I've been curious about using Danger for a while, though I feel like I'm lacking a fair bit of background knowledge re: iOS/Swift build processes and CI to really be able to integrate the tool. It's not entirely clear to me that this works for an iOS / macOS app, or if it's just for Swift Packages, so that's why I created a single-view iOS app called DangerTest to test this out.
Followed the "Swift PM" version of the installation instructions. Had to create a file called Dummyfile.swift in my iOS project that only imports Foundation, and then created this Package.swift file based on the sample code in the docs:
// swift-tools-version:4.2
import PackageDescription
let package = Package(
name: "DangerTest",
dependencies: [
.package(url: "https://github.com/danger/swift.git", from: "1.0.0")
],
targets: [
// This is just an arbitrary Swift file in our app, that has
// no dependencies outside of Foundation, the dependencies section
// ensures that the library for Danger gets build also.
.target(name: "dangertest", dependencies: ["Danger"], path: "DangerTest", sources: ["Dummyfile.swift"]),
]
)Should I be using a newer version of swift-tools-version? Swift is at 5.2 but I don't know if swift-tools is versioned in lockstep. Not sure if "dangertest" is the right name for a target; at least in the iOS app project in Xcode, target names use uppercased words (e.g., DangerTest). Is this supposed to be the same target as my iOS app? Is this a different target that will be built later? I don't know.
% swift build seems to complete without issue. Moving on!
% [swift run] danger edit fails with:
zsh: bad pattern: [swiftI kinda figured the [] brackets would cause an error. I'm not sure why they're there. Is swift run optional? Is it supposed to be implied? I think this is dependent on whether I installed via SwiftPM or Brew.
% swift run danger edit fails with:
error: no executable product named 'danger'Interesting. Didn't I just install that? The installation section says I should be able to run swift run danger-swift [cmd], maybe that's a typo in the docs.
% swift run danger-swift edit seems to work because it runs a bunch of stuff in the terminal, then launches a new Xcode project called Dangerfile. I'm then told, "to get yourself started, add this to the Dangerfile.swift in the Xcode project"… but there is no Dangerfile.swift file in the project. There's a Package.swift, and there's Sources/Dangerfile/main.swift, but that's about it. Should I create new file? Looking through the linked document "About The Dangerfile", it looks like the format for my Dangerfile matches what's in Sources/Dangerfile/main.swift, so let's see what happens if I add the sample code here.
I save the changes to Sources/Dangerfile/main.swift and then see in the terminal that I just need to press the return key once I'm done, so I do that and I'm returned to the prompt. It looks like that worked, because I now have a Dangerfile.swift in the root directory that contains the sample code, so that's good!
I don't have an existing PR available since this is a brand new iOS project, but the instructions here are really helpful for this exact situation. Here goes:
% swift run danger-swift pr https://github.com/danger/swift/pull/146
ERROR: commandFailed(command: "which danger", exitCode: 1, stdout: "danger not found\n", stderr: "")Huh. Now what? Let's dig into the GitHub issues, where I find this open issue that suggests I need to have Danger JS installed before I can run commands, maybe — this leads me to this PR that updates the README to include installation steps for Danger JS. So let me try that and then run the above local test again.
% npm install -g danger completes without issue, so I try running the local test again, and it seems to work:
% swift run danger-swift pr https://github.com/danger/swift/pull/146
Starting Danger PR on danger/swift#146
You don't have a DANGER_GITHUB_API_TOKEN set up, this is optional, but TBH, you want to do this
Check out: http://danger.systems/js/guides/the_dangerfile.html#working-on-your-dangerfile
Danger: ✓ passed, found only messages.
## Messages
These files have changed: CHANGELOG.md, Sources/DangerFixtures/DangerFixtures.swift, Tests/DangerTests/XCTestManifests.swift, Sources/Danger/Plugins/SwiftLint/CurrentPathProvider.swift, Sources/Danger/Plugins/SwiftLint/ShellExecutor.swift, Sources/Danger/Plugins/SwiftLint/SwiftLint.swift, Sources/Danger/Plugins/SwiftLint/SwiftLintViolation.swift, Tests/DangerTests/SwiftLint/DangerSwiftLintTests.swift, Tests/DangerTests/SwiftLint/FakeCurrentPathProvider.swift, Tests/DangerTests/SwiftLint/FakeShellExecutor.swift, Tests/DangerTests/SwiftLint/URL+Utils.swift, Tests/DangerTests/SwiftLint/ViolationTests.swiftCool!
This is optional but recommended. Do I need to do this if I intend on using Danger Swift as a GitHub Action? I don't want to pay to add a bot account to my team if I don't have to, so I'm going to try skipping this for now and see what happens.
Following the instructions to use GitHub Actions here after skipping the creation of a bot account. I'll set it up as its own action, rather than making Danger as another build step. I don't really know what the pros and cons are of either, but right now it seems like the simplest solution. I replace the boilerplate YAML with what's in the docs:
name: "Danger Swift"
on: [pull_request]
jobs:
build:
name: Danger JS
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v1
- name: Danger
uses: danger/[email protected]
env: GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}Searching for "Danger Swift" in the GitHub Actions marketplace suggests I use this instead:
- name: Danger Swift
uses: danger/[email protected]So I replace those lines in the file and hit preview… and see a preview of the same file on GitHub, so that's not super helpful. Is it validating anything? Would I see an error if there was one?
According to the Danger Swift docs, "you can use the [auto-generated] GITHUB_TOKEN to authenticate in a workflow run. Using this token will post the danger comment as the github-actions app user." So that suggests I was right about being able to skip the creation of a bot account. I commit the GitHub Actions YAML file to the master branch and I'm ready for the next step.
I should be able to push some commits and have GitHub Actions do something — I guess I'll need to open a PR to trigger Danger. Let's see what happens!
I checkout a new branch with all the Danger stuff added in the local repo and add my changes — immediately getting a warning:
% git add .
warning: adding embedded git repository: .build/checkouts/Files
hint: You've added another git repository inside your current repository.
hint: Clones of the outer repository will not contain the contents of
hint: the embedded repository and will not know how to obtain it.
hint: If you meant to add a submodule, use:
hint:
hint: git submodule add <url> .build/checkouts/Files
hint:
hint: If you added this path by mistake, you can remove it from the
hint: index with:
hint:
hint: git rm --cached .build/checkouts/Files
hint:
hint: See "git help submodule" for more information.
warning: adding embedded git repository: .build/checkouts/Logger
warning: adding embedded git repository: .build/checkouts/Marathon
warning: adding embedded git repository: .build/checkouts/Releases
warning: adding embedded git repository: .build/checkouts/RequestKit
warning: adding embedded git repository: .build/checkouts/Require
warning: adding embedded git repository: .build/checkouts/ShellOut
warning: adding embedded git repository: .build/checkouts/octokit.swift
warning: adding embedded git repository: .build/checkouts/swiftTrying to follow the instructions fails:
% git rm --cached .build/checkouts/Files
error: the following file has staged content different from both the
file and the HEAD:
.build/checkouts/Files
(use -f to force removal)I guess I should have added .build to a .gitignore file or something. Oh well, this is just a test repo, so that's fine. Let's continue. I commit my changes and push them up to GitHub on a feature branch.
Once that's done, I open a PR on GitHub… and wait. Nothing seems to happen and so I go to the GitHub Actions tab and see that it did run a workflow when I committed the YAML file, but it failed:
Check failure on line 12 in .github/workflows/main.yml
GitHub Actions / .github/workflows/main.yml
Invalid workflow file You have an error in your yaml syntax on line 12
Okay. That's the env: line which, looking back, shouldn't have no value, and the GITHUB_TOKEN stuff should be on its own line. That's my fault, I think I missed the return key when adding that! I change it and go back to the GitHub Actions tab — and it still fails:
Check failure
GitHub Actions /.github/workflows/main.yml
Error No jobs defined in
jobs
Blerf?
Maybe it's a whitespace/indentation error. Looking in the GitHub issues for Danger Swift, I see this file, so I fix up my YAML file to use the same — this matches what I see in the README (which I haven't looked at, since I'm going through the guide on the site):
name: "Danger Swift"
on: [pull_request]
jobs:
build:
runs-on: ubuntu-latest
name: "Run Danger"
steps:
- uses: actions/checkout@v1
- name: Danger
uses: danger/[email protected]
with:
args: --failOnErrors --no-publish-check
env:
GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}Let's see if that sorts things out. I close my old PR and open a new one aaaaand… it looks like the action is running! Building Danger takes a while (4m30s) and then… fails. Okay, we're getting closer!
On the "Danger" step of the job, I have:
Error: { Error: write EPIPE
at afterWriteDispatched (internal/stream_base_commons.js:78:25)
at writeGeneric (internal/stream_base_commons.js:73:3)
at Socket._writeGeneric (net.js:714:5)
at Socket._write (net.js:726:8)
at doWrite (_stream_writable.js:415:12)
at writeOrBuffer (_stream_writable.js:399:5)
at Socket.Writable.write (_stream_writable.js:299:11)
at sendDSLToSubprocess (/github/home/.npm/_npx/1/lib/node_modules/danger/distribution/commands/utils/runDangerSubprocess.js:89:25)
at Object.exports.runDangerSubprocess (/github/home/.npm/_npx/1/lib/node_modules/danger/distribution/commands/utils/runDangerSubprocess.js:100:5)
at Object.<anonymous> (/github/home/.npm/_npx/1/lib/node_modules/danger/distribution/commands/ci/runner.js:112:39) errno: 'EPIPE', code: 'EPIPE', syscall: 'write' }
I think this might be because there's no Dangerfile in the repo yet? I'll merge this in, make a trivial PR, and try again.
But, nope, that doesn't help. So now I'm stuck. Technically, I've added Danger to the repository, but it… doesn't work for some reason that I don't fully understand.
I looked for 'EPIPE' in various Danger repos on GitHub. This one suggested the problem is something to do with a dependency on Marathon. Not sure I can do too much about that?