How to provide global TypeScript classes via WebPack bundle in JS

Question

I am currently working on TypeScript. I want to replace JS with TS, but I have a lot of JS-Files, so that I only want to create new classes in TS and want to use these in my old JS files atm. Later on I want to replace all JS with TS.

I not 100% familiar with webpack and bundled js files, so that I could use some help.

Is there any opportunity to compile TS into JS with gulp (already done - it works) AND use these TS classes in different (old) JS files?

TypeScript file:

class Car {
    seats: number;
    passengers: string[];

    add(passenger: string) {
        if(this.passengers.indexOf(passenger) === -1) {
            this.passengers.push(passenger);
        }
    }
}

JavaScript file:

var car = new Car();
car.seats = 5;
car.add("Pete");

As you can mention, Car is undefined.

How can I use my Car class in other JS files? (after ts compilation and webpack bundling)

This is my old gulp task:

gulp.task('bundle-ts-webpack', ['compile-ts-webpack'], function() {
    var tsFiles = glob.sync(config.js.tsSource);

    return webpackStream({
        /* configuration options */
        entry: tsFiles,
        module: {
            rules: [
                {
                    //test: /\.tsx?$/,
                    use: 'ts-loader',
                    exclude: /node_modules/
                }
            ]
        },
        resolve: {
            extensions: ['.tsx', '.ts', '.js'],
            // use ts in js - begin
            alias: {
                'TS': path.resolve(config.js.tsDest, 'ts-bundle'),
                'ExpertFilterHelper': path.resolve('./static/ts/', 'car'),
                'test': path.resolve('.static/ts/', 'test-globals')
            }
            // use ts in js - end
        },
        // use ts in js - begin
        plugins: [
            new webpack.ProvidePlugin({
                'TS': 'TS',
                identifier: 'car',
                test: 'test'
            })
        ],
        // use ts in js - end
        output: {
            filename: 'ts-bundle.js',
            path: path.resolve(config.js.tsDest, 'dist')
        }
    })
        .pipe(gulp.dest(config.js.tsDest));
});

I already tried to get this running as you can see in the gulp.task, but I still "dont know what I am doing here".

Can someone give me a hint?

I already thought, whether I should compile TS to JS first and then bundle it via webpack, but I dont know whether this solve my problem.

Edit/Updated:

As Joshua Barnett mentioned, you can use the expose-loader, but I still have a question to the expose-loader:

Can I only add one typescript file to the globals?

I have three typescript files for exmaple:

• A.ts
• B.ts
• Car.ts

This works fine: I can now use:

Library.Car()

BUT: When I have another typescript file/class like so:

• A.ts
• B.ts
• Car.ts
• Delivery.ts

I can only use Library.Delivery() and cannot use Library.Car() anymore. Any hints for that?

My current gulp.task:

gulp.task('compile-ts-webpack', function() {
    var tsFiles = glob.sync('./static/ts/*.ts');

    console.log(require.resolve('./static/ts/z-car-test.ts'));

    return webpackStream(
        {
            entry: tsFiles,//path.resolve('./static/ts/z-car-test.ts'),
            output: {
                filename: 'ts-bundle.js',
                path: path.resolve('./static/js/modules')
            },
            devtool: "source-map",
            resolve: {
                extensions: ['.tsx', '.ts', '.js']
            },
            module: {
                rules: [{
                    test: /\.ts|\.tsx$/, //require.resolve('./static/ts/z-car-test.ts'),
                    use: [{
                        loader: 'expose-loader',
                        options: 'TSGlobals'
                    }, {
                        loader: 'ts-loader'
                    }]
                    //exclude: /node_modules/
                }]
            }
        }
    ).pipe(gulp.dest('./static/js/modules'));

Edit/Update 2:

If you want to have more than one class added to the TSGlobals you can do that with a little hack (I guess it's a hack, im not sure)

I created a exporter.ts which re-exports all classes I need to be global to use these in any js-file as Joshua Barnett mentioned in a comment:

//exporter.ts
export { Car } from "./car.ts";
export { Delivery } from "./delivery.ts";

I also need to tell webpack to bundle the exporter typescript file at the end of the files-array. (Im not 100% sure why)

//gulp.task
gulp.task('compile-ts', ['clean-ts'], function() {
    var tsFiles = glob.sync('./ts/*.ts', {"ignore":['./exporter.ts']}); // Ignore exporter.ts

//add the exporter.ts to the end of the array to provide the global TSGlobals Library.
    tsFiles.push(config.js.tsExporterFile);
[...]
}

Now I can use TSGlobals in any JS-file! Works perfectly.

//whatever.js
var car = new TSGlobals.Car();
car.seats = 5;
car.add('Pete');

var delivery = new TSGlobals.Delivery();
delivery.doSomething("123");

Answer 1

You need to make use of the expose-loader in order to make your module available through the global scope.

---

// File: webpack.config.js
const path = require('path')

module.exports = {
  context: path.resolve('src'),
  entry: './main.ts',
  module: {
    rules: [
      {
        test: require.resolve('./src/main.ts'),
        use: [{
          loader: 'expose-loader',
          options: 'Library'
        }, {
          loader: 'ts-loader'
        }],
        exclude: /node_modules/
      }
    ]
  },
  output: {
    path: path.resolve(__dirname, 'dist'),
    filename: 'bundle.js'
  }
}

---

// File: main.ts
export class Car {
    seats: number;
    passengers: string[];

    add(passenger: string) {
        if(this.passengers.indexOf(passenger) === -1) {
            this.passengers.push(passenger);
        }
    }
}

---

// File: main.js
var car = new Library.Car()
car.seats = 5
car.add('Pete')

---

Make sure the code calling the module is included after the module bundle.

<!-- File: index.html -->
<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
    <title>Webpack App</title>
  </head>
  <body>
    <script type="text/javascript" src="bundle.js"></script>
    <script src="main.js"></script>
  </body>
</html>