@tractor/plugin-loader

Plugin loader for tractor to provide additional UI testing capabilities.


API

$3

Loads all available tractor plugins for a project.

``typescript
import { loadConfig } from '@tractor/config-loader';
import { loadPlugins } from '@tractor/plugin-loader';

const config = loadConfig(process.cwd(), './path/to/tractor.conf.js');
const plugins = loadPlugins(config);
`

$3

Retrieves the current plugins for the running Tractor instance. loadPlugins() must be called befere calling getPlugins().

`typescript
import { getPlugins } from '@tractor/plugin-loader';

const plugins = getPlugins();
`

How it works

Whenever tractor is run, the loader looks through your installed node modules, and finds any that are called @tractor-plugin/whatever. Those plugins could provide new actions for tests, new testing styles, or entirely new bits of UI/Functionality for the @tractor/ui application, all depending on what the plugin exports.

Plugin

A tractor plugin is just a plain old node module, with a few specially named exports, and maybe some bundled UI code. If you want to see an example of a basic plugin, check out tractor-plugin-browser. A plugin looks something like this:

`typescript
import { Config } from 'protractor';

export type TractorPlugin = {
description: {
actions: Array
};

create (): T;
init (): Promise | void;
plugin (protractorConfig: Config): Config;
run (): Promise | void;
serve (): Promise | void;
upgrade (): Promise | void;
};
`

$3

The description of the plugin object. Check out the type signature in more details here.

$3

Defines how an instance of the plugin will be instantiated when Protractor runs. It should return a concrete implementation of each of the description.

$3

Initialise anything that the plugin needs before it runs. This may be things like creating directories or getting information about the current environment, before tractor starts running.

$3

Modify the portractorConfig` before Protractor runs. This is where the plugin should set up any Protractor plugins that it needs. To see an example of how this works, check out @tractor-plugin/mocha-specs.

$3

Run any extra code the need before the app server starts. At the point that this is called all other plugins have been initialised and served.

$3

Define any new endpoints that the plugin needs to attach to the @tractor/server, typically for consuming from the @tractor/ui.

$3

A plugin can also contain UI code. The loader looks for a file at @tractor-plugin/my-plugin/dist/client/bundle.js and injects that into the @tractor/ui when it is served. It is run before the bootstrapping of the Angular application, so it can set-up routes etc. To see an example of how this works, check out @tractor-plugin/visual-regression.