node-data-modeling/test/registry.js

"use strict";

const expect = require("chai").expect;

const dm = require("../src");

describe("registry", () => {
	let registry = dm.createRegistry();

	describe("registry API", () => {
		it("should not expose registry-specific methods on the primary module API", () => {
			expect(dm.type).to.equal(undefined);
			expect(dm.trait).to.equal(undefined);
		});

		it("should expose the createRegistry method on the primary module API", () => {
			expect(dm.createRegistry).to.be.a("function");
		});

		it("should expose registry-specific methods on the registry API", () => {
			expect(registry.type).to.be.a("function");
			expect(registry.trait).to.be.a("function");
		});

		it("should not expose the createRegistry method on the registry API", () => {
			expect(registry.createRegistry).to.equal(undefined);
		});
	});

	describe("registry usage", () => {
		it("should work correctly for types", () => {
			let Person = registry.createType("Person", {
				name: dm.string(),
				favouriteGift: registry.type("Gift").optional()
			});

			let Gift = registry.createType("Gift", {
				description: dm.string(),
				from: registry.type("Person"),
				to: registry.type("Person")
			});

			let joe = Person({
				name: "Joe"
			});

			let jane = Person({
				name: "Jane"
			});

			let flowers = Gift({
				description: "Flowers",
				from: jane,
				to: joe
			});

			joe.favouriteGift = flowers;

			expect(joe.favouriteGift).to.equal(flowers);
			expect(flowers.to).to.equal(joe);
			expect(flowers.from).to.equal(jane);

			expect(() => {
				jane.favouriteGift = "not a gift";
			}).to.throw("Expected an instance of Gift, got a string instead");

			expect(() => {
				flowers.to = "not a person";
			}).to.throw("Expected an instance of Person, got a string instead");

			expect(() => {
				flowers.to = flowers;
			}).to.throw("Expected an instance of Person, got an instance of Gift instead");
		});

		it("should work correctly for traits", () => {
			let Givable = registry.createTrait("Givable", {
				from: registry.type("Person"),
				to: registry.type("Person")
			});

			let Person = registry.createType("Person", {
				name: dm.string(),
				favouriteGift: registry.trait("Givable").optional()
			});

			let Gift = registry.createType("Gift", {
				description: dm.string()
			}).implements(Givable, {
				from: dm.slot(),
				to: dm.slot()
			});

			let joe = Person({
				name: "Joe"
			});

			let jane = Person({
				name: "Jane"
			});

			let flowers = Gift({
				description: "Flowers",
				from: jane,
				to: joe
			});

			joe.favouriteGift = flowers;

			expect(joe.favouriteGift).to.equal(flowers);
			expect(flowers.to).to.equal(joe);
			expect(flowers.from).to.equal(jane);

			expect(() => {
				jane.favouriteGift = "not a gift";
			}).to.throw("Expected object of a type with the Givable trait, got a string instead");

			expect(() => {
				flowers.to = "not a person";
			}).to.throw("Expected an instance of Person, got a string instead");

			expect(() => {
				flowers.to = flowers;
			}).to.throw("Expected an instance of Person, got an instance of Gift instead");
		});
	});
});