Huge News!Announcing our $40M Series B led by Abstract Ventures.Learn More
Socket
Sign inDemoInstall
Socket

@travetto/transformer

Package Overview
Dependencies
Maintainers
1
Versions
146
Alerts
File Explorer

Advanced tools

Socket logo

Install Socket

Detect and block malicious and high-risk dependencies

Install

@travetto/transformer

Functionality for AST transformations, with transformer registration, and general utils

  • 3.4.3
  • Source
  • npm
  • Socket score

Version published
Weekly downloads
31
increased by181.82%
Maintainers
1
Weekly downloads
 
Created
Source

Transformation

Functionality for AST transformations, with transformer registration, and general utils

Install: @travetto/transformer

npm install @travetto/transformer

# or

yarn add @travetto/transformer

This module provides support for enhanced AST transformations, and declarative transformer registration, with common patterns to support all the transformers used throughout the framework. Transformations are located by support/transformer.<name>.ts as the filename.

The module is primarily aimed at extremely advanced usages for things that cannot be detected at runtime. The Registry module already has knowledge of all classes and fields, and is able to listen to changes there. Many of the modules build upon work by some of the foundational transformers defined in Manifest, Registry, Schema and Dependency Injection. These all center around defining a registry of classes, and associated type information.

Because working with the Typescript API can be delicate (and open to breaking changes), creating new transformers should be done cautiously.

Monorepos and Idempotency

Within the framework, any build or compile step will target the entire workspace, and for mono-repo projects, will include all modules. The optimization this provides is great, but comes with a strict requirement that all compilation processes need to be idempotent. This means that compiling a module directly, versus as a dependency should always produce the same output. This produces a requirement that all transformers are opt-in by the source code, and which transformers are needed in a file should be code-evident. This also means that no transformers are optional, as that could produce different output depending on the dependency graph for a given module.

Custom Transformer

Below is an example of a transformer that upper cases all class, method and param declarations. This will break any code that depends upon it as we are redefining all the identifiers at compile time.

Code: Sample Transformer - Upper case all declarations

import ts from 'typescript';

import { OnProperty, TransformerState, OnMethod, OnClass } from '@travetto/transformer';

export class MakeUpper {

  @OnProperty()
  static handleProperty(state: TransformerState, node: ts.PropertyDeclaration): ts.PropertyDeclaration {
    if (!state.importName.startsWith('@travetto/transformer/doc/upper')) {
      return node;
    }
    return state.factory.updatePropertyDeclaration(
      node,
      node.modifiers,
      node.name.getText().toUpperCase(),
      undefined,
      node.type,
      node.initializer ?? state.createIdentifier('undefined')
    );
  }

  @OnClass()
  static handleClass(state: TransformerState, node: ts.ClassDeclaration): ts.ClassDeclaration {
    if (!state.importName.startsWith('@travetto/transformer/doc/upper')) {
      return node;
    }
    return state.factory.updateClassDeclaration(
      node,
      node.modifiers,
      state.createIdentifier(node.name!.getText().toUpperCase()),
      node.typeParameters,
      node.heritageClauses,
      node.members
    );
  }

  @OnMethod()
  static handleMethod(state: TransformerState, node: ts.MethodDeclaration): ts.MethodDeclaration {
    if (!state.importName.startsWith('@travetto/transformer/doc/upper')) {
      return node;
    }
    return state.factory.updateMethodDeclaration(
      node,
      node.modifiers,
      undefined,
      state.createIdentifier(node.name.getText().toUpperCase()),
      undefined,
      node.typeParameters,
      node.parameters,
      node.type,
      node.body
    );
  }
}

Note: This should be a strong indicator that it is very easy to break code in unexpected ways.

Code: Sample Input

export class Test {
  name: string;
  age: number;
  dob: Date;

  computeAge(): void {
    this['age'] = (Date.now() - this.dob.getTime());
  }
}

Code: Sample Output

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.TEST = void 0;
const tslib_1 = require("tslib");
const Ⲑ_root_index_1 = tslib_1.__importStar(require("@travetto/manifest/src/root-index.js"));
const Ⲑ_decorator_1 = tslib_1.__importStar(require("@travetto/registry/src/decorator.js"));
var ᚕf = "@travetto/transformer/doc/upper.js";
let TEST = class TEST {
    static Ⲑinit = Ⲑ_root_index_1.RootIndex.registerFunction(TEST, ᚕf, 649563175, { COMPUTEAGE: { hash: 1286718349 } }, false, false);
    NAME;
    AGE;
    DOB;
    COMPUTEAGE() {
        this['AGE'] = (Date.now() - this.DOB.getTime());
    }
};
exports.TEST = TEST;
exports.TEST = TEST = tslib_1.__decorate([
    Ⲑ_decorator_1.Register()
], TEST);

Keywords

FAQs

Package last updated on 18 Jan 2024

Did you know?

Socket

Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.

Install

Related posts

SocketSocket SOC 2 Logo

Product

  • Package Alerts
  • Integrations
  • Docs
  • Pricing
  • FAQ
  • Roadmap
  • Changelog

Packages

npm

Stay in touch

Get open source security insights delivered straight into your inbox.


  • Terms
  • Privacy
  • Security

Made with ⚡️ by Socket Inc