codeprobe-testing

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Audits code for test quality and coverage issues — missing tests, test smells, poor test structure, mock abuse, coverage gaps, and fragile test data. Identifies weaknesses in the test suite and generates fix prompts. Trigger phrases: "test quality", "test audit", "test review", "coverage check", "missing tests", "test quality audit".

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NPX Install

npx skill4agent add roundingwell/codeprobe codeprobe-testing

SKILL.md Content

Standalone Mode

If invoked directly (not via the orchestrator), you must first:
  1. Read
    ../codeprobe/shared-preamble.md
    for the output contract, execution modes, and constraints.
  2. Load applicable reference files from
    ../codeprobe/references/
    based on the project's tech stack.
  3. Default to
    full
    mode unless the user specifies otherwise.

Test Quality & Coverage Auditor

Domain Scope

This sub-skill detects test quality and coverage issues across six categories:
  1. Missing Tests — Public methods without corresponding tests, critical business logic untested.
  2. Test Smells — Tests with no assertions, testing implementation details, brittle tests.
  3. Test Structure — Missing Arrange-Act-Assert separation, poor naming, testing too many things.
  4. Mock Abuse — Mocking the system under test, mock returning mocks, over-mocking.
  5. Coverage Gaps — No tests for error paths, authorization logic, edge cases.
  6. Test Data — Hardcoded IDs, fragile fixtures, environment-dependent tests.

What It Does NOT Flag

  • Missing tests for trivial getters/setters or pure DTOs — these add testing overhead without meaningful coverage.
  • Framework-generated test stubs that are empty but clearly scaffolded (e.g., Laravel's
    ExampleTest.php
    , Create React App's
    App.test.js
    ) — these are starting points, not abandoned tests.
  • Integration/E2E test suites that intentionally don't follow unit test conventions — different test levels have different design constraints.
  • Test execution speed — this sub-skill assesses test design quality, not runtime performance.
  • Tests in
    vendor/
    ,
    node_modules/
    , or other dependency directories.

Detection Instructions

Severity Ceiling

No finding from this sub-skill should ever be classified as Critical. Missing tests, even for critical business logic, are a maintainability and risk issue (Major), not a confirmed production defect. The highest severity this sub-skill may assign is Major. Follow the severity column in each detection table exactly — do not escalate beyond it.

Missing Tests

ID PrefixWhat to DetectHow to DetectSeverity
TEST
Public methods with no corresponding testScan source directories for public class methods. For each, check if a corresponding test file/method exists. Use test file naming conventions:
test_
,
_test.
,
.test.
,
Test[A-Z]
,
spec_
,
_spec.
,
.spec.
(matching
file_stats.py
patterns).
Major
TEST
Critical business logic untestedIdentify classes/methods handling payments, authentication, authorization, order processing, or data mutations. Check whether these have dedicated test coverage.Major
TEST
Edge cases unaddressedWhen tests exist for a method, check whether they cover: null/empty inputs, boundary values (0, -1, max), error cases, and the happy path. Flag methods with only happy-path tests.Minor

Test Smells

ID PrefixWhat to DetectHow to DetectSeverity
TEST
Tests with no assertionsSearch test methods for assertion calls (
assert
,
expect
,
should
,
verify
). Flag test methods that execute code but never assert on the outcome — they only verify "no exception thrown."
Major
TEST
Tests testing implementation detailsTests that mock every dependency and only verify call order/counts rather than outcomes. Tests that break when internal implementation changes but behavior stays the same. Look for excessive
->expects()->method()->with()
chains or
toHaveBeenCalledWith
without checking return values.
Minor
TEST
Brittle tests coupled to external stateTests that depend on database state not set up in the test, file system paths, network calls, or system time without mocking. Look for raw SQL in tests,
file_exists()
checks, HTTP calls without mocking.
Minor
TEST
Tests dependent on execution orderTests that pass individually but fail when run together (or vice versa). Look for shared mutable state between test methods: class-level properties modified in tests, database records not cleaned up.Major

Test Structure

ID PrefixWhat to DetectHow to DetectSeverity
TEST
Missing Arrange-Act-Assert separationTest methods where setup, execution, and assertion are interleaved rather than clearly separated. Multiple act+assert cycles in one test.Minor
TEST
Test names that don't describe the scenarioTest methods named
test1
,
testFunction
,
it_works
, or using generic names that don't describe the input condition and expected outcome. Good:
test_empty_cart_returns_zero_total
. Bad:
testCalculate
.
Minor
TEST
Single test testing too many thingsTest methods with 5+ assertions on unrelated outcomes, or that test multiple scenarios in sequence. Should be split into focused tests.Minor

Mock Abuse

ID PrefixWhat to DetectHow to DetectSeverity
TEST
Mocking the system under testTest creates a mock/partial mock of the class being tested. The test is testing the mock, not the actual code. Look for
$this->createPartialMock(ClassName::class)
or
jest.spyOn(sut, 'method')
where sut is the class being tested.
Major
TEST
Mock returning mocksMock objects configured to return other mock objects, creating deep mock chains.
$mock->method('getUser')->willReturn($userMock)
where
$userMock->method('getProfile')->willReturn($profileMock)
.
Major
TEST
Over-mocking making tests pass regardlessTests where every dependency is mocked and the mocks return exactly what the code expects, making the test a tautology. If you change the implementation logic, the test still passes because the mocks drive the result.Minor

Coverage Gaps

ID PrefixWhat to DetectHow to DetectSeverity
TEST
No tests for error/exception pathsMethods with try/catch blocks or error handling where tests only cover the success path. No test triggers the catch/error branch.Minor
TEST
No tests for authorization logicPermission checks, policy methods, gate definitions, middleware authorization — code that controls access but has no dedicated tests.Major
TEST
No edge case testsFunctions handling arrays/collections without tests for empty input. Numeric functions without tests for zero, negative, or boundary values. String functions without tests for empty string, unicode, or very long input.Minor

Test Data

ID PrefixWhat to DetectHow to DetectSeverity
TEST
Hardcoded IDs that may collideTests using hardcoded numeric IDs (
$userId = 42
,
id: 1
) instead of factory-generated values. These collide in parallel test runs or with seeded data.
Minor
TEST
Fragile factory/fixture setupTests with complex inline data setup that duplicates across multiple tests instead of using factories/fixtures/builders.Minor
TEST
Tests relying on specific database stateTests that assume certain records exist in the database without creating them in the test setup. Depends on seeders or previous test execution.Minor

ID Prefix & Fix Prompt Examples

All findings use the
TEST-
prefix, numbered sequentially:
TEST-001
,
TEST-002
, etc.

Fix Prompt Examples

  • "Write a test for
    OrderService@calculateTotal
    that covers: empty cart (expect 0), single item, multiple items, and item with discount. Use
    OrderFactory
    for test data. Place in
    tests/Unit/Services/OrderServiceTest.php
    ."
  • "The test
    test_user_can_login
    at
    tests/Feature/AuthTest.php:25
    has no assertions — it only calls the login endpoint. Add
    assertStatus(200)
    ,
    assertAuthenticated()
    , and
    assertJsonStructure(['token'])
    assertions."
  • "In
    tests/Unit/PaymentServiceTest.php:40
    , the mock chain is mocking too deeply. Create a concrete
    FakePaymentGateway
    that implements the gateway interface and returns predictable responses instead of nested mock returns."
  • "Replace the hardcoded user ID
    42
    in
    tests/Feature/OrderTest.php:15
    with
    User::factory()->create()->id
    to prevent test collisions in parallel test runs."