问题

I'm using assertj-core 3.9.1, but I also tested this with the latest available to me, 3.16.1.

我正在使用 assertj-core 3.9.1，但我也测试了最新的版本，3.16.1。

I'm trying to make some assertj assertions a little cleaner. We often assert multiple subproperties at a non-trivial hierarchy level, for various kinds of objects. I've been using "extracting" to pull simple properties from an object, but what I'm trying to do now is a little more complicated, and it's not working. What I'm seeing SEEMS like a bug in assertj, but I'm not sure why it's doing what it's doing.

我试图使一些 assertj 断言更加简洁。我们经常在不太常见的层次结构层级上断言多个子属性，针对各种类型的对象。我一直在使用 "extracting" 从对象中提取简单的属性，但我现在尝试做的更复杂，却不起作用。我所看到的情况似乎是 assertj 的一个 bug，但我不确定为什么它会出现这种情况。

I'm starting with something like this:

我从类似于以下内容的东西开始：

assertThat(expression).at("/content/liability").asText()).isEqualTo("CRU");
assertThat(expression).at("/content/enterpriseType").asText()).isEqualTo("GBS");

I'd like to instead do something like this:

我想改成这样：

assertThat(expression)
    .extracting(jn -> jn.at("/content/liability").asText(),
                jn -> jn.at("/content/enterpriseType").asText())
	.containsExactly("CRU", "GBS");

This fails, basically saying that I expected "[]" (an empty list) to be equal to ["CRU", "GBS"].

这会失败，基本上是说我预期 "[]"（空列表）与 ["CRU", "GBS"] 相等。

I still have the original assertions above this, using the same expression, so I know the data is there. The expression returns a structure like this:

我仍然在上面有原始的断言，使用相同的表达式，所以我知道数据是存在的。该表达式返回以下结构：

{
  "content": {
    ...
    "enterpriseType": "GBS",
    ...
    "liability": "CRU",
    ...
  }
}

So, I then tried changing the assertion to this:

所以，我尝试将断言更改为以下内容：

assertThat(expression))
	.extracting(jn -> textAtPath(jn, "/content/liability"),
				jn -> textAtPath(jn, "/content/enterpriseType"))
	.containsExactly(tuple("CRU", "GBS"));

With:

使用以下代码：

private String textAtPath(JsonNode node, String path) {
	return node.at(path).asText();
}

And then I ran the test with a breakpoint in "textAtPath". What I saw there looked normal, until I looked closer. When I viewed the value of "node", I saw something that looked very much like the structure I showed above, but not quite:

然后，我在 "textAtPath" 中设置了断点运行测试。我在那里看到的东西看起来很正常，直到我仔细观察。当我查看 "node" 的值时，我看到的东西非常类似于上面我展示的结构，但不完全相同：

{
  ...
  "enterpriseType": "GBS",
  ...
  "liability": "CRU",
  ...
}

For some reason, the value passed to the lambda passed to "extracting()" was the CHILD node of the original structure.

出于某种原因，传递给 "extracting()" 的 lambda 的值是原始结构的子节点。

I tried changing the test so the two path strings were "/liability" and "/enterpriseType". The test passed. I'm not going to leave it like this, because this just doesn't make sense.

我尝试将测试更改为两个路径字符串分别是 "/liability" 和 "/enterpriseType"。测试通过了。我不会让它保持这样，因为这没有意义。

assertThat(expression).at("/content/liability").asText()).isEqualTo("CRU");
assertThat(expression).at("/content/enterpriseType").asText()).isEqualTo("GBS");

assertThat(expression)
    .extracting(jn -> jn.at("/content/liability").asText(),
                jn -> jn.at("/content/enterpriseType").asText())
	.containsExactly("CRU", "GBS");

{
  "content": {
	...
	"enterpriseType": "GBS",
	...
	"liability": "CRU",
	...
  }
}

assertThat(expression))
	.extracting(jn -> textAtPath(jn, "/content/liability"),
				jn -> textAtPath(jn, "/content/enterpriseType"))
	.containsExactly(tuple("CRU", "GBS"));

private String textAtPath(JsonNode node, String path) {
	return node.at(path).asText();
}

{
  ...
  "enterpriseType": "GBS",
  ...
  "liability": "CRU",
  ...
}

答案1

得分: 0

我相信这个问题在 https://github.com/joel-costigliola/assertj-core/issues/1954 中有讨论。

这里的微妙之处在于，如果表达式是可迭代的，那么 assertThat(expression) 将提供可迭代的断言，并且 extracting 将应用于可迭代的元素。

另一方面，如果 assertThat(expression) 返回对象断言，extracting 将应用于表达式。

我还强烈建议使用 JsonUnit 进行 JSON 断言。