@sewing-kit/hooks

@sewing-kit/hooks

Interfaces and types for sewing-kit hooks.

Installation

yarn add @sewing-kit/hooks --dev

Overview

Hooks, along with plugins, form the functional heart of sewing-kit. Inspired by webpack's tapable library (guide), hooks provide a way for plugins to tap into sewing-kit tasks in order to impart functionality to your workspace's dev setup.

Calling hooks

The two types of hooks provided are a SeriesHook and a WaterfallHook. Both of these clases provide a hook and run method

import {SeriesHook} from '@sewing-kit/hooks';

const dog = {
  breed: new SeriesHook<string>(),
};

dog.breed.hook((breed) => {
  console.log('Received changes on the breed: ', breed);
});

dog.breed.run('American Bully');
// Received changes on the breed: American Bully

SeriesHook vs WaterfallHooks

When run is called on a SeriesHook all the conainted hooks are resolved in sequential order. With a Waterfall hook, the result of a hook is passed in as the argument for the next hook.

Usage

Adding hooks

A lot of your use cases can probably covered by the hooks provided by core sewing-kit, but you can always add your own hooks via plugins and a task's configureHooks hook (adding hooks with hooks). For example, if you add, say, a plugin that introduces Jest to your workspace's testing setup, that plugin can also add a hook to let other plugins hook into its Jest configuration.

// Code from @sewing-kit/plugin-jest

hooks.configureHooks.hook(
  addHooks<JestWorkspaceHooks>(() => ({
    jestSetupEnv: new WaterfallHook(),
    jestSetupTests: new WaterfallHook(),
    jestWatchPlugins: new WaterfallHook(),
    jestConfig: new WaterfallHook(),
    jestFlags: new WaterfallHook(),
  })),
);

Configuring/tapping into hooks

Following from the previous example, another plugin further down might then do something like:

createWorkspaceTestPlugin('CustomPlugin', ({hooks}) => {
  hooks.configure.hook((hooks) => {
    hooks.jestSetupEnv.hook((oldJestSetupEnv) => {
      // Do something to oldJestSetupEnv and return the new value
    });

    hooks.jestConfig.hook((oldJestConfig) => {
      // Do something to oldJestConfig and return the new value
    });

    // ..etc
  });
});

When you run sk test, sewing-kit will pick up your configs and plugins and run Jest with your specified option/config values.