我在 BrickSortParallel 类中有两个静态方法。它们完全被单元测试覆盖。但我列出了一个静态块
static {...}
,Jacoco 的代码覆盖率只有 75%。这意味着什么?
public static int computeOddTaskCount(int length) {
if (length < 0) throw new IllegalArgumentException("Illegal argument value: " + length);
return isOdd(length) ? length >> 1 : abs(length - 1) >> 1;
}
public static int computeEvenTaskCount(int length) {
if (length < 0) throw new IllegalArgumentException("Illegal argument value: " + length);
return length >> 1;
}
以下是确保上述方法的完整代码覆盖率的测试用例:
class ComputeTaskCountTest {
private static final String ZERO_TASKS_EXPECTED = "Zero tasks expected.";
private static final String ONE_TASK_EXPECTED = "One task expected.";
private static final String HALF_TASKS_EXPECTED = "Half tasks expected.";
private static final String ILLEGAL_LENGTH_EXPECTED = "Illegal length expected.";
@Test
@DisplayName("BrickSortParallelTest.ComputeTaskCountTest.testZeroLength")
void testZeroLength() {
assertEquals(0, computeOddTaskCount(0), ZERO_TASKS_EXPECTED);
assertEquals(0, computeEvenTaskCount(0), ZERO_TASKS_EXPECTED);
}
@Test
@DisplayName("BrickSortParallelTest.ComputeTaskCountTest.testMinusOneLength")
void testMinusOneLength() {
assertThrows(
IllegalArgumentException.class, () -> computeOddTaskCount(-1), ILLEGAL_LENGTH_EXPECTED);
assertThrows(
IllegalArgumentException.class, () -> computeEvenTaskCount(-1), ILLEGAL_LENGTH_EXPECTED);
}
@Test
@DisplayName("BrickSortParallelTest.ComputeTaskCountTest.testMinusTwoLength")
void testMinusTwoLength() {
assertThrows(
IllegalArgumentException.class, () -> computeOddTaskCount(-2), ILLEGAL_LENGTH_EXPECTED);
assertThrows(
IllegalArgumentException.class, () -> computeEvenTaskCount(-2), ILLEGAL_LENGTH_EXPECTED);
}
@Test
@DisplayName("BrickSortParallelTest.ComputeTaskCountTest.testMinValueLength")
void testMinValueLength() {
assertThrows(
IllegalArgumentException.class,
() -> computeOddTaskCount(Integer.MIN_VALUE),
ILLEGAL_LENGTH_EXPECTED);
assertThrows(
IllegalArgumentException.class,
() -> computeEvenTaskCount(Integer.MIN_VALUE),
ILLEGAL_LENGTH_EXPECTED);
}
@Test
@DisplayName("BrickSortParallelTest.ComputeTaskCountTest.testOneValueLength")
void testOneValueLength() {
assertEquals(0, computeOddTaskCount(1), ZERO_TASKS_EXPECTED);
assertEquals(0, computeEvenTaskCount(1), ZERO_TASKS_EXPECTED);
}
@Test
@DisplayName("BrickSortParallelTest.ComputeTaskCountTest.testTwoValueLength")
void testTwoValueLength() {
assertEquals(0, computeOddTaskCount(2), ZERO_TASKS_EXPECTED);
assertEquals(1, computeEvenTaskCount(2), ONE_TASK_EXPECTED);
}
@Test
@DisplayName("BrickSortParallelTest.ComputeTaskCountTest.testThreeValueLength")
void testThreeValueLength() {
assertEquals(1, computeOddTaskCount(3), ONE_TASK_EXPECTED);
assertEquals(1, computeEvenTaskCount(3), ONE_TASK_EXPECTED);
}
@Test
@DisplayName("BrickSortParallelTest.ComputeTaskCountTest.testFourValueLength")
void testFourValueLength() {
assertEquals(1, computeOddTaskCount(4), ONE_TASK_EXPECTED);
assertEquals(2, computeEvenTaskCount(4), "Two tasks expected");
}
@Test
@DisplayName("BrickSortParallelTest.ComputeTaskCountTest.testMaxValueLength")
void testMaxValueLength() {
assertEquals(
Integer.MAX_VALUE / 2, computeOddTaskCount(Integer.MAX_VALUE), HALF_TASKS_EXPECTED);
assertEquals(
Integer.MAX_VALUE / 2, computeEvenTaskCount(Integer.MAX_VALUE), HALF_TASKS_EXPECTED);
}
@Test
@DisplayName("BrickSortParallelTest.ComputeTaskCountTest.testMaxValueLengthEven")
void testMaxValueLengthEven() {
assertEquals(
(Integer.MAX_VALUE - 2) / 2,
computeOddTaskCount(Integer.MAX_VALUE - 1),
HALF_TASKS_EXPECTED);
assertEquals(
(Integer.MAX_VALUE - 1) / 2,
computeEvenTaskCount(Integer.MAX_VALUE - 1),
HALF_TASKS_EXPECTED);
}
}
我在上面的测试课中遗漏了什么吗?
完整课程可在以下网址获得:
https://raw.githubusercontent.com/linusjf/DSAlgos/master/src/main/java/ds/BrickSortParallel.java
$ java --version
openjdk 11.0.8 2020-07-14
OpenJDK Runtime Environment (build 11.0.8+10)
OpenJDK 64-Bit Server VM (build 11.0.8+10, mixed mode)
Jacoco版本:0.85
从报告来看,静态块的圈复杂度为 2,并且仅覆盖一个分支,这意味着缺少一个 测试用例来覆盖这种可能性。
引用 Jacoco Github 上的 Marc R Hoffman :
“您的代码使用了断言关键字,这会产生静态初始值设定项:
static {};
descriptor: ()V
flags: (0x0008) ACC_STATIC
Code:
stack=1, locals=0, args_size=0
0: ldc #72 // class ds/BrickSortParallel
2: invokevirtual #73 // Method java/lang/Class.desiredAssertionStatus:()Z
5: ifne 12
8: iconst_1
9: goto 13
12: iconst_0
13: putstatic #31 // Field $assertionsDisabled:Z
16: return
LineNumberTable:
line 19: 0
StackMapTable: number_of_entries = 2
frame_type = 12 /* same */
frame_type = 64 /* same_locals_1_stack_item */
stack = [ int ]
这是一个已知的限制。解决方法是不使用断言。”
以下代码片段解决了这个难题:
@Generated
private void assertEquality(int size, int count) {
if (size != count)
throw new AssertionError("Size is not the same as count.");
}
它会抛出 AssertionError,但
@Generated
注释可以满足代码覆盖率要求。然而,这是一种解决方法。解决方案是等待 Jacoco 在字节代码中提供所需的断言过滤。