Swift Testing Pro

What it does

When your agent uses it

• Reviewing projects that use Swift Testing
• Tasks that involve iOS development

Example prompts

• “/swift-testing-pro”

Workflow steps

5 steps, taken from the first numbered list in SKILL.md.

1. 1Ensure tests follow core Swift Testing conventions using references/core-rules.md.
2. 2Validate test structure, assertions, dependency injection, and other best practices using references/writing-better-tests.md.
3. 3Check async tests, confirmations, time limits, actor isolation, and networking mocks using references/async-tests.md.
4. 4Ensure new features like raw identifiers, test scopes, exit tests, and attachments are used correctly using references/new-features.md.
5. 5If migrating from XCTest, follow the conversion guidance in references/migrating-from-xctest.md.

What it can do on your machine

Read from SKILL.md and the folder at commit 2d6bba1. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  No scripts in the folder and no shell commands in SKILL.md (its code samples are swift).

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Swift Testing Pro loads about 1.1k tokens when it runs, and up to ~10k if it reads all its reference files. Until then it costs about 44 tokens; SKILL.md has 495 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~44

When it runs · the whole SKILL.md, loaded when a task matches

~1.1k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~10k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from twostraws/Swift-Testing-Agent-Skill at commit 2d6bba1, republished under its MIT licence (© twostraws). 495 words, ~1,075 tokens.

name

swift-testing-pro

description

Writes, reviews, and improves Swift Testing code using modern APIs and best practices. Use when reading, writing, or reviewing projects that use Swift Testing.

license

MIT

metadata.author

Paul Hudson

metadata.version

1.0

// Before
class UserTests: XCTestCase {

// After
struct UserTests {

// Before
XCTAssertEqual(user.name, "Taylor")

// After
#expect(user.name == "Taylor")

// Before
#expect(users.isEmpty == false)
let first = users.first!

// After
let first = try #require(users.first)

© twostraws, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 10 other files (references, assets) in swift-testing-pro of twostraws/Swift-Testing-Agent-Skill.

• SKILL.md
• .claude-plugin/plugin.json
• agents/openai.yaml
• assets/swift-testing-pro-icon.png
• assets/swift-testing-pro-icon.svg
• references/async-tests.md
• references/core-rules.md
• references/migrating-from-xctest.md
• references/new-features.md
• references/writing-better-tests.md
• skills

Open the folder on GitHubat commit 2d6bba1