flecs-zig-ble/test/world.zig

// Reimplementations of the following tests from Flecs:
// https://github.com/SanderMertens/flecs/blob/master/test/api/src/World.c

const std = @import("std");
const expect = std.testing.expect;
const expectEql = std.testing.expectEqual;
const expectStrEql = std.testing.expectEqualStrings;

const util = @import("./util.zig");

const flecs = @import("../src/main.zig");
const c = flecs.c;

const context = flecs.Context(void);
const World = context.World;
const Iter = context.Iter;
const Entity = context.Entity;

const Position = struct { x: f32, y: f32 };
const Velocity = struct { x: f32, y: f32 };

fn move(it: Iter) void {
    var pos = it.field(Position, 1);
    var vel = it.field(Velocity, 2);
    util.Probe.probeIter(it) catch unreachable;

    for (pos, vel) |*p, *v| {
        p.x += v.x * it.getDeltaTime();
        p.y += v.y * it.getDeltaTime();
    }
}

test "World_progress_w_0" {
    var world = try World.init(std.testing.allocator);
    defer world.deinit();

    _ = world.component(Position);
    _ = world.component(Velocity);

    const e1 = world.entity(&.{ Position, Velocity });

    const phase = Entity.fromRaw(world, c.EcsOnUpdate);
    const move_system = world.system("move", move, phase, "Position, Velocity");

    var ctx = util.Probe.init();
    c.ecs_set_context(world.raw, &ctx);

    e1.set(Position, .{ .x = 0, .y = 0 });
    e1.set(Velocity, .{ .x = 1, .y = 2 });

    _ = world.progress(0);

    try expectEql(ctx.count, 1);
    try expectEql(ctx.invoked, 1);
    try expectEql(ctx.system, move_system.raw);
    try expectEql(ctx.termCount, 2);
    try expectEql(ctx.param, null);

    try expectEql(ctx.e[0], e1.raw);
    try expectEql(ctx.c[0][0], world.lookup(Position).?.raw);
    try expectEql(ctx.c[0][1], world.lookup(Velocity).?.raw);
    try expectEql(ctx.s[0][0], 0);
    try expectEql(ctx.s[0][1], 0);

    const p = e1.get(Position).?;
    try expect(p.x != 0);
    try expect(p.y != 0);
}