Make a beautiful class-based gulpfiles with Typescript and Gulpclass

Allows to create a gulp files in classes, each method of which can be a gulp task.

Installation

1. Install module:

   npm install gulpclass --save-dev

2. Use typings to install all required definition dependencies.

   typings install

Usage

1. Create a gulpfile.ts and describe your tasks

   import {Gulpclass, Task, SequenceTask} from "gulpclass";
   import * as gulp from "gulp";
   import * as del from "del";
   
   @Gulpclass()
   export class Gulpfile {
   
       @Task() // return promise to indicate your task completion
       clean() {
           // del module returns promise for you automatically
           return del("./dist/**");
       }
       
       @Task() // or use provided callback instead
       clean(cb: Function) {
           return del("./dist/**", cb);
       }
   
       @Task()
       copyFiles() { // don't forget to return stream from your task function
           return gulp.src(["./README.md"])
               .pipe(gulp.dest("./dist"));
       }
   
       @Task("copy-source-files") // you can specify custom task name if you need
       copySourceFiles() {
           return gulp.src(["./src/**.js"])
               .pipe(gulp.dest("./dist/src"));
       }
   
       @SequenceTask() // this special annotation using "run-sequence" module to run returned tasks in sequence
       build() {
           return ["copyFiles", "copy-source-files"];
       }
   
       // list of dependencies could be specified as a second argument to trigger other tasks
       // the example below is equivalent to `gulp.task("default", ["build"]);`
       @Task("default", ["build"])
       defaultTask() {
           // using "defaultTask", because "default" is a reserved keyword in ES2015
       }
   
   }

2. How to run

   First option. Use ts-node

   Install ts-node, it supports running gulp tasks directly using gulp command

   Second option. If you don't want to use ts-node

   There is a caveat of using gulp and typescript together. The problem is that when you run your gulp commands in console, gulp cannot read your tasks from your typescript code - it can read only from gulpfile.js. But there is a simple workaround - you can create a gulpfile.js, compile and execute typescript on-the-fly.

   Create a gulpfile.js and put there this piece of code:

   eval(require("typescript").transpile(require("fs").readFileSync("./gulpfile.ts").toString()));

   This piece of code reads your gulpfile.ts contents, and asks typescript to transpile it on-the-fly and executes transpiled result as javascript.

   (you need to run npm install typescript --save-dev if you dont have typescript package installed)

   Please note that if you are NOT using outDir in typescript compile options, you may have problems if your gulpclass file is named gulpfile.ts typescript compiler will try to compile it to gulpfile.js, and will override code you added to gulpfile.js. Solution is simple - rename your gulpfile.ts. You can call it as you wish, for example you can call it gulpclass.ts.

   Alternative approaches

   Alternative approaches depend on which tsconfig configuration you use. These examples assume that you are using "outDir": "build" as a directory to where files are compiled:

   • create gulpfile.js and put there require("build/gulpfile")
   • or run gulp in cmd with extra parameters: gulp --gulpfile build/gulpfile.js --cwd .

   Benefits of this apporach is that you can use debug your gulp classes in IDEs.

FAQ

• How to load tasks from multiple files?

Edit your gulpfile.js and change it following way:

const files = [
    "./othertask.ts",
    "./gulpfile.ts"
];
files.forEach(function(file) { eval(require("typescript").transpile(require("fs").readFileSync(file).toString())) });

• How to use task dependencies?

Simple use second argument of the @Task decorator:

@Task("someTask", ["clean", "compile"])
someTask() {
    return doSomething();
}

• Why my task gulp.task("default", ["clean", "compile", "build"]) is not working?

I have such a task and its not working:

@Task("default")
default() {
    return ["clean", "compile", "build"];
}

Why? Because the array you are returning is what task is doing, not a task dependencies as you wish:

@Task("default", ["clean", "compile", "build"])
default() {
}

Samples

This project itself using gulpfile.ts. Take a look on it as an example.