A library for test assertions on JSON payloads - for JUnit framework.
For such JSON:
{
"firstname": "Steve",
"lastname": "Jobs"
}
... an exact-match assertion would look like this:
@Test
public void simpleTest() {
// when
String actualJson = getSteveJobsJson();
// then
assertThat(response).matches(
new JazonMap()
.with("firstname", "Steve")
.with("lastname", "Jobs")
);
}
This assertion passes even though the items in the array are in different order.
The actualJson
:
{
"id": 95478,
"name": "Coca Cola",
"tags": ["sprite", "pepsi", "7up", "fanta", "dr pepper"]
}
The assertion:
assertThat(response).matches(
new JazonMap()
.with("id", 95478)
.with("name", "Coca Cola")
.with("tags", set("pepsi", "dr pepper", "sprite", "fanta", "7up"))
);
private Set<Object> set(Object... elements) {
HashSet<Object> result = new HashSet<>(elements.length);
result.addAll(asList(elements));
return result;
}
If you need, instead of exact-matching, you can define custom assertions using Predicates. Here for example, we used custom assertions:
- to check that a number is in given range -
(Integer id) -> id >= 0
- to check that a field matches a regex -
regex()
- to check that a field just exists, no matter of its value -
Objects::nonNull
The actualJson
:
{
"id": 95478,
"name": "Coca Cola",
"value": "133.30",
"updated_at": "1990-06-19T12:19:10Z"
}
The assertion:
assertThat(response).matches(
new JazonMap()
.with("id", (Integer id) -> id >= 0)
.with("name", "Coca Cola")
.with("value", regex("\\d+\\.\\d\\d"))
.with("updated_at", Objects::nonNull)
);
private Predicate<String> regex(String regex) {
return value -> value.matches(regex);
}
To avoid code duplication, you can extract your common wildcard-assertions to constants.
assertThat(response).matches(
new JazonMap()
.with("id", ANY_ID) // a constant
.with("name", "Coca Cola")
.with("value", "133.30")
.with("updated_at", ANY_ISO_DATETIME) // a constant
);
private static final Predicate<Integer> ANY_ID = (id) -> id >= 0;
private static final Predicate<String> ANY_ISO_DATETIME =
datetime -> datetime.matches("\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}Z");
To avoid code duplication even more, you can extract the parts of JSON. This will also
make your tests more readable.
Here in the examples we extract deal()
- a business object from sales domain.
assertThat(response).matches(deal("Coca Cola", "10.00"));
assertThat(response).matches(
asList(
deal("Coca Cola", "10.00"),
deal("Pepsi", "9.00"),
deal("Fanta", "10.00"),
deal("Sprite", "10.00"),
deal("Dr Pepper", "12.00")
)
);
private JazonMap deal(String name, String value) {
return new JazonMap()
.with("id", ANY_ID)
.with("name", name)
.with("value", value)
.with("updated_at", ANY_ISO_DATETIME);
}
You can check out the example tests in the code
Copyright 2019 Zendesk, Inc.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.