Build-time checks

One invalid class leaves a whole surface undecorated at run time. swiftcn-lint finds those classes when you build, with the swiftcn parser itself. Xcode shows each problem as an error on the line that contains it:

PlayerView.swift:9:44: error: Unknown swiftcn class 'text-muted-foregrund'. Did you mean 'text-muted-foreground'?

Check every buildCopy Anchor Link

The installation steps add the build plugin. It runs before the target's Swift sources compile, so an invalid class fails the build first. To add it to another target:

.target(
    name: "App",
    dependencies: [.product(name: "SwiftCN", package: "swiftcn")],
    plugins: [.plugin(name: "SwiftCNLintPlugin", package: "swiftcn")]
)

In an Xcode project, open the target's Build Phases, expand Run Build Tool Plug-ins, and add SwiftCNLintPlugin. Xcode asks you to trust the plugin the first time it runs. The check runs again only when a Swift file in the target changes.

Check without buildingCopy Anchor Link

Run the command plugin from your package directory:

swift package swiftcn-lint
swift package swiftcn-lint --target App --format json

Or run the tool on any files or directories:

swift run swiftcn-lint Sources

It exits with status 1 when it finds an invalid class. --format json prints each problem with its file, line, column, the class, and a suggested replacement. Coding agents can run it after each edit and apply the suggestion, then build.

What it checksCopy Anchor Link

The tool checks class strings in .tw("…"), .buttonStyle(.tw("…")) and the other control styles, .twAnimation("…"), cn(…), classes: arguments, and TWClasses or TWStyle literals. It also checks the classes inside recipes that you register with named:. Each class goes through TWStyle.parse, so the rules match the runtime exactly.

Interpolated values inside brackets stay typed Swift, so the tool checks only the variants and the prefix: rotate-[\(angle)]. A runtime string outside brackets, such as "\(base) p-4", can hold any classes; the tool checks the literal classes around it. Typed utilities such as .tw(.p(4), .bg(.surface)) are already checked by the compiler.

Custom classesCopy Anchor Link

The tool learns the names that your sources register: recipes in named, custom classes in modifiers and utilities, presets in animations, and colors declared with TWColor("brand"). List names registered in another module in swiftcn-lint.json, next to the target's sources or at the package root:

{
  "classes": ["brand-chip"],
  "prefixes": ["tilt"],
  "animations": ["wobble"],
  "colors": ["brand"],
  "warningsOnly": false
}

Set warningsOnly to report problems as warnings while you adopt the check. Suppress one line with a comment:

Text("Draft").tw("p-4 experimental-glow") // swiftcn-lint: ignore

Use // swiftcn-lint: ignore-next-line on the line before.

Class referenceCopy Anchor Link

classes.md lists every class that the parser accepts, generated from the parser's own tables. Point coding agents at it, or at llms.txt, so they write valid classes on the first try.