ng-custom-transformers

Because Angular CLI does not support custom TypeScript transformers/plugins (there is still an open feature request, more than 4 years), custom transformers must be configured manually by tampering with the Webpack configuration file.

Compatibility

This package has one peer dependency which is "@ngtools/webpack": ">=12.0.0". Which is generally Angular 12 and higher.

Disclaimer

Since custom TypeScript transformers/plugins are not officially supported by the Angular CLI, this package rely on unexported private features. Currently, it works like a charm, without changing the default behavior, but it may be broken by the future Angular updates so there can be no guarantee.

Usage

1. Install this package.
   npm i ng-custom-transformers -D
2. Add your transformer into the tsconfig.json. Format is the same like one defined by ttypescript, but don't use ttypescript, Angular has own pipeline for transformers.

{
    "compilerOptions": {
        // ... your options ...

        // ADD THIS SECTION!
        "plugins": [
            {
                "transform": "tst-reflect-transformer"
            },
            // use transformer you want
        ]
    }
}

Currently, only transform property is supported, which is a transformer package name or path to a transformer. Other options defined by ttypescript are not implemented yet. Feel free to create PR!

3. let function exported from this package modify Webpack config used by Angular. This can be done by ngx-build-plus or by @angular-builders/custom-webpack, which are packages that allows you to modify Angular's Webpack config. choose one and continue in corresponding section.

@angular-builders/custom-webpack

1. npm i @angular-builders/custom-webpack -D
2. Create file mod.webpack.config.js.

const {AngularCustomTransformers} = require("ng-custom-transformers");

module.exports = (config, options, targetOptions) => {
    // Your transformations of "config" ....

    // And the important part here: modifyConfig()
    return AngularCustomTransformers.modifyConfig(config);
};

or .ts

import { AngularCustomTransformers } from "ng-custom-transformers";
import {
    CustomWebpackBrowserSchema,
    TargetOptions
}                                    from "@angular-builders/custom-webpack";
import * as webpack                  from "webpack";

export default function (
    config: webpack.Configuration,
    options: CustomWebpackBrowserSchema,
    targetOptions: TargetOptions
)
{
    // Your transformations of "config"...

    // And the important part here: modifyConfig()
    return AngularCustomTransformers.modifyConfig(config);
}

3. Modify angular.json.

{
    "architect": {
        // ...
        "build": {
            "builder": "@angular-builders/custom-webpack:browser",
            // use @angular-builders/custom-webpack builder
            "options": {
                "customWebpackConfig": {
                    "path": "./mod.webpack.config.js"
                }
                // ...
            }
        }
    }
}

4. ng build or ng serve

ngx-build-plus

1. ng add ngx-build-plus
2. ng build --plugin ng-custom-transformers or ng serve --plugin ng-custom-transformers