9

我需要测试这个方法 - compare()。你能得到建议吗？我能做到多好（如果，如果，如果，其他所有部分）。

public class AbsFigure {

class AreaCompare implements Comparator<FigureGeneral> {

    @Override
    public int compare(FigureGeneral oneFigure, FigureGeneral twoFigure) {
        double firstValue = oneFigure.area();
        double secondValue = twoFigure.area();
        int result = 0;

        if (firstValue > secondValue)
            result = 1;
        else if (firstValue < secondValue)
            result = -1;
        else
            result = 0;

        return result;
    }
}

在此建议之后 - 我们有下一张照片（非常感谢你们！）：

public AreaCompare areaCompare = new AreaCompare();

@Test
public void testEqual() {
    FigureGeneral oneFigure = new Rectangle(2.0, 2.0, "triangle");
    FigureGeneral twoFigure = new Rectangle(2.0, 2.0, "rectangle");
        int result = areaCompare.compare(oneFigure, twoFigure);
        assertTrue("expected to be equal", result == 0);
}

@Test
public void testGreaterThan() {
    FigureGeneral oneFigure = new Triangle(2.0, 2.0, "triangle");
    FigureGeneral twoFigure = new Rectangle(1.0, 1.0, "rectangle");
        int result = areaCompare.compare(oneFigure, twoFigure);
        assertTrue("expected to be greater than", result >= 1);
}

@Test
public void testLessThan() {
    FigureGeneral oneFigure = new Rectangle(1.0, 1.0, "rectangle");
    FigureGeneral twoFigure = new Triangle(2.0, 2.0, "triangle");
        int result = areaCompare.compare(oneFigure, twoFigure);
        assertTrue("expected to be less than", result <= -1);

现在一切正常测试。

4

5 回答 5

17

只需实例化您的比较器类并传入对象：

public class Test extends TestCase {
    class AreaCompare implements Comparator<FigureGeneral> {

        @Override
        public int compare(FigureGeneral oneFigure, FigureGeneral twoFigure) {
            double firstValue = oneFigure.area();
            double secondValue = twoFigure.area();
            int result = 0;

            if (firstValue > secondValue) {
                result = 1;
            } else if (firstValue < secondValue) {
                result = -1;
            } else {
                result = 0;
            }

            return result;
        }
    }

    private final AreaCompare areaCompare = new AreaCompare();

    @Test
    public void testEqual() {
        FigureGeneral oneFigure = new FigureGeneral();
        FigureGeneral twoFigure = new FigureGeneral();
        int result = areaCompare.compare(oneFigure, twoFigure);
        assertTrue("expected to be equal", result == 0);
    }

    @Test
    public void testGreaterThan() {
        FigureGeneral oneFigure = new FigureGeneral();
        FigureGeneral twoFigure = new FigureGeneral();
        int result = areaCompare.compare(oneFigure, twoFigure);
        assertTrue("expected to be greater than", result >= 1);
    }

    @Test
    public void testLessThan() {
        FigureGeneral oneFigure = new FigureGeneral();
        FigureGeneral twoFigure = new FigureGeneral();
        int result = areaCompare.compare(oneFigure, twoFigure);
        assertTrue("expected to be less than", result <= -1);
    }
}
于 2013-01-03T18:33:30.547 回答
1

对我来说看起来很傻。也许摆脱result

class AreaCompare implements Comparator<FigureGeneral> {

    @Override
    public int compare(FigureGeneral oneFigure, FigureGeneral twoFigure) {
        double firstValue = oneFigure.area();
        double secondValue = twoFigure.area();
        if (firstValue > secondValue)
            return 1;
        else if (firstValue < secondValue)
            return -1;
        return 0;
    }
}

至少编写测试用例。每个返回值一个。

compare(a, b)应该有不同于compare(b, a) 或的符号

compare(a, b) == compare(b, a) == 0

于 2013-01-03T18:31:53.990 回答
1

我最近有一个类似的需求，并提出了一些辅助方法（虽然还没有作为 API 发布）。这是源代码：

https://github.com/SoftSmithy/softsmithy-lib/blob/master/softsmithy-lib-core/src/test/java/org/softsmithy/lib/Tests.java

这是一个使用这些实用方法的测试：

https://github.com/SoftSmithy/softsmithy-lib/blob/master/softsmithy-lib-core/src/test/java/org/softsmithy/lib/util/PositionableComparatorTest.java

于 2013-01-03T20:00:33.873 回答
1

最好测试合约而不是 -1/0/1 值（或更准确地说，任何正/零/负值）。这可以使用 Hamcrest 匹配器以非常简洁的方式完成。考虑以下示例：

import static org.hamcrest.Matchers.comparesEqualTo;
import static org.hamcrest.Matchers.greaterThan;
import static org.hamcrest.Matchers.lessThan;

public AreaCompare areaCompare = new AreaCompare();

@Test
public void testEqual() {
    FigureGeneral oneFigure = new Rectangle(2.0, 2.0, "triangle");
    FigureGeneral twoFigure = new Rectangle(2.0, 2.0, "rectangle");
    assertThat(oneFigre comparesEqualTo(twoFigure));
    assertThat(twoFigure, comparesEqualTo(oneFigure));
}

@Test
public void testGreaterThan() {
    FigureGeneral oneFigure = new Triangle(2.0, 2.0, "triangle");
    FigureGeneral twoFigure = new Rectangle(1.0, 1.0, "rectangle");
    assertThat(oneFigure, greaterThan(twoFigure));
}

@Test
public void testLessThan() {
    FigureGeneral oneFigure = new Rectangle(1.0, 1.0, "rectangle");
    FigureGeneral twoFigure = new Triangle(2.0, 2.0, "triangle");
    assertThat(oneFigure, lessThan(twoFigure));
}

因此，您不必记住哪个值代表什么，并且测试可以明确意图。

于 2015-11-11T23:45:22.190 回答
0

经过一点建议，良好的测试：

public AreaCompare areaCompare = new AreaCompare();

@Test
public void testEqual() {
    FigureGeneral oneFigure = new Rectangle(2.0, 2.0, "triangle");
    FigureGeneral twoFigure = new Rectangle(2.0, 2.0, "rectangle");
        int result = areaCompare.compare(oneFigure, twoFigure);
        assertTrue("expected to be equal", result == 0);
}

@Test
public void testGreaterThan() {
    FigureGeneral oneFigure = new Triangle(2.0, 2.0, "triangle");
    FigureGeneral twoFigure = new Rectangle(1.0, 1.0, "rectangle");
        int result = areaCompare.compare(oneFigure, twoFigure);
        assertTrue("expected to be greater than", result >= 1);
}

@Test
public void testLessThan() {
    FigureGeneral oneFigure = new Rectangle(1.0, 1.0, "rectangle");
    FigureGeneral twoFigure = new Triangle(2.0, 2.0, "triangle");
        int result = areaCompare.compare(oneFigure, twoFigure);
        assertTrue("expected to be less than", result <= -1);
}
于 2013-01-05T20:33:55.450 回答