Diderot

Dependency Injection, your way

Highlights

Predictable

Diderot is strictly-typed. Registering a function returns a typed Token. Getting a token returns a typed value. Replacing a token can only be done if the replacement and the replaced tokens are compatibles - i.e. if their return types are identical. With Diderot, you can't make any mistake at compile-time: you always know what you register, what you get and what you replace.

Reliable

Diderot does not depend on experimental features, like Decorators or Metadata Reflection, that are subjects to breaking changes in the future.

Flexible

Diderot makes no assumption on nor enforces you to a methodology. Use it your own way. Be creative. Don't stick to the consensus. Freedom of thinking is the way to enlightenment.

Installation

npm i diderot

Usage

import {Container} from "diderot";
import {deepStrictEqual} from "assert";

const container = new Container();

// register a function and get a token
const name = container.register(() => 'SpongeBob SquarePants', []);

// get a value from a token
deepStrictEqual(container.get(name), 'SpongeBob SquarePants');

// replace a token by another token
container.replace(name, () => 'Patrick Star');

deepStrictEqual(container.get(name), 'Patrick Star');

// compose with tokens
const bestFriends = container.register((
    person: string, 
    bestie: string
) => `${person} and ${bestie} are besties`, [name, name]);

deepStrictEqual(container.get(bestFriends), 'Patrick Star and Patrick Star are besties');

// compose with functions
container.replace(bestFriends, container.register((
    person: string, 
    bestie: string
) => `${person} and ${bestie} are besties`, [() => name(), () => 'Patrick Star']));

deepStrictEqual(container.get(bestFriends), 'SpongeBob SquarePants and Patrick Star are besties');

// compose with a mix of functions and tokens
container.replace(bestFriends, container.register((
    person: string, 
    bestie: string
) => `${person} and ${bestie} are besties`, [() => name(), name]));

deepStrictEqual(container.get(bestFriends), 'SpongeBob SquarePants and Patrick Star are besties');

// detect mistakes at compile-time
const number = container.register(() => 5, []); // () => number

container.replace(bestFriends, number); // TS2322: Type '() => number' is not assignable to type '() => string'.

API

Read the documentation for more information.

Contributing

• Fork the main repository
• Code
• Implement tests using tape
• Issue a pull request keeping in mind that all pull requests must reference an issue in the issue queue

License

Apache-2.0 © Eric MORAND