Numeric boundary: zero

Numeric boundary: max

Numeric boundary: just outside min

Numeric boundary: just outside max

Quantity boundary: min and max

Quantity: below minimum

Equivalence partitioning

String: empty description

String: whitespace-only

String: boundary lengths

String: over-length

Property-based test present

Hypothesis strategy for valid domain

Descriptive test names

Test independence

Expected exception assertions

Mutation-catching coverage

Test strategy documented

Empty collection test

Single element test

Two elements minimal interaction

All identical elements

Duplicates across sub-arrays

All unique elements

Null/undefined input

Empty string SKU

fast-check property test present

Idempotency property

Length invariant property

Mutation notes present

package.json with dependencies

Descriptive test names

Isolated tests

Unicode/special character SKU

Very large input test

Invalid initial transition

Acquire after Close

Double Close

Release without Acquire

Valid state sequence

Concurrent writes (race condition test)

sync.WaitGroup usage

Deadlock prevention: timeout

Capacity boundary: zero capacity

Capacity boundary: single connection

Repeated operations

State transition diagram documented

Concurrency scenarios documented

Standard library only

Descriptive test function names