assertion-patterns

Assertion Patterns

Purpose

Transform T1-T4 violating assertions into real behavior verification. This skill provides pattern libraries for converting mock-based tests to tests that verify observable output.

When to Use

Load this skill when:

• Rewriting tests flagged by test-audit
• Generating verification scripts via bulwark-verify skill
• Implementing test-audit Step 7 rewrites

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Prerequisite Checks (T0) - CRITICAL

Before checking T1-T4 violations, verify these prerequisites. Tests failing these checks are "testing nothing real" - they pass but provide zero confidence.

T0.1: Production Module Imports

Test files MUST import functions from actual production modules.

Valid	Invalid
import { calculate } from '../src/calculator'	Function defined within test file
from calculator import add	def add(a, b): return a + b in test

Detection:

• Scan test file for function definitions
• Check if tested functions are imported vs defined inline
• Flag if test calls functions not imported from production code

Violation Response:

"Test defines production logic inline. Move {function_name} to production module and import it. Tests should verify production code, not self-defined code."

T0.2: Separation of Concerns

Test files MUST NOT contain functions representing production logic.

Allowed in test files:

• Test functions (test_*, it(), describe())
• Test helpers/fixtures (make_*, create_*, setup_*)
• Mock factories (mock_*, fake_*, stub_*)
• Pytest fixtures (@pytest.fixture)

Not allowed:

• Business logic functions
• Utility functions that should be in production
• Any function that would make sense in src/

Detection:

• Identify all function definitions in test file
• Check naming patterns against allowed prefixes
• Flag functions that don't match test/helper patterns

T0.3: Function Naming Conventions

Functions in test files should follow specific naming patterns.