core/src/test/java/coffee/liz/lambda/eval/ThunkTest.java


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package coffee.liz.lambda.eval;

import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;
import org.mockito.Mockito;

import java.util.concurrent.atomic.AtomicInteger;
import java.util.function.Supplier;

public class ThunkTest {
    @Test
    public void testThunkNonNull() {
        final AtomicInteger invok = new AtomicInteger(0);
        final Supplier<Integer> i = () -> {
            invok.incrementAndGet();
            return invok.get();
        };
        final Thunk<Integer> thunk = new Thunk<>(i);
        Assertions.assertEquals(1, thunk.get());
        Assertions.assertEquals(1, thunk.get());
        Assertions.assertEquals(1, thunk.get());
        Assertions.assertEquals(1, invok.get());
    }

    @Test
    public void testThunkNull() {
        final AtomicInteger invok = new AtomicInteger(0);
        final Supplier<Integer> i = () -> {
            invok.incrementAndGet();
            return null;
        };
        final Thunk<Integer> thunk = new Thunk<>(i);
        Assertions.assertNull(thunk.get());
        Assertions.assertNull(thunk.get());
        Assertions.assertNull(thunk.get());
        Assertions.assertEquals(1, invok.get());
    }
}