Allow overrides of some GitHub defined variables

action.yml

@@ -11,11 +11,19 @@ inputs:
   GL_RUNNER_TOKEN:
     description: 'A runner token, if a runner should be started in this action'
   GL_API_TOKEN:
-    description: 'A token to check the pipeline status with. Required if the project is private'
+    description: 'A token to check the pipeline status with'
     required: true
   SHOW_JOB_LOGS:
     description: 'Set if the job log should be shown in the action output'
     default: 'none'
+
+  # Overrides of default variables
+  OVERRIDE_GITHUB_SHA:
+    description: 'Override the git sha given from GitHub'
+  OVERRIDE_GITHUB_REF:
+    description: 'Override the git ref given from GitHub. Should be in format "refs/<type>/<name>"'
+  OVERRIDE_GITHUB_REF_NAME:
+    description: 'Override the git ref name given from GitHub'
 author: 'Taucher2003'
 runs:
   using: 'docker'

lib/action/helper/env.rb

@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+module GitlabPipelineAction
+  module Helper
+    module Env
+      module_function
+
+      def fetch(*args, default: nil, allow_blank: false)
+        args.each do |key|
+          value = ENV.fetch(key, nil)
+
+          return value if !value.nil? && (!value.strip.empty? || allow_blank)
+        end
+
+        default
+      end
+    end
+  end
+end

lib/action/step/base.rb

@@ -18,6 +18,10 @@ def skip?
       def github
         GitlabPipelineAction::Helper::Github
       end
+
+      def env
+        GitlabPipelineAction::Helper::Env
+      end
     end
   end
 end

lib/action/step/prepare_context.rb

@@ -4,25 +4,25 @@ module GitlabPipelineAction
   module Step
     class PrepareContext < Base
       def execute
-        context.gh_project = ENV.fetch('GITHUB_REPOSITORY', nil)
-        context.gh_sha = ENV.fetch('GITHUB_SHA', nil)
-        context.gh_ref = ENV.fetch('GITHUB_REF', nil)
-        context.gh_server_url = ENV.fetch('GITHUB_SERVER_URL', nil)
+        context.gh_project = env.fetch('GITHUB_REPOSITORY')
+        context.gh_sha = env.fetch('INPUT_OVERRIDE_GITHUB_SHA', 'GITHUB_SHA')
+        context.gh_ref = env.fetch('INPUT_OVERRIDE_GITHUB_REF', 'GITHUB_REF')
+        context.gh_server_url = env.fetch('GITHUB_SERVER_URL')
 
-        context.gl_branch_name = "glpa/#{ENV.fetch('GITHUB_REF_NAME', nil)}"
+        context.gl_branch_name = "glpa/#{env.fetch('INPUT_OVERRIDE_GITHUB_REF_NAME', 'GITHUB_REF_NAME')}"
 
-        context.gl_server_url = ENV.fetch('INPUT_GL_SERVER_URL', nil)
-        context.gl_server_url_for_runner = ENV.fetch(
+        context.gl_server_url = env.fetch('INPUT_GL_SERVER_URL')
+        context.gl_server_url_for_runner = env.fetch(
           'INPUT_GL_SERVER_URL_FOR_RUNNER', # intentionally undocumented
-          context.gl_server_url
+          default: context.gl_server_url
         )
-        context.gl_project_id = ENV.fetch('INPUT_GL_PROJECT_ID', nil)
-        context.gl_runner_token = ENV.fetch('INPUT_GL_RUNNER_TOKEN', nil)
-        context.gl_api_token = ENV.fetch('INPUT_GL_API_TOKEN', nil)
+        context.gl_project_id = env.fetch('INPUT_GL_PROJECT_ID')
+        context.gl_runner_token = env.fetch('INPUT_GL_RUNNER_TOKEN')
+        context.gl_api_token = env.fetch('INPUT_GL_API_TOKEN')
         context.gl_pipeline_variables = ENV.select { |key| key.start_with?('GLPA_') }
                                            .transform_keys { |key| key.delete_prefix('GLPA_') }
 
-        context.gl_show_job_logs = ENV.fetch('INPUT_SHOW_JOB_LOGS', nil)&.to_sym
+        context.gl_show_job_logs = env.fetch('INPUT_SHOW_JOB_LOGS')&.to_sym
 
         context.git_path = "/tmp/repo/#{SecureRandom.hex}"
 

lib/gitlab_pipeline_action.rb

@@ -5,6 +5,7 @@
 require 'securerandom'
 require 'docker'
 
+require 'action/helper/env'
 require 'action/helper/github'
 
 require 'action/step/base'

spec/action/helper/env_spec.rb

@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe GitlabPipelineAction::Helper::Env do
+  stub_env('TEST_A', 'value_a')
+  stub_env('TEST_B', 'value_b')
+  stub_env('TEST_C', 'value_c')
+  stub_env('TEST_D', '')
+
+  context 'when used with a single argument' do
+    it 'returns the env value' do
+      expect(described_class.fetch('TEST_A')).to eq('value_a')
+    end
+
+    it 'returns the env value if default is given' do
+      expect(described_class.fetch('TEST_A', default: 'value_default')).to eq('value_a')
+    end
+
+    it 'returns nil if env var does not exist' do
+      expect(described_class.fetch('BLUB')).to be_nil
+    end
+
+    it 'returns default if env var does not exist' do
+      expect(described_class.fetch('BLUB', default: 'value_default')).to eq('value_default')
+    end
+
+    it 'returns the default if only a blank value exists' do
+      expect(described_class.fetch('TEST_D', default: 'value_default')).to eq('value_default')
+    end
+
+    it 'returns the blank value if allow_blank is set' do
+      expect(described_class.fetch('TEST_D', default: 'value_default', allow_blank: true)).to eq('')
+    end
+  end
+
+  context 'when used with multiple arguments' do
+    it 'returns the first env var' do
+      expect(described_class.fetch('TEST_A', 'TEST_B', 'TEST_C')).to eq('value_a')
+    end
+
+    it 'returns the first env var that exists' do
+      expect(described_class.fetch('BLUB', 'TEST_B', 'TEST_C')).to eq('value_b')
+    end
+
+    it 'returns the first env var that exists when default is given' do
+      expect(described_class.fetch('BLUB', 'TEST_B', 'TEST_C', default: 'value_default')).to eq('value_b')
+    end
+
+    it 'returns nil if no env var exists' do
+      expect(described_class.fetch('BLUB', 'BLAB', 'BLUB_BLAB')).to be_nil
+    end
+
+    it 'returns default if no env var exists' do
+      expect(described_class.fetch('BLUB', 'BLAB', 'BLUB_BLAB', default: 'value_default')).to eq('value_default')
+    end
+  end
+end

spec/action/step/prepare_context_spec.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe GitlabPipelineAction::Step::PrepareContext do
+  let(:context) { GitlabPipelineAction::Context.new }
+  let(:step) { described_class.new(context) }
+
+  before do
+    step.execute
+  end
+
+  it 'takes data from default variables', :aggregate_failures do
+    expect(context.gh_sha).to eq('master')
+    expect(context.gh_ref).to eq('refs/heads/master')
+    expect(context.gl_branch_name).to eq('glpa/master')
+  end
+
+  context 'when ref variables are overridden' do
+    stub_env('INPUT_OVERRIDE_GITHUB_SHA', '123')
+    stub_env('INPUT_OVERRIDE_GITHUB_REF', 'refs/heads/blub')
+    stub_env('INPUT_OVERRIDE_GITHUB_REF_NAME', 'blub')
+
+    it 'takes data from the override', :aggregate_failures do
+      expect(context.gh_sha).to eq('123')
+      expect(context.gh_ref).to eq('refs/heads/blub')
+      expect(context.gl_branch_name).to eq('glpa/blub')
+    end
+  end
+end