Using SwiftLint to generate code quality report for Gitlab

Gitlab allows you to easily measure and report code quality of your merge requests to see your linting or other code issues right in every merge request you make in a nice and concise way.

I have been using SwiftLint for a very long time now in my iOS projects so I decided to integrate it to the Gitlab code quality flow.

This is quite easy because SwifLint can generate a Code Climate format that Gitlab understands. No need for any custom format conversion or data transformation.

To set it up in Gitlab you need to modify your .gitlab-ci.yml file. First include the code quality template

include:
  - template: Code-Quality.gitlab-ci.yml

and then add a new job called code_quality, it needs to have this exact name to match the included template

code_quality:
  dependencies: []
  stage: linting
  artifacts:
    paths:
      - codequality_report.json
    reports:
      codequality: codequality_report.json
  script:
    - swiftlint --reporter codeclimate > codequality_report.json 
  tags:
    - iOS-arm

This works for a simple project. In my projects I usually use an iOS application project and a few smaller framework projects that the iOS application uses, so instead of swiftlint --reporter codeclimate > codequality_report.json I call a custom shell script

#!/bin/bash

for target in sources/**/.swiftlint.yml
do
    name=($(basename "$(dirname "$target")"))
    path="sources/$name"
    
    echo $path
    cd $path
    swiftlint --reporter codeclimate > codequality_report.json

    pattern="\"path\" : \""
    replacement="\"path\" : \"sources\/$name\/"
    sed -i'' -e "s/$pattern/$replacement/g" codequality_report.json
    cd -
done

jq -s '[.[][]]' sources/**/codequality_report.json > codequality_report.json

This script finds all the projects in the sources folder that contain a SwiftLint rule definition, generates a code climate report for each them and then merges those reports into one single report.