Merge pull request #141 from pmndrs/feat/constraint-schemas

feat: constrain trait schemas to no longer accept object or array literals

Author: krispya

packages/core/src/trait/trait.ts

@@ -14,13 +14,16 @@ import {
 	createSetFunction,
 } from './utils/create-accessors';
 import { createStore } from './utils/create-store';
+import { validateSchema } from './utils/validate-schema';
 
 let traitId = 0;
 
 function defineTrait<S extends Schema>(schema: S = {} as S): Trait<Norm<S>> {
 	const isAoS = typeof schema === 'function';
 	const traitType: TraitType = isAoS ? 'aos' : 'soa';
 
+	validateSchema(schema);
+
 	const Trait = Object.assign((params: Partial<Norm<S>>) => [Trait, params], {
 		schema: schema as Norm<S>,
 		[$internal]: {

packages/core/src/trait/utils/validate-schema.ts

@@ -0,0 +1,11 @@
+import { Schema } from '../types';
+
+export function validateSchema(schema: Schema) {
+	for (const key in schema) {
+		const value = schema[key as keyof Schema];
+		if (value !== null && typeof value === 'object') {
+			const kind = Array.isArray(value) ? 'array' : 'object';
+			throw new Error(`Koota: ${key} is an ${kind}, which is not supported in traits.`);
+		}
+	}
+}

packages/core/tests/trait.test.ts

@@ -29,6 +29,13 @@ describe('Trait', () => {
 		expect(typeof Test === 'function').toBe(true);
 	});
 
+	it('should throw an error if the schema contains an object or array', () => {
+		// @ts-expect-error - we want to test the error case
+		expect(() => trait({ object: { a: 1, b: 2 } })).toThrow();
+		// @ts-expect-error - we want to test the error case
+		expect(() => trait({ array: [1, 2, 3] })).toThrow();
+	});
+
 	it('should add and remove traits to an entity', () => {
 		const entity = world.spawn();