java For循环和太多if-else如何测试

Question

我有一个这样的代码

List insert;
List update;
List delete
for(SomeObject someObj : someObjects){
    if(isNew){
        insert.add()
    }
    else if(isUpdate){
        update.add();
    }
    if(isDelete){
        delete.add()
    }
}

//call update insert delete functions

问题是这段代码不稳定，因为update insert delete都是void方法。 我的问题是，我是否应该考虑循环遍历三次，然后获取列表来测试是否过滤每个类型的结果的逻辑都在工作？成本没有我预期的那么高<；列表中有100个元素

Answer 1

你可以查一下

(sum of lists sizes after) == (sum of lists sizes before) + someObjects.size();

Answer 2

这里的关键是能够控制依赖项并访问该方法所作用的状态

以下是一个例子，说明：

interface SomeDao {
    void add(SomeObject object);
    void update(SomeObject object);
    void delete(SomeObject object);
}

class SomeDaoStub implements SomeDao {
    @Override public void add(SomeObject object) {}
    @Override public void update(SomeObject object) {}
    @Override public void delete(SomeObject object) {}
}

class SomeObject {
    private final boolean isNew;
    private final boolean isUpdated;
    private final boolean isDeleted;
    SomeObject(boolean isNew, boolean isUpdated, boolean isDeleted) {
        this.isNew = isNew;
        this.isUpdated = isUpdated;
        this.isDeleted = isDeleted;
    }
    public boolean isNew() {
        return isNew;
    }
    public boolean isUpdated() {
        return isUpdated;
    }
    public boolean isDeleted() {
        return isDeleted;
    }
}

public void doSomethingComplicatedWithListsInAForLoop(Iterable<SomeObject> someObjects, SomeDao dao) {
    for (SomeObject someObject : someObjects) {
        if (someObject.isNew()) {
            dao.add(someObject);
        } else if (someObject.isUpdated()) {
            dao.update(someObject);
        } else if (someObject.isDeleted()) {
            dao.delete(someObject);
        }
    }
}

@Test
public void itDeletesObjectsMarkedToBeDeleted() {
    final List<SomeObject> actualDeletedObjects = new ArrayList<>();
    List<SomeObject> expectedDeletedObjects = Arrays.asList(
            new SomeObject(false, false, true),
            new SomeObject(false, false, true),
            new SomeObject(false, false, true)
    );
    SomeDao theDao = new SomeDaoStub() {
        @Override
        public void delete(SomeObject object) {
            actualDeletedObjects.add(object);
        }
    };
    doSomethingComplicatedWithListsInAForLoop(expectedDeletedObjects, theDao);
    assertEquals(expectedDeletedObjects, actualDeletedObjects);
}

我能弄清楚doSomethingComplicatedWithListsInAForLoop操作了什么的唯一原因是因为我能控制它的依赖关系，也就是说，在这个例子中，SomeDao

您可能会发现测试方法很困难，因为它会调用无法注入的状态