Skip to content
/ swift Public

⚠️ Stop saying "you forgot to …" in code review


Notifications You must be signed in to change notification settings


Repository files navigation

Formalize your Pull Request etiquette.

Write your Dangerfiles in Swift.


Latest version requires Swift 5.5

If you are using an older Swift, use the supported version according to next table.

Swift version Danger support version
5.4 v3.15.0
5.3 v3.13.0
5.2 v3.11.1
5.1 v3.8.0
4.2 v2.0.7
4.1 v0.4.1
4.0 v0.3.6

What it looks like today

You can make a Dangerfile that looks through PR metadata, it's fully typed.

import Danger

let danger = Danger()
let allSourceFiles = danger.git.modifiedFiles + danger.git.createdFiles

let changelogChanged = allSourceFiles.contains("")
let sourceChanges = allSourceFiles.first(where: { $0.hasPrefix("Sources") })

if !changelogChanged && sourceChanges != nil {
  warn("No CHANGELOG entry added.")

// You can use these functions to send feedback:
message("Highlight something in the table")
warn("Something pretty bad, but not important enough to fail the build")
fail("Something that must be changed")

markdown("Free-form markdown that goes under the table, so you can do whatever.")

Using Danger Swift

All of the docs are on the user-facing website:


  • danger-swift ci - Use this on CI
  • danger-swift pr - Use this to build your Dangerfile
  • danger-swift local - Use this to run danger against your local changes from master
  • danger-swift edit - Creates a temporary Xcode project for working on a Dangerfile


Infrastructure exists to support plugins, which can help you avoid repeating the same Danger rules across separate repos.

e.g. A plugin implemented with the following at

// DangerPlugin.swift
import Danger

public struct DangerPlugin {
    let danger = Danger()
    public static func doYourThing() {
        // Code goes here

Swift Package Manager (More performant)

You can use Swift PM to install both danger-swift and your plugins:

  • Install Danger JS

    $ npm install -g danger
  • Add to your Package.swift:

    let package = Package(
        products: [
            .library(name: "DangerDeps[Product name (optional)]", type: .dynamic, targets: ["DangerDependencies"]), // dev
        dependencies: [
            .package(url: "", from: "3.0.0"), // dev
            // Danger Plugins
            .package(url: "", from: "0.1.0") // dev
        targets: [
            .target(name: "DangerDependencies", dependencies: ["Danger", "DangerPlugin"]), // dev
  • Add the correct import to your Dangerfile.swift:

    import DangerPlugin
  • Create a folder called DangerDependencies in Sources with an empty file inside like Fake.swift

  • To run Danger use swift run danger-swift command

  • (Recommended) If you are using Swift PM to distribute your framework, use Rocket, or a similar tool, to comment out all the dev dependencies from your Package.swift. This prevents these dev dependencies from being downloaded and compiled with your framework by consumers.

  • (Recommended) cache the .build folder on your repo

Marathon (Easy to use)

By suffixing package: [url] to an import, you can directly import Swift PM package as a dependency

For example, a plugin could be used by the following.

// Dangerfile.swift

import DangerPlugin // package:


You can see an example danger-swift plugin.

(Recommended) Cache the ~/.danger-swift folder


For a Mac:

# Install danger-swift, and a bundled danger-js locally
brew install danger/tap/danger-swift
 # Run danger
danger-swift ci

For Linux:

# Install danger-swift
git clone
cd danger-swift
make install

# Install danger-js
npm install -g danger

 # Run danger
danger-swift ci

GitHub Actions

You can add danger/swift to your actions

    runs-on: ubuntu-latest
    name: "Run Danger"
      - uses: actions/checkout@v1
      - name: Danger
        uses: danger/swift@3.15.0
            args: --failOnErrors --no-publish-check
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

Danger has two different pre built images that you can use with your action:

In order to import one of those use the docker:// prefix

    runs-on: ubuntu-latest
    name: "Run Danger"
      - uses: actions/checkout@v1
      - name: Danger
        uses: docker://
            args: --failOnErrors --no-publish-check
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

Local compiled danger-js

To use a local compiled copy of danger-js use the danger-js-path argument:

danger-swift command --danger-js-path path/to/danger-js

Current working directory

Many people prefer using Danger within a Swift Package via SPM, because is more performant.

When doing so, however, having a Package.swift in the root folder can be annoying, especially now that Xcode (since Xcode 11) doesn't show a xcproj (or xcworkspace) on the Open Recents menu when there is a Package.swift in the same folder.

With the --cwd parameter you can specify a working directory. This allows you to have your Package.swift in another directory and still run danger-swift as it was executed from your project root directory.

swift run danger-swift command --cwd path/to/working-directory

Note that to do this, you must run danger-swift from the directory where the Package.swift is located, and pass the top-level directory relative to this directory to the --cwd command-line switch. For example, if you create a folder named Danger in the top level of your repo for these files, you would need to cd Danger and then run the command [swift run] danger-swift cmd <cmd parameters> --cwd .. to tell Danger that it should look at the directory above where the command was executed to correctly invoke the tool.


You need to be using Xcode >= 13.2.1.

git clone
cd danger-swift
swift build
swift run komondor install
swift package generate-xcodeproj
open danger-swift.xcodeproj

Then I tend to run danger-swift using swift run:

swift run danger-swift pr

If you want to emulate how DangerJS's process will work entirely, then use:

swift build && cat Fixtures/eidolon_609.json | ./.build/debug/danger-swift


Run swift run rocket $VERSION on master e.g. swift run rocket 1.0.0


Danger Swift is maintained by @f-meloni, and maybe you?