Why is this an issue?

Describing, setting error message or adding a comparator in AssertJ must be done before calling the assertion, otherwise, settings will not be taken into account.

This rule raises an issue when one of the method (with all similar methods):

is called without calling an AssertJ assertion afterward.

Noncompliant code example

assertThat(actual).isEqualTo(expected).as("Description"); // Noncompliant
assertThat(actual).isEqualTo(expected).withFailMessage("Fail message"); // Noncompliant
assertThat(actual).isEqualTo(expected).usingComparator(new CustomComparator()); // Noncompliant

Compliant solution

assertThat(actual).as("Description").isEqualTo(expected);
assertThat(actual).withFailMessage("Fail message").isEqualTo(expected);
assertThat(actual).usingComparator(new CustomComparator()).isEqualTo(expected);

Resources