It is very easy to write incomplete assertions when using some test frameworks. This rule enforces complete assertions in the following cases:

* Fest: ``++assertThat++`` is not followed by an assertion invocation
* AssertJ: ``++assertThat++`` is not followed by an assertion invocation
* Mockito: ``++verify++`` is not followed by a method invocation
* Truth: ``++assertXXX++`` is not followed by an assertion invocation

In such cases, what is intended to be a test doesn't actually verify anything

== Noncompliant Code Example

----
// Fest
boolean result = performAction();
// let's now check that result value is true
assertThat(result); // Noncompliant; nothing is actually checked, the test passes whether "result" is true or false

// Mockito
List mockedList = Mockito.mock(List.class);
mockedList.add("one");
mockedList.clear();
// let's check that "add" and "clear" methods are actually called
Mockito.verify(mockedList); // Noncompliant; nothing is checked here, oups no call is chained to verify()
----

== Compliant Solution

----
// Fest
boolean result = performAction();
// let's now check that result value is true
assertThat(result).isTrue();

// Mockito
List mockedList = Mockito.mock(List.class);
mockedList.add("one");
mockedList.clear();
// let's check that "add" and "clear" methods are actually called
Mockito.verify(mockedList).add("one");
Mockito.verify(mockedList).clear();
----

== Exceptions

Variable assignments and return statements are skipped to allow helper methods.

----
private BooleanAssert check(String filename, String key) {
  String fileContent = readFileContent(filename);
  performReplacements(fileContent);
  return assertThat(fileContent.contains(key)); // No issue is raised here
}

@Test
public void test() {
  check("foo.txt", "key1").isTrue();
  check("bar.txt", "key2").isTrue();
}
----