Guava testlib中AbstractPackageSanityTests异常的含义
Meaning of AbstractPackageSanityTests exceptions in Guava testlib
我正在使用 Guava Testlib 的 AbstractPackageSanityTests，但我只是不明白我得到的异常。那么它们是什么意思呢？我需要更改什么来解决这些问题？
这是我的测试class:
package be.fror.racetrack;
import com.google.common.testing.AbstractPackageSanityTests;
public class PackageSanityTests extends AbstractPackageSanityTests {
public PackageSanityTests() {
publicApiOnly();
}
}
这些是我在 运行 测试用例时遇到的错误。
Running be.fror.racetrack.PackageSanityTests
Tests run: 3, Failures: 2, Errors: 0, Skipped: 0, Time elapsed: 1.21 sec <<< FAILURE!
testNulls(be.fror.racetrack.PackageSanityTests) Time elapsed: 0.554 sec <<< FAILURE!
junit.framework.AssertionFailedError: Error in automated nulls test of class be.fror.racetrack.Racer
If the class is better tested explicitly, you can add testNulls() to be.fror.racetrack.RacerTest
at com.google.common.testing.AbstractPackageSanityTests.sanityError(AbstractPackageSanityTests.java:288)
at com.google.common.testing.AbstractPackageSanityTests.testNulls(AbstractPackageSanityTests.java:215)
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:483)
at junit.framework.TestCase.runTest(TestCase.java:176)
at junit.framework.TestCase.runBare(TestCase.java:141)
at junit.framework.TestResult.protect(TestResult.java:122)
at junit.framework.TestResult.runProtected(TestResult.java:142)
at junit.framework.TestResult.run(TestResult.java:125)
at junit.framework.TestCase.run(TestCase.java:129)
at junit.framework.TestSuite.runTest(TestSuite.java:252)
at junit.framework.TestSuite.run(TestSuite.java:247)
at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:86)
at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:252)
at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:141)
at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:112)
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:483)
at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:189)
at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:165)
at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:85)
at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:115)
at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:75)
Caused by: junit.framework.AssertionFailedError: Can't find or create a sample instance for type 'be.fror.racetrack.Vector'; please provide one using NullPointerTester.setDefault()
at junit.framework.Assert.fail(Assert.java:57)
at junit.framework.Assert.assertTrue(Assert.java:22)
at com.google.common.testing.NullPointerTester.buildParamList(NullPointerTester.java:365)
at com.google.common.testing.NullPointerTester.testParameter(NullPointerTester.java:336)
at com.google.common.testing.NullPointerTester.testMethodParameter(NullPointerTester.java:210)
at com.google.common.testing.NullPointerTester.testMethod(NullPointerTester.java:178)
at com.google.common.testing.NullPointerTester.testStaticMethods(NullPointerTester.java:124)
at com.google.common.testing.ClassSanityTester.doTestNulls(ClassSanityTester.java:227)
at com.google.common.testing.AbstractPackageSanityTests.testNulls(AbstractPackageSanityTests.java:213)
... 25 more
testEquals(be.fror.racetrack.PackageSanityTests) Time elapsed: 0.127 sec <<< FAILURE!
junit.framework.AssertionFailedError: Error in automated equals test of class be.fror.racetrack.Racer
If the class is better tested explicitly, you can add testEquals() to be.fror.racetrack.RacerTest
at com.google.common.testing.AbstractPackageSanityTests.sanityError(AbstractPackageSanityTests.java:288)
at com.google.common.testing.AbstractPackageSanityTests.testEquals(AbstractPackageSanityTests.java:251)
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:483)
at junit.framework.TestCase.runTest(TestCase.java:176)
at junit.framework.TestCase.runBare(TestCase.java:141)
at junit.framework.TestResult.protect(TestResult.java:122)
at junit.framework.TestResult.runProtected(TestResult.java:142)
at junit.framework.TestResult.run(TestResult.java:125)
at junit.framework.TestCase.run(TestCase.java:129)
at junit.framework.TestSuite.runTest(TestSuite.java:252)
at junit.framework.TestSuite.run(TestSuite.java:247)
at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:86)
at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:252)
at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:141)
at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:112)
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:483)
at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:189)
at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:165)
at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:85)
at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:115)
at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:75)
Caused by: com.google.common.testing.ClassSanityTester$ParameterNotInstantiableException: Cannot determine value for parameter be.fror.racetrack.Vector arg1 of be.fror.racetrack.Racer.public static be.fror.racetrack.Racer be.fror.racetrack.Racer.startingAtWithVelocity(be.fror.racetrack.Player,be.fror.racetrack.Vector,be.fror.racetrack.Vector)
at com.google.common.testing.ClassSanityTester.generateDummyArg(ClassSanityTester.java:672)
at com.google.common.testing.ClassSanityTester.testEqualsUsing(ClassSanityTester.java:581)
at com.google.common.testing.ClassSanityTester.doTestEquals(ClassSanityTester.java:323)
at com.google.common.testing.AbstractPackageSanityTests.testEquals(AbstractPackageSanityTests.java:249)
... 25 more
由于这些异常提到了 Racer 和 Vector，因此它们是：
Vector.java（还没有VectorTest.java）：
package be.fror.racetrack;
import java.util.Objects;
public final class Vector {
// Factory methods
public static Vector zero() { return new Vector(0, 0); }
public static Vector of(int x, int y) { return new Vector(x, y); }
public static Vector copyOf(Vector other) {
if (other == null) { throw new NullPointerException(); }
// Vector is immutable. Don't make unuseful copies.
return other;
}
// Data
private final int x;
private final int y;
private Vector(int x, int y) { this.x = x; this.y = y; }
public int getX() { return x; }
public int getY() { return y; }
// Business
public Vector add(Vector other) { return of(x + other.x, y + other.y); }
// Overriding Object
@Override public boolean equals(Object obj) {
if (obj instanceof Vector) {
Vector other = (Vector) obj;
return x == other.x && y == other.y;
}
return false;
}
@Override public int hashCode() { return Objects.hash(x, y); }
@Override public String toString() { return String.format("(%d,%d)", x, y); }
}
Racer.java（还没有RacerTest.java）：
package be.fror.racetrack;
/**
*
* @author Olivier Grégoire
*/
public final class Racer {
// Factory methods
public static Racer startingAt(Player player, Vector position) { return startingAtWithVelocity(player, position, Vector.zero()); }
public static Racer startingAtWithVelocity(Player player, Vector position, Vector velocity) {
if (player == null || position == null || velocity == null) { throw new NullPointerException();}
return new Racer(player, position, velocity);
}
// Data
private final Player player;
private Vector position;
private Vector velocity;
private Racer(Player player, Vector position, Vector velocity) {
this.player = player;
this.position = position;
this.velocity = velocity;
}
public Player getPlayer() { return player; }
public Vector getPosition() { return position; }
public Vector getVelocity() { return velocity; }
public void accelerateAndMove(Direction direction) {
velocity = velocity.add(direction.asVector());
position = position.add(velocity);
}
// Overriding Object
@Override public boolean equals(Object obj) {
if (obj instanceof Racer) { return super.equals(obj); }
return false;
}
@Override public int hashCode() { return super.hashCode(); }
@Override public String toString() { return String.format("Racer{position=%s, velocity=%s}", position, velocity); }
}
对于testEquals的问题，"right"的解决方案大概是你的PackageSanityTests()构造函数调用setDistinctValues(Vector.class, Vector.zero(), Vector.of(1, 1)).
这里的想法是，为了测试 Racer.equals()，测试需要创建 Racer 的实例。要创建实例，他们需要调用 Racer 上的静态工厂方法之一。为此，除其他外，他们需要 Vector —— 两个不同的 Vector 对象，不少于此。但是，尽管测试足够聪明，可以在 Racer 上寻找静态工厂方法，但它们还不够聪明，无法在 Vector.
上寻找静态工厂方法。
我认为就是这样，无论如何。这里有足够多的魔法层次，我可能记错了。
我正在使用 Guava Testlib 的 AbstractPackageSanityTests，但我只是不明白我得到的异常。那么它们是什么意思呢？我需要更改什么来解决这些问题？
这是我的测试class:
package be.fror.racetrack;
import com.google.common.testing.AbstractPackageSanityTests;
public class PackageSanityTests extends AbstractPackageSanityTests {
public PackageSanityTests() {
publicApiOnly();
}
}
这些是我在 运行 测试用例时遇到的错误。
Running be.fror.racetrack.PackageSanityTests
Tests run: 3, Failures: 2, Errors: 0, Skipped: 0, Time elapsed: 1.21 sec <<< FAILURE!
testNulls(be.fror.racetrack.PackageSanityTests) Time elapsed: 0.554 sec <<< FAILURE!
junit.framework.AssertionFailedError: Error in automated nulls test of class be.fror.racetrack.Racer
If the class is better tested explicitly, you can add testNulls() to be.fror.racetrack.RacerTest
at com.google.common.testing.AbstractPackageSanityTests.sanityError(AbstractPackageSanityTests.java:288)
at com.google.common.testing.AbstractPackageSanityTests.testNulls(AbstractPackageSanityTests.java:215)
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:483)
at junit.framework.TestCase.runTest(TestCase.java:176)
at junit.framework.TestCase.runBare(TestCase.java:141)
at junit.framework.TestResult.protect(TestResult.java:122)
at junit.framework.TestResult.runProtected(TestResult.java:142)
at junit.framework.TestResult.run(TestResult.java:125)
at junit.framework.TestCase.run(TestCase.java:129)
at junit.framework.TestSuite.runTest(TestSuite.java:252)
at junit.framework.TestSuite.run(TestSuite.java:247)
at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:86)
at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:252)
at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:141)
at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:112)
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:483)
at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:189)
at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:165)
at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:85)
at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:115)
at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:75)
Caused by: junit.framework.AssertionFailedError: Can't find or create a sample instance for type 'be.fror.racetrack.Vector'; please provide one using NullPointerTester.setDefault()
at junit.framework.Assert.fail(Assert.java:57)
at junit.framework.Assert.assertTrue(Assert.java:22)
at com.google.common.testing.NullPointerTester.buildParamList(NullPointerTester.java:365)
at com.google.common.testing.NullPointerTester.testParameter(NullPointerTester.java:336)
at com.google.common.testing.NullPointerTester.testMethodParameter(NullPointerTester.java:210)
at com.google.common.testing.NullPointerTester.testMethod(NullPointerTester.java:178)
at com.google.common.testing.NullPointerTester.testStaticMethods(NullPointerTester.java:124)
at com.google.common.testing.ClassSanityTester.doTestNulls(ClassSanityTester.java:227)
at com.google.common.testing.AbstractPackageSanityTests.testNulls(AbstractPackageSanityTests.java:213)
... 25 more
testEquals(be.fror.racetrack.PackageSanityTests) Time elapsed: 0.127 sec <<< FAILURE!
junit.framework.AssertionFailedError: Error in automated equals test of class be.fror.racetrack.Racer
If the class is better tested explicitly, you can add testEquals() to be.fror.racetrack.RacerTest
at com.google.common.testing.AbstractPackageSanityTests.sanityError(AbstractPackageSanityTests.java:288)
at com.google.common.testing.AbstractPackageSanityTests.testEquals(AbstractPackageSanityTests.java:251)
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:483)
at junit.framework.TestCase.runTest(TestCase.java:176)
at junit.framework.TestCase.runBare(TestCase.java:141)
at junit.framework.TestResult.protect(TestResult.java:122)
at junit.framework.TestResult.runProtected(TestResult.java:142)
at junit.framework.TestResult.run(TestResult.java:125)
at junit.framework.TestCase.run(TestCase.java:129)
at junit.framework.TestSuite.runTest(TestSuite.java:252)
at junit.framework.TestSuite.run(TestSuite.java:247)
at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:86)
at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:252)
at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:141)
at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:112)
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:483)
at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:189)
at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:165)
at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:85)
at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:115)
at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:75)
Caused by: com.google.common.testing.ClassSanityTester$ParameterNotInstantiableException: Cannot determine value for parameter be.fror.racetrack.Vector arg1 of be.fror.racetrack.Racer.public static be.fror.racetrack.Racer be.fror.racetrack.Racer.startingAtWithVelocity(be.fror.racetrack.Player,be.fror.racetrack.Vector,be.fror.racetrack.Vector)
at com.google.common.testing.ClassSanityTester.generateDummyArg(ClassSanityTester.java:672)
at com.google.common.testing.ClassSanityTester.testEqualsUsing(ClassSanityTester.java:581)
at com.google.common.testing.ClassSanityTester.doTestEquals(ClassSanityTester.java:323)
at com.google.common.testing.AbstractPackageSanityTests.testEquals(AbstractPackageSanityTests.java:249)
... 25 more
由于这些异常提到了 Racer 和 Vector，因此它们是：
Vector.java（还没有VectorTest.java）：
package be.fror.racetrack;
import java.util.Objects;
public final class Vector {
// Factory methods
public static Vector zero() { return new Vector(0, 0); }
public static Vector of(int x, int y) { return new Vector(x, y); }
public static Vector copyOf(Vector other) {
if (other == null) { throw new NullPointerException(); }
// Vector is immutable. Don't make unuseful copies.
return other;
}
// Data
private final int x;
private final int y;
private Vector(int x, int y) { this.x = x; this.y = y; }
public int getX() { return x; }
public int getY() { return y; }
// Business
public Vector add(Vector other) { return of(x + other.x, y + other.y); }
// Overriding Object
@Override public boolean equals(Object obj) {
if (obj instanceof Vector) {
Vector other = (Vector) obj;
return x == other.x && y == other.y;
}
return false;
}
@Override public int hashCode() { return Objects.hash(x, y); }
@Override public String toString() { return String.format("(%d,%d)", x, y); }
}
Racer.java（还没有RacerTest.java）：
package be.fror.racetrack;
/**
*
* @author Olivier Grégoire
*/
public final class Racer {
// Factory methods
public static Racer startingAt(Player player, Vector position) { return startingAtWithVelocity(player, position, Vector.zero()); }
public static Racer startingAtWithVelocity(Player player, Vector position, Vector velocity) {
if (player == null || position == null || velocity == null) { throw new NullPointerException();}
return new Racer(player, position, velocity);
}
// Data
private final Player player;
private Vector position;
private Vector velocity;
private Racer(Player player, Vector position, Vector velocity) {
this.player = player;
this.position = position;
this.velocity = velocity;
}
public Player getPlayer() { return player; }
public Vector getPosition() { return position; }
public Vector getVelocity() { return velocity; }
public void accelerateAndMove(Direction direction) {
velocity = velocity.add(direction.asVector());
position = position.add(velocity);
}
// Overriding Object
@Override public boolean equals(Object obj) {
if (obj instanceof Racer) { return super.equals(obj); }
return false;
}
@Override public int hashCode() { return super.hashCode(); }
@Override public String toString() { return String.format("Racer{position=%s, velocity=%s}", position, velocity); }
}
对于testEquals的问题，"right"的解决方案大概是你的PackageSanityTests()构造函数调用setDistinctValues(Vector.class, Vector.zero(), Vector.of(1, 1)).
这里的想法是，为了测试 Racer.equals()，测试需要创建 Racer 的实例。要创建实例，他们需要调用 Racer 上的静态工厂方法之一。为此，除其他外，他们需要 Vector —— 两个不同的 Vector 对象，不少于此。但是，尽管测试足够聪明，可以在 Racer 上寻找静态工厂方法，但它们还不够聪明，无法在 Vector.
我认为就是这样，无论如何。这里有足够多的魔法层次，我可能记错了。