TruthGetOrDefault
Asserting on getOrDefault is unclear; prefer containsEntry or doesNotContainKey

The problem

Expectation of Truth.assertThat(map.getOrDefault(key, defaultValue)).isEqualTo(expectedValue) is unclear if the defaultValue is same as expectedValue. If the test passes, its hard to say if map contained key, expectedValue as an entry. Most likely, developer intended to verify that map doesn’t contain 'key or perhaps map key isn’t mapped to defaultValue.

Additionally, same assertion can be simplified if defaultValue and expectedValue are different constants to Truth.assertThat(map.get(key)).isEqualTo(expectedValue).

That is, prefer this:

public static void doSomething(Map<String, String> map, String key, String expectedValue) {
  assertThat(map.get(key)).isEqualTo(expectedValue);
  assertThat(map).doesNotContainKey(key);
  assertThat(map).containsEntry(key, expectedValue);
}

to this:

public static void doSomething(Map<String, String> map, String key, String defaultValue, String expectedValue) {
  assertThat(map.getOrDefault(key, defaultValue)).isEqualTo(expectedValue);
}

Suppression

Suppress false positives by adding the suppression annotation @SuppressWarnings("TruthGetOrDefault") to the enclosing element.