Improvement: Add a possibility to do good JSON assertions

Quick Description

In several projects we check for JSON data (REST, Google Analytics, etc.) These checks often result in a big unreadable text blob as an error message. We can do better. We should add a helper class to assert JSON Strings. If an assertion fails however we need a good message and overview on the JSON data inside our allure report.

User Story

As a test report reader, I want to see directly what is wrong with the JSON data, compared to the expected test data so that I don't waste time fiddling around with the data.

Upfront research

[ ] Check if there's a well maintained and useful json compare library for Java
[ ] Search for a good client side JSON diff library in JS
[ ] The JSON Diff Library should be hosted in a CDN

Functional Requirements

[ ] Add a helper class for JSON assertion
[ ] Add Methods for:
JSONAssert.assertEquals(actualData,expectedData)
JSONAssert.assertHas(actualData,jsonPath)
JSONAssert.assertEquals(data,jsonPath)
~JSONAssert.assertMatch(data,jsonPath,regExp)~ (Updated 2024-08-21)
think about what additional assertion methods could be useful
[ ] Give every assertion method the possibility to add a custom message
[ ] For the (non custom) error messages, keep in mind that they should work with and without allure
[ ] If the assertion fails, add a nice json diff view to the allure report before throwing an AssertionError.
[ ] For the diff view we should do a two column view marking the differences with colors.
[ ] Add support for different Comparison modes (Strict, StrictOrder, Lenient, nonExtensible) (Updated 2024-08-21)

Note: for the methods with jsonPath be reminded that those can have simple fields as well as complex json data as a result.

Documentation Requirements

[ ] Add a documentation page
[ ] Mention the allure diff view on the reports page of the wiki

Test Requirements

[ ] Write sufficient unit tests
[ ] Do a smoke test using the feature with an external library like the neodymium example (check if the allure view works)

Xceptance / neodymium-library