Document using AssertJ's satisfies together with extractingJsonPathNumberValue

[wimdeblauwe]

I am using extractingJsonPathNumberValue to test a double value in my JSON:

 assertThat(json.write(message))
   .extractingJsonPathNumberValue("@.stopTime.percentage").isEqualTo(0.16666666666666666)

However, this does not work because of different types:

org.opentest4j.AssertionFailedError:
Expecting:
<"0.16666666666666666 (BigDecimal@1c52552f)">
to be equal to:
<"0.16666666666666666 (Double@5dc769f9)">
but was not.
Expected :0.16666666666666666
Actual :0.16666666666666666

What is the recommended way to do this? Should there be other methods like extractingJsonPathDoubleValue or extractingJsonPathFloatValue that could return DoubleAssert or FloatAssert so that methods like isCloseTo can be used?

[wilkinsona]

We can consider adding some more methods, but I'm not sure that we need to increase the surface area of the API. You can use AssertJ's satisfies and your knowledge of the type of the Number to then use isCloseTo:

assertThat(json.write(message))
    .extractingJsonPathNumberValue("@.stopTime.percentage")
    .satisfies((number) -> assertThat(number.floatValue()).isCloseTo(0.16f, within(0.01f)));

[wimdeblauwe]

Using satisfies is indeed a very good way to do it. Maybe this could be added to the https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-testing.html#boot-features-testing-spring-boot-applications-testing-autoconfigured-json-tests documentation instead of adding those extra methods to the API ?