吞咽任务竞赛条件

Question

我有一个吞咽任务（a）同步的问题。以下是我的gulp文件。基本上，我想先清理目录，然后将一些文件复制/生成到新目录中。问题在于竞争状态。我需要执行clean和然后执行所有其余的（在build任务内）。

当前的执行或者按预期完成，或者由于竞争条件导致ENOENT目录不存在而失败。

var gulp = require('gulp'); 
var concat = require('gulp-concat'); 
var clean = require('gulp-clean'); 
var cleanCSS = require('gulp-clean-css'); 

var cfg = { 
    js: { 
    vendor: [ 
     './node_modules/angular/angular.min.js', 
     './node_modules/angular-translate/dist/angular-translate.min.js', 
     './node_modules/angular-bootstrap/ui-bootstrap.min.js', 
     './node_modules/angular-bootstrap/ui-bootstrap-tpls.min.js' 
    ], 
    app: './app/js/*' 
    }, 
    css: { 
    vendor: [ 
     './node_modules/bootstrap/dist/css/bootstrap.css', 
     './node_modules/font-awesome/css/font-awesome.css' 
    ], 
    app: './app/css/*' 
    } 
}; 

gulp.task('clean', function() { 
    return gulp.src('./dist', {read: false}) 
    .pipe(clean()); 
}); 

gulp.task('vendor-js', function() { 
    return gulp.src(cfg.js.vendor) 
    .pipe(concat('vendor.js')) 
    .pipe(gulp.dest('./dist/')); 
}); 

gulp.task('app-js', function() { 
    return gulp.src(cfg.js.app) 
    .pipe(concat('app.js')) 
    .pipe(gulp.dest('./dist/')); 
}); 

gulp.task('vendor-css', function() { 
    return gulp.src(cfg.css.vendor) 
    .pipe(cleanCSS({compatibility: 'ie8'})) 
    .pipe(concat('vendor.css')) 
    .pipe(gulp.dest('./dist/')); 
}); 

gulp.task('app-css', function() { 
    return gulp.src(cfg.css.app) 
    .pipe(cleanCSS({compatibility: 'ie8'})) 
    .pipe(concat('app.css')) 
    .pipe(gulp.dest('./dist/')); 
}); 

gulp.task('fonts', function() { 
    gulp.src('./app/fonts/**/*') 
    .pipe(gulp.dest('./dist/fonts')); 

    gulp.src('./node_modules/font-awesome/fonts/**/*') 
    .pipe(gulp.dest('./dist/fonts')); 
}); 

gulp.task('build', [ 
    'clean', 
    'vendor-js', 
    'app-js', 
    'vendor-css', 
    'app-css', 
    'fonts' 
]); 

gulp.task('default', ['build']); 

Answer 1

实际上，对于串行（同步）任务一饮而尽支持是有点蹩脚，需要做的克服，因为它是不是应用的非标要求...

由于clean任务是已经做了一回，这项工作是：

• 定义任务依赖于clean对于需要它
• 后各单项任务，从去除

最终的解决方案是：

var gulp = require('gulp'); 
var concat = require('gulp-concat'); 
var clean = require('gulp-clean'); 
var uglify = require('gulp-uglify'); 
var cleanCSS = require('gulp-clean-css'); 

var cfg = { 
    js: { 
    vendor: [ 
     './node_modules/angular/angular.min.js', 
     './node_modules/angular-translate/dist/angular-translate.min.js', 
     './node_modules/angular-bootstrap/ui-bootstrap.min.js', 
     './node_modules/angular-bootstrap/ui-bootstrap-tpls.min.js' 
    ], 
    app: './app/js/*' 
    }, 
    css: { 
    vendor: [ 
     './node_modules/bootstrap/dist/css/bootstrap.css', 
     './node_modules/font-awesome/css/font-awesome.css' 
    ], 
    app: './app/css/*' 
    }, 
    fonts: [ 
    './app/fonts/**/*', 
    './node_modules/font-awesome/fonts/**/*', 
    './node_modules/bootstrap/fonts/**/*' 
    ] 
}; 

gulp.task('clean', function() { 
    return gulp.src('./dist', {read: false}) 
    .pipe(clean()); 
}); 

gulp.task('vendor-js', ['clean'], function() { 
    return gulp.src(cfg.js.vendor) 
    .pipe(concat('vendor.js')) 
    .pipe(gulp.dest('./dist/'));}); 

gulp.task('app-js', ['clean'], function() { 
    return gulp.src(cfg.js.app) 
    .pipe(uglify('app.js')) 
    .pipe(gulp.dest('./dist/')); 
}); 

gulp.task('vendor-css', ['clean'], function() { 
    return gulp.src(cfg.css.vendor) 
    .pipe(cleanCSS({compatibility: 'ie8'})) 
    .pipe(concat('vendor.css')) 
    .pipe(gulp.dest('./dist/')); 
}); 

gulp.task('app-css', ['clean'], function() { 
    return gulp.src(cfg.css.app) 
    .pipe(cleanCSS({compatibility: 'ie8'})) 
    .pipe(concat('app.css')) 
    .pipe(gulp.dest('./dist/')); 
}); 

gulp.task('fonts', function() { 
    gulp.src(cfg.fonts) 
    .pipe(gulp.dest('./fonts')); 
}); 

gulp.task('build', [ 
    'vendor-js', 
    'app-js', 
    'vendor-css', 
    'app-css', 
    'fonts' 
]); 

gulp.task('default', ['build']);