realm/swiftlint

SwiftLint is a command-line tool that automatically checks Swift source code for style problems and enforces coding conventions. A linter is a program that reads your code and flags issues, not bugs, but stylistic inconsistencies that make code harder to read and maintain, like lines that are too long, inconsistent naming, unnecessary forced unwrapping, or unused variables. SwiftLint helps teams keep their Swift code consistent without relying on manual code review to catch every formatting issue. It works by analyzing Swift files using SwiftSyntax (the official Swift compiler's parsing infrastructure) and, for some rules, also hooks into Clang and SourceKit to access type information. The tool integrates directly into Xcode so violations are highlighted in the editor as you code, or it can run as a build step so the build fails if rules are violated. You can configure which rules apply to your project through a configuration file, and it supports auto-correction for many rules, running SwiftLint with the fix flag will automatically reformat code to comply with the rules. Installation options include Homebrew (the most common), Swift Package Manager, CocoaPods, Mint, and Bazel. SwiftLint is used by any iOS, macOS, tvOS, or watchOS developer working in Swift who wants to maintain a consistent codebase, enforce team coding standards, or catch common style issues automatically during development or in a CI pipeline.