Using Slather w/ Fastlane

Question

I am trying to use Slather w/ Fastlane.

My project Gem file

source "https://rubygems.org"

gem "fastlane"
gem "slather"

My Fastfile

platform :ios do
  desc "Run unit tests"
  lane :tests do
    scan(workspace: "Home.xcworkspace", device: "iPhone 6s", scheme: "Home", code_coverage: true)
  
  slather(
      output_directory: "fastlane/html",
      workspace: "Home.xcworkspace",
      html: true,
      scheme: "Home",
      proj: "Home.xcodeproj",
      ignore: [ "R.generated.swift", "Pods/*"],
      verbose: true,
      show: true
  )
  end
end

When running however it fails after running my tests with the following message

Missing gem 'slather', please add the following to your local Gemfile:

Add 'gem "slather"' to your Gemfile and restart fastlane

If I run gem install slather I get

Successfully installed slather-2.4.7
Parsing documentation for slather-2.4.7
Done installing documentation for slather after 0 seconds
1 gem installed

Answer 1

You have to use bundle exec fastlane ..., in your case bundle exec fastlane tests, for the Gemfile to take effect. (Make sure you have run bundle update for the Gemfile's dependencies to actually be installed)