Simplify Boolean Test Assertions
ID |
java.test_assertion_boolean_simplify |
Severity |
low |
Remediation Complexity |
medium |
Remediation Risk |
low |
Remediation Effort |
medium |
Resource |
Code Smell |
Language |
Java |
Tags |
best-practice, junit, testing |
Description
Reports assertTrue(!expr) calls that should be simplified to assertFalse(expr), and assertFalse(!expr) calls that should be simplified to assertTrue(expr).
Rationale
Using a negated expression inside assertTrue or assertFalse is unnecessarily complex. When the assertion fails, the error message is less informative because the negation obscures the intent. Using the complementary assertion method directly makes the test intent clear and improves failure diagnostics.
// Bad - negated assertion
assertTrue(!result.isEmpty());
assertFalse(!isValid);
// Bad - with message
assertTrue("should be empty", !list.isEmpty());Remediation
Replace assertTrue(!expr) with assertFalse(expr) and assertFalse(!expr) with assertTrue(expr).
// Good - direct assertion
assertFalse(result.isEmpty());
assertTrue(isValid);
// Good - with message
assertFalse("should be empty", list.isEmpty());