Modernise Service embedded + accept a generic type parameter

[MrChocolatine]

Documentation

Add a section about TypeScript support (#149)

Features

Allow to pass type of embedded options to Service embedded (#149)

The Service embedded now accepts a generic type parameter to improve the accuracy of what it can return.

import Component from '@glimmer/component';
import { inject as service } from '@ember/service';

import type EmbeddedService from 'ember-cli-embedded/services/embedded';

export default class MyComponent extends Component {
  @service
  declare embedded: EmbeddedService<{ one: string, two?: string }>;

  get one() { // Return type inferred: `string | undefined`
    return this.embedded.get('one');
  }

  get two() {
    // TypeScript returns an error as `twoo` is not a recognised key
    return this.embedded.get('twoo');
  }
}

Refactor

Update Service embedded to native JS class (#149)

Tests

Make tests of Service embedded stricter (#149)

Prefer assert.strictEqual() over assert.equal().