pluginCustomtransform

Usage

The custom transform plugin enables you to arbitrarily change the way code is transformed using custom AST transformers. Custom transformers are a standard feature of the TypeScript Compiler API since version 2.3. A good writeup on how custom AST transformation works can be found here.

This plugin exposes the public API for providing custom transformers so that you can safely add your own transformers on top of the transformers used by fuse-box internally:

Examples

import * as ts from 'typescript';
import { fusebox, pluginJSON } from 'fuse-box';
fusebox({
  plugins: [
    pluginCustomTransform({
      before: [customTransformer('before')],
      after: [customTransformer('after')],
    }),
  ],
});

Each transformer must fulfill the TransformerFactory<T> interface:

import * as ts from 'typescript';

export function customTransformer<T extends ts.Node>(type: string): ts.TransformerFactory<T> {
  return (context) => {
    console.log(`\n===> do some custom ${type} AST node transformation here\n`);

    const visit: ts.Visitor = (node) => {
      return ts.visitEachChild(node, (child) => visit(child), context);
    };
    return (node) => ts.visitNode(node, visit);
  };
}