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TEST005-assert-count — Too Many Assertions in One Test

Dimension: TestSmell Default severity: Low Languages: All Last reviewed: 2026-05-06

What it detects​

For every test function (is_test == true), counts assertion tokens in the function body using the same pattern as TEST002-no-asserts. If the count exceeds the threshold (default 10), a finding is emitted.

Configuration​

[rules."TEST005-assert-count"]
threshold = 10   # default

Why it matters​

A test that makes many unrelated assertions is hard to understand and diagnose on failure — you must read the entire test to determine which assertion failed and why. Each test should verify a single behaviour.

Example — flagged​

def test_everything():
    assert 1 == 1
    assert 2 == 2
    # ... 9 more asserts
    assert 11 == 11   # ← 11 assertions > threshold, flagged

Example — not flagged​

def test_addition():
    assert add(1, 2) == 3   # single focused assertion, clean

Fix guidance​

  • Split the overloaded test into multiple smaller tests, each with a descriptive name indicating what it verifies.
  • Group related assertions into a dedicated helper or use parameterised tests.

Implementation​