Test Area and Time

TestArea

The game leaves only a few blocks between test areas. If a test places blocks beyond one block or moves mobs, reserve space with TestArea. Otherwise it overlaps with neighboring tests and fails now and then.

mod.gameTests().register("ore_vein", 100, TestArea.cube(9), test -> {
    test.runCommand("fill ~1 ~1 ~1 ~7 ~7 ~7 minecraft:stone");
    test.assertTrue(test.runCommand("place feature ruby_mod:ruby_ore ~4 ~4 ~4") == 1, "place the ore");
    test.succeed();
});

• TestArea.cube(size) is a cube, and new TestArea(width, height, depth) is a cuboid.
• If you do not set one, it is TestArea.SINGLE_BLOCK (1×1×1).
• Poly Mod Loader writes an empty structure of that size into the generation pack.

Tests that take time

Raise the maximum number of ticks, and check later with runAfter.

mod.gameTests().register("machine_finishes", 80, test -> {
    // …place the machine and insert the ingredients…
    test.runAfter(45, () -> {
        test.assertTrue(output.count() == 1, "1 output after 40 ticks");
        test.succeed();
    });
});

Wait until a condition is true

When you do not know the exact tick count, check again at short intervals. If the condition does not become true in time, the test fails with a timeout.

/** Checks condition every 5 ticks and runs then once it is true. */
static void poll(GameTestContext test, BooleanSupplier condition, Runnable then) {
    test.runAfter(5, () -> {
        if (condition.getAsBoolean()) {
            then.run();
        } else {
            poll(test, condition, then);
        }
    });
}

Test a scheduled task

mod.gameTests().register("scheduled_task_runs", 20, test -> {
    AtomicInteger runs = new AtomicInteger();
    test.world().schedule(3, runs::incrementAndGet);
    test.runAfter(1, () -> test.assertTrue(runs.get() == 0, "task did not run early"));
    test.runAfter(6, () -> {
        test.assertTrue(runs.get() == 1, "task ran once, ran " + runs.get());
        test.succeed();
    });
});

Game test server limits

The game test server creates dimensions only from the flat preset, so there are no data dimensions. Check mod dimensions in a normal world.