parseInt(6, 10));
      });

      compilation.assets[relFileDestHash] = {
        size: function() {
          return stat.size;
        },
        source: function() {
          return fs.readFileSync(absFileSrc);
        },
        chunk: relFileDest,
      };
    }
  });
}

function writeDirectoryToAssets(opts) {
  var compilation = opts.compilation;
  var absDirSrc = opts.absDirSrc;
  var relDirDest = opts.relDirDest;
  var forceWrite = opts.forceWrite;
  var lastGlobalUpdate = opts.lastGlobalUpdate;
  var ignoreList = opts.ignoreList;
  var namePattern = opts.namePattern;

  return dir.filesAsync(absDirSrc)
  .each(function(absFileSrc) {
    var relFileSrc = path.relative(absDirSrc, absFileSrc);
    var relFileDest = path.join(relDirDest, relFileSrc);

    // Skip if it matches any of our ignore list
    if (shouldIgnore(relFileSrc, ignoreList)) {
      return;
    }

    // Make sure it doesn't start with the separator
    if (_.first(relFileDest) === path.sep) {
      relFileDest = relFileDest.slice(1);
    }

    return writeFileToAssets({
      compilation: compilation,
      absFileSrc: absFileSrc,
      relFileDest: relFileDest,
      forceWrite: forceWrite,
      lastGlobalUpdate: lastGlobalUpdate,
      namePattern: namePattern
    });
  });
}

function shouldIgnore(pathName, ignoreList) {
  var matched = _.find(ignoreList, function(g) {
    // Default minimatch params
    var params = {
      matchBase: true
    };
    
    var glob;
    if (_.isString(g)) {
      glob = g;
    } else if(_.isObject(g)){
      glob = g.glob || '';
      // Overwrite minimatch defaults
      params = _.assign(params, _.omit(g, ['glob']));
    } else {
      glob = '';
    }
    
    return minimatch(pathName, glob, params);
  });
  if (matched) {
    return true;
  } else {
    return false;
  }
}

module.exports = function(patterns, options) {
  if (_.isUndefined(patterns)) {
    patterns = [];
  }

  if (!_.isArray(patterns)) {
    throw new Error('CopyWebpackPlugin: patterns must be an array');
  }

  return {
    apply: apply.bind(this, patterns, options)
  };
};