graph-ecs/tests/query.test.js

import { before, beforeEach, describe, it } from 'node:test'
import { addComponent, addEntity, createWorld, defineComponent, resetWorld, Types } from 'bitecs'
import assert from './assert.js'
import { query } from '../src/query.js'

let engine = {}

const create = (world, ...components) => {
    const entity = addEntity(world)
    components.forEach(cmp => addComponent(world, cmp, entity))
    return entity
}

const relate = (world, from, type, ...b) => {
    return b.map(to => {
        const edge = addEntity(world)
        addComponent(world, type, edge)
        update(type, { from, to }, edge)
        return edge
    })
}

const update = (type, values, entity) => {
    Object.entries(values).forEach(([k, v]) => { type[k][entity] = v })
}

describe('query', () => {
    before(() => {
        const world = { default: createWorld() }
        const component = {
            Player: defineComponent(null, 10),
            NPC: defineComponent(null, 10),
            Health: defineComponent({ current: Types.ui8, max: Types.ui8 }),
            Knows: defineComponent({
                from: Types.eid,
                to: Types.eid
            }, 10)
        }

        engine = { world, component }
    })

    beforeEach(() => {
        Object.values(engine.world).forEach(world => resetWorld(world))
    })

    it('should query on single components', () => {
        const world = engine.world.default
        const { Player, NPC, Knows } = engine.component

        const player = create(world, Player) // 0
        const a = create(world, NPC) // 1
        const b = create(world, NPC) // 2
        const c = create(world, NPC) // 3

        relate(world, player, Knows, a, c) // 4, 5
        relate(world, a, Knows, player, b, c) // 6, 7, 8
        relate(world, b, Knows, a) // 9
        relate(world, c, Knows, player) // 10

        // tag components should return an empty object
        assert.deepEqual(
            query('MATCH (player:Player) RETURN player', engine).unwrap(),
            [{ player: {} }]
        )

        assert.deepEqual(
            query('MATCH (player:Player)-[e1:Knows]->(a:NPC) RETURN player, e1, a', engine).unwrap(),
            [
                { player: {}, e1: { from: 0, to: 1 }, a: {} },
                { player: {}, e1: { from: 0, to: 3 }, a: {} }
            ]
        )

        assert.deepEqual(
            query('MATCH (player:Player)-[e1:Knows]->(a:NPC)-[e2:Knows]->(b:NPC) RETURN player, e1, a, e2, b', engine).unwrap(),
            [
                { player: {}, e1: { from: 0, to: 1 }, a: {}, e2: { from: 1, to: 2 }, b: {} },
                { player: {}, e1: { from: 0, to: 1 }, a: {}, e2: { from: 1, to: 3 }, b: {} }
            ]
        )
    })

    it('should match multiple components', () => {
        const world = engine.world.default
        const { Player, Health } = engine.component
        const player = create(world, Player, Health)

        Health.max[player] = 50
        Health.current[player] = 25

        // an unspecified component should return an Entity
        assert.deepEqual(
            query('MATCH (e, h:Health) RETURN e, h.max', engine).unwrap(),
            [{ e: 11, h: { max: 50 } }]
        )

        assert.deepEqual(
            query('MATCH (e:Entity, h:Health) RETURN e, h.max', engine).unwrap(),
            [{ e: 11, h: { max: 50 } }]
        )
    })

    it('should support filtering', () => {
        const world = engine.world.default
        const { Player, Health } = engine.component
        const player = create(world, Player, Health) // 12
        const enemy = create(world, Health) // 13

        update(Health, { max: 50, current: 25 }, player)
        update(Health, { max: 50, current: 35 }, enemy)

        assert.deepEqual(
            query('MATCH (e, h:Health) WHERE h.current < 30 RETURN e, h.max', engine).unwrap(),
            [{ e: 12, h: { max: 50 } }]
        )

        assert.deepEqual(
            query('MATCH (e, h:Health) WHERE e = 13 AND h.max = 50 OR h.current < 25 RETURN e, h.max', engine).unwrap(),
            [{ e: 13, h: { max: 50 } }]
        )

        assert.deepEqual(
           query('MATCH (e, h:Health) WHERE h.max = 50 OR h.current > 45 RETURN e, h.max AS maxHealth', engine).unwrap(),
           [
               { e: 12, maxHealth: 50 },
               { e: 13, maxHealth: 50 }
           ]
        )
        assert.deepEqual(
           query('MATCH (e, :Player, h:Health) WHERE (h.max = 50 OR h.current > 45) AND e = 12 RETURN e, h.max AS maxHealth', engine).unwrap(),
           [
               { e: 12, maxHealth: 50 }
           ]
        )
    })
})