organize-tests

name	organize-tests
description	Organize tests by isolation requirements, adhering to PTY conventions and subprocess isolation patterns.

// Copyright (c) 2025 R3BL LLC. Licensed under Apache License, Version 2.0.

Skill: organize-tests

Organize tests by isolation requirements, adhering to PTY conventions and subprocess isolation patterns.

When to Use

• Adding new tests to the codebase.
• Refactoring existing tests.
• Organizing test modules and directories.
• Ensuring PTY tests follow the "Run with:" and deadlock prevention conventions.

Instructions

1. Identify Isolation Requirements

Choose the correct directory based on why the test needs isolation. This maintains low cognitive load for future developers.

See Taxonomy for directory details.

2. Follow PTY Conventions

PTY tests are complex and prone to deadlocks (especially on macOS). Strict adherence to naming, documentation, and resource management is mandatory.

See PTY Conventions for details.

3. Orchestrate Process Isolation

Tests that pollute global mock state (e.g., static Mutexes) must be isolated into a single subprocess and run sequentially.

See Examples for macro usage.

4. Wire Up Modules

Always ensure test modules are visible for both tests and documentation using #[cfg(any(test, doc))].

#[cfg(any(test, doc))]
pub mod unit_tests;
#[cfg(any(test, doc))]
pub mod process_isolated_tests;
#[cfg(any(test, doc))]
pub mod my_module_integration_tests;

5. Memory Size "Tripwire" Tests

When writing tests that assert the byte size of a struct (std::mem::size_of), you MUST gate the test or the assertion block with #[cfg(target_pointer_width = "64")] to ensure it only runs on 64-bit architectures. Struct sizes vary between 32-bit and 64-bit platforms due to pointer sizes.

#[test]
fn test_my_struct_size() {
    // TRIPWIRE: If you add or remove a field, this test will fail.
    // This reminds you to update the `GetMemSize` implementation.
    #[cfg(target_pointer_width = "64")]
    {
        assert_eq!(std::mem::size_of::<MyStruct>(), 184);
    }
}

Related Skills

• organize-modules: Use for general module structure and re-exports.
• write-documentation: Use for formatting "Run with:" blocks and intra-doc links.