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Write your Dangerfiles in Swift 4+.


Latest version requires Swift 4.1.

If you are using Swift 4.0, Use v0.3.5 .

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("CHANGELOG.md")
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.")

CI Configuration

In your CI:

# Setup
npm install -g danger                 # Get DangerJS
brew install danger/tap/danger-swift  # Install danger-swift locally

# Script
danger process danger-swift           # Run Danger

Local installation


brew install danger/tap/danger-swift

Manual install

git clone https://github.com/danger/danger-swift.git
cd danger-swift
make install

What are the next big steps?


Setting up:

  1. Install Danger Swift: brew install danger/tap/danger-swift.
  2. Edit the dangerfile: danger-swift edit.

This will make a Dangerfile.swift for you., then pop up a temporary Xcode project set up for editing a Swift Dangerfile.


Infrastructure exists to support plugins, which can help you avoid repeating the same Danger rules across separate repos. By suffixing package: [url] to an import, you can directly import Swift PM package as a dependency(through Marathon), which is basically how plugins work.

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

// Dangerfile.swift

import DangerPlugin // package: https://github.com/username/DangerPlugin.git


And could be implemented with the following.

// DangerPlugin.swift
import Danger

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

How it works

This project takes its ideas from how the Swift Package Manager handles package manifests. You can get the long story here, but the TLDR is that there is a runner project which compiles and executes a runtime lib which exports its data out into JSON when the libs process is over.

So this project will export a lib libDanger and a CLI tool danger-swift which is the runner. danger-swift handles turning the Danger DSL JSON message from DangerJS and passing that into the eval'd Dangerfile.swift. When that process is finished it's expected that the Swift Danger object would post the results into a place where they can easily be passed back to DangerJS.


You need to be using Xcode 9.

git clone https://github.com/danger/danger-swift.git
cd danger-swift
swift build
swift package generate-xcodeproj
open Danger.xcodeproj

Then I tend to run it by eval the Dangerfile with:

swift build && swiftc --driver-mode=swift -L .build/debug -I .build/debug -lDanger Dangerfile.swift fixtures/eidolon_609.json fixtures/response_data.json

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


  1. Update the CHANGELOG entry
  2. Edit the Makefile and Sources/Danger/Danger.swift with the version
  3. Commit the changes
  4. Create a git tag for the version
  5. Wait a second, run make get_sha to grab the SHA
  6. Edit the brew formula with the new SHA/version
  7. Announce


I, orta, only plan on bootstrapping this project, as I won't be using this in production. I'm happy to help support others who want to own this idea and really make it shine though! So if you're interested in helping out, make a few PRs and I'll give you org access.