Question

我一直试图弄清楚如何使用JUnit，但我偶然发现了一个我不知道如何修复的问题。我写了一个名为OilTank的类，它可以通过getStoredOil（）等其他一些函数获取长期存储的参数和长容量。现在我试图运行一些测试而没有实例化类，一切都按预期运行。

import static org.junit.jupiter.api.Assertions.*;
import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

class OilTankTest {

    @Test
    public void testIsValidStoredOil_InRange() {
        assertTrue(OilTank.isValidStoredOil(100, 150));
    }

    @Test
    public void testIsValidStoredOil_TooHigh() {
        assertFalse(OilTank.isValidStoredOil(150, 100));
    }

    @Test
    public void testIsValidStoredOil_Negative() {
        assertFalse(OilTank.isValidStoredOil(-100, 150));
    }
}

在这种情况下，我的测试运行正常，但是当我尝试这个时，我得到了预期的结果：

...
class OilTankTest {

    OilTank tank_cap100_stored50;

    @BeforeEach
    void setUp() throws Exception {
        tank_cap100_stored50 = new OilTank(50,100);
    }

    @Test
    public void testIsValidStoredOil_InRange() {
        assertTrue(OilTank.isValidStoredOil(100, 150));
    }

    @Test
    public void testIsValidStoredOil_TooHigh() {
        assertFalse(OilTank.isValidStoredOil(150, 100));
    }

    @Test
    public void testIsValidStoredOil_Negative() {
        assertFalse(OilTank.isValidStoredOil(-100, 150));
    }
    @Test
    public void testSetStoredOil_SingleCase() {
        tank_cap100_stored50.setStoredOil(97);
        assertEquals(97,tank_cap100_stored50.getStoredOil());
    }

}

所有四项测试都失败了。我认为至少前三个会成功，所以我不确定我做错了什么。

提前感谢您的回复！

编辑：这里是OilTank类的代码。

public class OilTank {

    public OilTank(long storedOil, long capacity){
        assert isValidStoredOil(storedOil, this.getCapacity());
        assert isValidCapacity(capacity);
        this.storedOil = storedOil;
        this.capacity = capacity;
    }

    public long getStoredOil() {
        return this.storedOil;
    }

    public void setStoredOil(long storedOil) {
        assert isValidStoredOil(storedOil, this.getCapacity());
        this.storedOil = storedOil;
    }

    public static boolean isValidStoredOil(long storedOil, long capacity){
        return (storedOil >= 0) && (storedOil <= capacity);
    }

    private long storedOil;

    public static boolean isValidCapacity(long capacity) {
        return capacity > 0;
    }

    private final long capacity;
}

为了完成失败追踪：

java.lang.AssertionError
    at OilTank.<init>(OilTank.java:31)
    at OilTankTest.setUp(OilTankTest.java:23)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:389)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:115)
    at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.invokeMethodInExtensionContext(ClassTestDescriptor.java:289)
    at org.junit.jupiter.engine.descriptor.ClassTestDescriptor.lambda$synthesizeBeforeEachMethodAdapter$11(ClassTestDescriptor.java:277)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$null$2(TestMethodTestDescriptor.java:132)
    at org.junit.jupiter.engine.execution.ThrowableCollector.execute(ThrowableCollector.java:40)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeBeforeMethodsOrCallbacksUntilExceptionOccurs(TestMethodTestDescriptor.java:152)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeBeforeEachMethods(TestMethodTestDescriptor.java:131)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:106)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:57)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$execute$3(HierarchicalTestExecutor.java:83)
    at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:77)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$null$2(HierarchicalTestExecutor.java:92)
    at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)
    at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
    at java.util.Iterator.forEachRemaining(Iterator.java:116)
    at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
    at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
    at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
    at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
    at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
    at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
    at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$execute$3(HierarchicalTestExecutor.java:92)
    at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:77)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$null$2(HierarchicalTestExecutor.java:92)
    at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)
    at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
    at java.util.Iterator.forEachRemaining(Iterator.java:116)
    at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1801)
    at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
    at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
    at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
    at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
    at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
    at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:418)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.lambda$execute$3(HierarchicalTestExecutor.java:92)
    at org.junit.platform.engine.support.hierarchical.SingleTestExecutor.executeSafely(SingleTestExecutor.java:66)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:77)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:51)
    at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:43)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:170)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:154)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:90)
    at org.eclipse.jdt.internal.junit5.runner.JUnit5TestReference.run(JUnit5TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:538)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:760)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:460)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:206)

Answer 1

You OilTank构造函数使用getter来检索尚未设置的值

assert isValidStoredOil(storedOil, this.getCapacity());

尝试使用传入的变量

定义实例后，JUnit测试失败

1 个答案: