persistify/index.js

a wrapper around `browserify` and `watchify` to make incremental builds without the need of the watch mode

var through = require( 'through2' );
var watchify = require( 'watchify' );
var trim = require( 'jq-trim' );

var parseAsRegex = function parseAsRegex( regex ) {
  if ( typeof regex === 'string' ) {
    return new RegExp( regex );
  }
  return regex;
};

module.exports = function ( browserifyOpts, opts, argv ) {
  browserifyOpts = browserifyOpts || { };
  opts = opts || { };
  var hash = require( 'hash-string' );

  var xtend = require( 'xtend' );

  var id = 'persistify_' + hash( process.cwd() + trim( opts.cacheId ) );
  var depsCacheId = 'deps-cx-' + id;
  var cacheDir = opts.cacheDir;

  var flatCache = require( 'flat-cache' );
  var fileEntryCache = require( 'file-entry-cache' );

  if ( opts.recreate ) {
    flatCache.clearCacheById( id, cacheDir );
    flatCache.clearCacheById( depsCacheId, cacheDir );
  }
  // load the cache with id
  var cache = flatCache.load( id, cacheDir );

  // load the file entry cache with id, or create a new
  // one if the previous one doesn't exist
  var depsCacheFile = fileEntryCache.create( depsCacheId, cacheDir );

  var ignoreCache = false;

  // if the command was specified this can be used
  // as the cache buster
  if ( opts.command ) {
    var configHashPersisted = cache.getKey( 'configHash' );
    var hashOfConfig = hash( opts.command );

    ignoreCache = configHashPersisted !== hashOfConfig;

    if ( ignoreCache ) {
      cache.setKey( 'configHash', hashOfConfig );
    }
  }

  var defaultCache = {
    cache: {},
    packageCache: {}
  };

  var persistifyCache = ignoreCache ? defaultCache : (cache.getKey( 'persistifyArgs' ) || defaultCache);

  browserifyOpts.cache = persistifyCache.cache;
  browserifyOpts.packageCache = persistifyCache.packageCache;

  var fromArgs = require( 'browserify/bin/args' );

  var b = argv ? fromArgs( argv, browserifyOpts ) : require( 'browserify' )( browserifyOpts );

  function normalizeCache( removeDeletedOnly ) {
    var cachedFiles = Object.keys( browserifyOpts.cache );

    var neverCache = opts.neverCache;
    if ( neverCache ) {
      if ( !Array.isArray( neverCache ) ) {
        neverCache = [ neverCache ];
      }
      cachedFiles.forEach( function ( file ) {
        for (var i = 0; i < neverCache.length; i++) {
          var regex = parseAsRegex( neverCache[ i ] );

          if ( file.match( regex ) ) {
            b.emit( 'skip:cache', file );
            delete browserifyOpts.cache[ file ]; //esfmt-ignore-line
            break;
          }
        }
      } );
    }

    var res = depsCacheFile.analyzeFiles( cachedFiles );

    var changedFiles = res.changedFiles;
    var notFoundFiles = res.notFoundFiles;

    var changedOrNotFound = removeDeletedOnly ? notFoundFiles : changedFiles.concat( notFoundFiles );

    if ( changedOrNotFound.length > 0 ) {
      changedOrNotFound.forEach( function ( file ) {
        delete browserifyOpts.cache[ file ]; //esfmt-ignore-line
      } );
    }

    cache.setKey( 'persistifyArgs', { cache: browserifyOpts.cache, packageCache: browserifyOpts.packageCache } );
  }

  normalizeCache();

  function collect() {
    b.pipeline.get( 'deps' ).push( through.obj( function ( row, enc, next ) {
      var file = row.expose ? b._expose[ row.id ] : row.file;
      persistifyCache.cache[ file ] = {
        source: row.source,
        deps: xtend( { }, row.deps )
      };
      b.emit( 'file', file ); // attempt to make latest watchify to work with persistify
      this.push( row );
      next();
    } ) );
  }

  if ( opts.watch ) {
    b = watchify( b, { ignoreWatch: b.argv[ 'ignore-watch' ] || b.argv.iw } );
  }

  collect();
  b.on( 'reset', collect );

  var oldBundle = b.bundle;
  b.bundle = function () {
    var start = Date.now();
    var stream;
    try {
      stream = oldBundle.apply( b, arguments );
      stream.on( 'error', function ( err ) {
        console.error( err ); // eslint-disable-line
      } );
      stream.on( 'end', function () {
        setTimeout( function () {
          normalizeCache( true /* remove deleted only*/ );
          depsCacheFile.reconcile();
          cache.save();
        }, 0 );

        var end = Date.now() - start;
        b.emit( 'bundle:done', end );
      } );
    } catch (ex) {
      console.error( ex ); // eslint-disable-line
    }

    return stream;
  };

  return b;
};