Add Dependencies to Gitlab::Backup::Cli

gems/gitlab-backup-cli/lib/gitlab/backup/cli.rb

@@ -7,6 +7,7 @@ module Cli
       autoload :VERSION, 'gitlab/backup/cli/version'
       autoload :Runner, 'gitlab/backup/cli/runner'
       autoload :Utils, 'gitlab/backup/cli/utils'
+      autoload :Dependencies, 'gitlab/backup/cli/dependencies'
 
       Error = Class.new(StandardError)
       # Your code goes here...

gems/gitlab-backup-cli/lib/gitlab/backup/cli/dependencies.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Backup
+    module Cli
+      module Dependencies
+        # Search on PATH or default locations for provided binary and return its fullpath
+        #
+        # @param [String] binary name
+        # @return [String|False] full path to the binary file
+        def self.find_executable(binary)
+          executable_file = proc { |name| next name if File.file?(name) && File.executable?(name) }
+
+          # Retrieve PATH from ENV or use a fallback
+          path = ENV['PATH']&.split(File::PATH_SEPARATOR) || %w[/usr/local/bin /usr/bin /bin]
+
+          # check binary against each PATH
+          path.each do |dir|
+            file = File.expand_path(binary, dir)
+
+            return file if executable_file.call(file)
+          end
+
+          nil
+        end
+
+        # Check whether provided binary name exists on PATH or default locations
+        #
+        # @param [String] binary name
+        # @return [Boolean] whether binary exists
+        def self.executable_exist?(name)
+          !!find_executable(name)
+        end
+      end
+    end
+  end
+end

gems/gitlab-backup-cli/spec/gitlab/backup/cli/dependencies_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Backup::Cli::Dependencies do
+  let(:bin_path) { Dir.mktmpdir('dependencies', temp_path) }
+
+  before do
+    stub_env('PATH', bin_path)
+  end
+
+  after do
+    FileUtils.rmtree(bin_path)
+  end
+
+  describe '.find_executable' do
+    it 'returns the full path of the executable' do
+      executable = create_dummy_executable('dummy')
+
+      expect(described_class.find_executable('dummy')).to eq(executable)
+    end
+
+    it 'returns nil when executable cant be found' do
+      expect(described_class.find_executable('non-existent')).to be_nil
+    end
+
+    it 'also finds by absolute path' do
+      executable = create_dummy_executable('dummy')
+
+      expect(described_class.find_executable(executable)).to eq(executable)
+    end
+  end
+
+  describe '.executable_exist?' do
+    it 'returns true if an executable exists in the PATH' do
+      create_dummy_executable('dummy')
+
+      expect(described_class.executable_exist?('dummy')).to be_truthy
+    end
+
+    it 'returns false when no exectuable can be found' do
+      expect(described_class.executable_exist?('non-existent')).to be_falsey
+    end
+  end
+
+  def create_dummy_executable(name)
+    filepath = File.join(bin_path, name)
+
+    FileUtils.touch(filepath)
+    File.chmod(0o755, filepath)
+
+    filepath
+  end
+end

gems/gitlab-backup-cli/spec/gitlab/backup/cli_spec.rb

 # frozen_string_literal: true
 
+require 'spec_helper'
+
 RSpec.describe Gitlab::Backup::Cli do
   it "has a version number" do
     expect(Gitlab::Backup::Cli::VERSION).not_to be nil

gems/gitlab-backup-cli/spec/spec_helper.rb

 # frozen_string_literal: true
 
 require "gitlab/backup/cli"
+require 'tmpdir'
+require 'fileutils'
+
+# Load spec support code
+Dir['spec/support/**/*.rb'].each { |f| load f }
 
 RSpec.configure do |config|
   # Enable flags like --only-failures and --next-failure

gems/gitlab-backup-cli/spec/support/helpers.rb

+# frozen_string_literal: true
+
+def spec_path
+  Pathname.new(__dir__).join('..').expand_path
+end
+
+def temp_path
+  spec_path.join('..', 'tmp').expand_path
+end
+
+def stub_env(var, return_value)
+  stub_const('ENV', ENV.to_hash.merge(var => return_value))
+end