[Feature Request] Use virtual file as entry point

Do you want to request a feature or report a bug?

feature

What is the current behavior?

You must specify the entry point file path and output dir.

If the current behavior is a bug, please provide the steps to reproduce.

not a bugs.

What is the expected behavior?

We can specify the code string as an entry point.

If this is a feature request, what is motivation or use case for changing the behavior?

I some case. I build a builder cli base on webpack. I need to pack my code.

In current behavior, I gonna create a temp file and use it as entry file, so webpack can work it well.

webpack({
  entry: "/path/to/temp/file.js" // before pack the code, I need to create this temp file first
});

What if I can use code string as an entry point?

such as this:

webpack({
  entry: {
    code: "const xx = require('xxx'); // do something else",
    filepath: "/home/xxx/xxx.js"
  }
});

Or maybe we can make it better

const virtualEntryFile = new webpack.VirtualFile(
  "filepath.js",
  "// here is the js code string"
);

const virtualImages = new webpack.VirtualFile(
  "example.png",
  new Buffer()
);

webpack({
  entry: virtualEntryFile
});

In here, you can see that, I don’t need to create an intermediary file anymore

Please mention other relevant information such as the browser version, Node.js version, webpack version and Operating System.

[micha149]

I just tested virtual-module-webpack-plugin which seems to work with entry points and also (interesting for my case) as template source for the HtmlWebpackPlugin.

Example: const VirtualModulePlugin = require(‘virtual-module-webpack-plugin’);

{
    // ...
    entry: '/path/to/temp/file.js',
    // ...
    plugins: [
        new VirtualModulePlugin({
            moduleName: '/path/to/temp/file.js',
            contents: 'const xx = require('xxx'); // do something else',
        }),
    ],
}

[AlbertMarashi]

If you want to be able to access node_modules, I’d suggest using a memory file system + node fs and merging them with unionfs and then in the compiler using:

const {Union} = require('unionfs');
const MFS = require('memory-fs');
const fs = require('fs');
let mfs = new MFS();
let ufs = new Union();
ufs.use(mfs).use(fs);

const compiler = webpack(config);
compiler.inputFileSystem = this.ufs
compiler.outputFileSystem = this.mfs;