PHPUnit Test Naming Convention

The Rule

Every test method MUST start with it_ and form a grammatically correct English sentence when you replace underscores with spaces.

it_{verb}_{object}_{optional_qualifiers}

"it" is the grammatical subject — "it" = the feature/system under test.

"It returns 404 for a nonexistent record."
"It stores the entity and fires the expected event."
"It rejects the action when a precondition is not met."

✅ Correct

public function it_returns_200_when_record_is_found(): void {}
public function it_redirects_to_index_when_user_lacks_permission(): void {}
public function it_stores_entity_with_valid_payload(): void {}
public function it_rejects_invalid_status_for_task(): void {}
public function it_soft_deletes_parent_and_preserves_children(): void {}
public function it_sends_403_json_when_access_is_denied(): void {}
public function it_creates_line_item_and_attaches_it_to_parent(): void {}
public function it_calculates_total_price_excluding_tax(): void {}
public function it_authorized_user_can_delete_task(): void {} // ✅ reads: "it [is that an] authorized user can delete task"
public function it_unauthorized_user_cannot_delete_task(): void {} // ✅ same pattern

❌ Wrong — and why

Bad name	Problem	Fix
it_user_can_view_document	"it user" is not English	it_authorized_user_can_view_document
a_user_can_view_document	Doesn't start with it_	it_authorized_user_can_view_document
test_duplicates_are_removed	test_ prefix — use #[Test] attribute instead	it_removes_duplicate_statuses_in_response
test_it_can_access_create_task	Double prefix: test_it_	it_can_access_task_create_page
it_can_list_clients_index	Redundant "index" after verb "list"	it_lists_all_clients_on_index_page

The it_user_* smell

it_user_can_* was historically used for user-permission tests. The fix is NOT to rename to a_user_* — that just swaps one broken convention for another. The correct patterns are:

// For permission tests: keep "user" as a qualifier on the subject
it_authorized_user_can_delete_task()
it_unauthorized_user_cannot_delete_task()

// Or: drop the subject, make it about the outcome
it_deletes_task_when_user_has_delete_permission()
it_returns_403_when_user_lacks_delete_permission()

Attribute, Not Prefix

Never use test_ prefix. Always annotate with #[Test]:

// ❌
public function test_creates_record() {}

// ✅
#[Test]
public function it_creates_record(): void {}

Return Type

All test methods must declare : void.

Checklist When Writing a Test Name

1. Does it start with it_?
2. Read it aloud replacing underscores with spaces. Does it sound like a sentence?
3. Is the verb meaningful? (returns, stores, rejects, sends, deletes, redirects, calculates, creates, lists, shows)
4. Does the name reveal the scenario, not just the action? (it_rejects_payment_when_invoice_is_not_sent > it_cannot_add_payment)
5. Return type : void declared?

Audit Command

# Find non-conforming names (test_, a_user_, it_user_, no it_ prefix)
grep -rn "public function " tests/ --include="*.php" \
  | grep -vE "setUp|tearDown|__construct|protected |abstract " \
  | grep -vE "public function it_" \
  | grep -v "Browser/"