Custom webpack configuration - NativeScript Docs

What is webpack configuration

The webpack configuration file webpack.config.js is the file that contains all the configuration, plugins, loaders, etc. to build the JavaScript part of the NativeScript application. The file is located at the root of the NativeScript application. For each flavor (Angular, Vue.js, React, TypeScript, JavaScript) the content of the file is different as the way to process the files in the application differs. Currently the content is under user's control, but the default configuration file comes from nativescript-dev-webpack plugin during its postinstall step (or when you run the update-ns-webpack --configs script located in your <project dir>/node_modules/.bin/ directory). We are constantly trying to improve the content of the default webpack.config.js files, so during update of the nativescript-dev-webpack, we've added a check to see if the content of your application's webpack.config.js file differs from the new default one and show warning in such case. However, in many cases you need to add some custom logic in your webpack.config.js file, for example in case you have some assets that you need to copy or you have a custom Android activity. In this case, whenever you update nativescript-dev-webpack you will see the mentioned warning. Also, in case you want to be sure you've got all of the required changes from the default webpack.config.js coming with the new version of nativescript-dev-webpack, you have to merge the two webpack configurations manually.

How to use custom webpack configuration

From NativeScript v6.4.0 and nativescript-dev-webpack v1.5.0 you can use a custom path to webpack configuration. To achieve this you need to set webpackConfigPath property in your nsconfig.json file:

Set in nsconfig.json

{
    "webpackConfigPath": "./my-custom.webpack.config.js"
}

Create the actual file my-custom.webpack.config.js at the root of the application (as we've pointed in nsconfig.json that it is located there). In this file you can place your custom logic.

Example

const webpackConfig = require("./webpack.config");
module.exports = (env) => {
    // Here you can modify env before passing them to the default config
    const config = webpackConfig(env);

    // Here you can modify everything created by the default configuration
    return config;
}

NOTE: You may not require and use the default webpack.config.js file, but we strongly recommend you to do so. It contains the default rules and logic for processing your application scripts to NativeScript application.

Run the build/run operation to verify everything works as expected:

$ tns run <platform>

[Optional] Remove the webpack.config.js from your application and add it to .gitignore - in case you do not want to see the warnings for different webpack configurations anymore, you can safely remove the webpack.config.js and add it to your .gitignore file, so noone will commit it. This way, during dependency installation, the postinstall script of nativescript-dev-webpack will always place the current default configuration file. In case you prefer to check all the changes when you update the webpack.config.js file, you can still commit it in your repository with the default content and skip this step.

Examples

Here are a few example that demonstrate how you can use custom webpack configuration files

Add new assets to be copied

In case you want to copy additional assets to your application, you can use the following approach:

const webpackConfig = require("./webpack.config");
const CopyWebpackPlugin = require("copy-webpack-plugin");

module.exports = env => {
    const config = webpackConfig(env);
    const customCopyInstance = new CopyWebpackPlugin([
        { from: { glob: "my-custom-dir/**" } },
    ]);

    config.plugins.unshift(customCopyInstance);

    return config;
};

In this case we add a new instance of the CopyWebpackPlugin that will copy all files from our my-custom-dir directory to the build folder.

Custom application and activity (Android)

In case you have a custom application and activity for Android, you can do the following:

const webpackConfig = require("./webpack.config");
const path = require("path");

module.exports = env => {
    env = env || {};
    env.appComponents = env.appComponents || [];
    env.appComponents.push(path.resolve(__dirname, "app", "activity.android.ts"));

    env.entries = env.entries || {};
    env.entries.application = "./application.android";
    const config = webpackConfig(env);
    return config;
};

NOTE: In this example, our activity code is in the app directory, in activity.android.ts file. The application is located in app directory in application.android.ts file. A full example can be found here

Add additional rules for specific files

In case you want to have additional processing of some files:

const webpackConfig = require("./webpack.config");
const path = require("path");

module.exports = env => {

    const config = webpackConfig(env);

    const babelOptions = {
        babelrc: false,
        presets: [
            "@babel/preset-react"
        ],
        plugins: [ ]
    };

    config.module.rules.push(
        {
            test: /\.js(x?)$/,
            exclude: /node_modules/,
            use: {
                loader: "babel-loader",
                options: babelOptions
            },
        }
    );

    config.resolve.extensions = [".js", ".jsx", ".scss", ".css"];

    return config;
};

Remove default plugin

In some cases, you may want to remove some of the default plugins added by the default configuration:

const webpackConfig = require("./webpack.config");
const path = require("path");

module.exports = env => {
    env = env || {};
    const config = webpackConfig(env);
    if (env.ios) {
        config.plugins = config.plugins.filter(p => !(p && p.constructor && p.constructor.name === "HotModuleReplacementPlugin"));
    }

    return config;
};

In this example we demonstrate how you can remove the HotModuleReplacementPlugin plugin when building for iOS.

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