gulp.js -如何将多个流返回到主流

Question

我想启动一个gulp.src流，将其管道到一个创建一堆新流的函数，然后将这些流的结果管道到gulp.dest。下面是我到目前为止，但它显然不工作，因为我管道流回gulp.dest爆炸，因为它期待一个文件，而不是一个流。所以我的问题是:我如何正确地将n数流返回到gulp的原始流，以便它们可以适当地继续沿着管道?

//gulpfile.js
var gulp = require('gulp'),
  bundle = require('./lib/bundle.js');
gulp.task('bundle', function() {
  return gulp.src('./bundle.config.js')
    .pipe(bundle())
    .pipe(gulp.dest('./public'));
});

//bundle.config.js
module.exports = {
  bundle: {
    main: {
      js: [
        './content/js/foo.js',
        './content/js/baz.js'
      ],
      css: [
        './content/**/*.css'
      ],
      resources: './content/**/*.{png,svg}'
    },
    other: {
      js: './content/js/other.js',
      css: '',
      resources: ''
    }
  }
};

//bundle.js
var gulp = require('gulp'),
  through = require('through2'),
  concat = require('gulp-concat');
module.exports = function () {
  return through.obj(function (file, enc, cb) {
    var config;
    try {
      config = require(file.path); // get config file
    } catch (e) {
      this.emit('error', e);
      return cb();
    }
    var streams = [];
    for (var key in config.bundle) {
      var bundle = config.bundle[key];
      streams.push(
        gulp.src(bundle.js, {base: '.'})
          .pipe(concat(key + '.js'))
      );
      streams.push(
        gulp.src(bundle.css, {base: '.'})
          .pipe(concat(key + '.css'))
      );
      streams.push(
        gulp.src(bundle.resources, {base: '.'})
        //.pipe(something())
      );
    }
    for (var i = 0; i < streams.length; i++) {
      // This causes an error in `gulp.dest` because we're returning the stream, not the file.
      // Instead, how do I resolve each of the individual streams and push the results back to the main stream??
      this.push(streams[i]);
    }
    cb();
  });
};

你可以看到这个示例代码，你可以在这个repo: https://github.com/chmontgomery/gulp-streams-to-stream

Answer 1

您可以使用merge-stream来连接流

var gulp = require('gulp');
var merge = require('merge-stream');
gulp.task('bundle', function () {
  var paths = [
    { src: 'src/admin/**', dest: './build/admin' },
    { src: 'src/public/**', dest: './build' }
  ];
  var tasks = paths.map(function (path) {
    return gulp.src(path.src).pipe(gulp.dest(path.dest));
  }
  return merge(tasks);
};

Answer 2

等待gulp.dest直到合并完流。

var gulp = require('gulp');
var es = require('event-stream');
var concat = require('gulp-concat');
gulp.task('bundle', function(cb) {
      //Sorry, forgot the bundling
      var paths = [{
        path: 'src/admin/**',
        filename: 'one.file'
      }, {
        path: 'src/public/**',
        filename: 'two.file'
      }];
      var tasks = paths.map(function(path) {
          return gulp.src(path.path)
          .pipe(concat(path.filename));
        }
        es.merge.apply(null, tasks)
        .pipe(gulp.dest('./dist/dest'))
        .on('end', cb);
      });