Overview

Mutates is a fork of ng-morph that is focused on mutating the AST of Angular components.

The biggest difference is that this fork is not focused on Angular specific transformations. Mutates is a set of tools that can be used to mutate the AST of any TypeScript file.

All framework-specific transformations have been moved to separate packages (e.g. @mutates/angular).

The main package is @mutates/core which provides the core functionality for mutating the AST of TypeScript files.

First steps

To get started, you can install the core package:

npm install @mutates/core -D

Then, you can use the core functionality to mutate the AST of any TypeScript file.

import { addSourceFiles, createProject, getClasses } from '@mutates/core';

createProject();

addSourceFiles(['src/**/*.ts']);

const componentCount = getClasses('**/*.ts').length;

console.log(`Found ${componentCount} components.`);

createProject by default create project which works with real file system. If you want to change this behavior you can pass FileSystemHost implementation to createProject function. For example you can use InMemoryFileSystemHost from ts-morph package. Inside project we use it to test our transformations.

import { InMemoryFileSystemHost } from 'ts-morph';

import { createProject, createSourceFile, getClasses } from '@mutates/core';

createProject(new InMemoryFileSystemHost());

createSourceFile('src/index.ts', 'export class Test {}');

const componentCount = getClasses('**/*.ts').length;

console.log(`Found ${componentCount} components.`);

To support Angular schematics and migrations we have @mutates/angular package. It provides createAngularProject function which creates project with Angular specific configuration.

import { createAngularProject, getComponents } from '@mutates/angular';
import { Tree } from '@angular-devkit/schematics';

export function ngAdd(options: scssScaffoldOptions): Rule {
  return (host: Tree) => {
    createAngularProject(host);

    const components = getComponents('**/*.ts');

    console.log(`Found ${components.length} components.`);

    return host;
  }
}