Swift Cheat Sheet

Swift cheat sheet with real commands and snippets for setup, core workflows, debugging, and production-safe automation patterns. If you are working across tools, pair this with the SQLite Cheat Sheet and Scala Cheat Sheet.

Setup and Tooling

Goal: Install and verify language toolchain

# Run swift command
swift --version

# Run swift command
swift package init --type executable

# Run swift command
swift package resolve

Core Workflows

Goal: Run and build source code

# Execute swift workflow
swift run

# Execute swift workflow
swift build

Goal: Use a practical code snippet

import Foundation

struct User {
    let id: Int
    let name: String
}

let user = User(id: 1, name: "Rem")
print(user.name)

Testing and Formatting

Goal: Run automated tests

# Execute test-related command
swift test

# Execute test-related command
swift test --parallel

Goal: Run lint and formatter checks

# Execute quality command
swift format .

# Execute quality command
swift lint

Automation and CI

Goal: Create a repeatable CI shell step

# Run strict shell mode for CI step
set -euo pipefail

# Install dependencies deterministically
npm ci || pip install -r requirements.txt || true

# Run tests and fail fast on errors
swift test

Debugging and Troubleshooting

Goal: Trace runtime issues

# Print runtime and package manager versions
node --version || python --version || true

# Search stack traces and TODO markers
rg "Traceback|Exception|TODO" .

# Re-run tests with verbose output
swift test -v || swift test --verbose || true

Common Gotchas

• Pin Swift language/runtime versions in local and CI environments.
• Keep formatting and linting automated to avoid noisy diffs in code review.
• Prefer explicit dependency lock files for reproducible builds.
• Write small, deterministic tests that can run quickly in pre-commit checks.
• Document compiler/interpreter flags used in production builds.

Related Sheets

• SQLite Cheat Sheet — daily SQLite commands and production-ready examples.
• Scala Cheat Sheet — daily Scala commands and production-ready examples.
• YAML Cheat Sheet — daily YAML commands and production-ready examples.