Add default env_file

Author: iangmaia

lib/fastlane/plugin/wpmreleasetoolkit/actions/common/buildkite_upload_pipeline_action.rb

@@ -1,6 +1,9 @@
 module Fastlane
   module Actions
     class BuildkiteUploadPipelineAction < Action
+      DEFAULT_ENV_FILE = File.join('.buildkite', 'shared-pipeline-vars').freeze
+      DEFAULT_COMMIT = 'HEAD'.freeze
+
       def self.run(params)
         env_file = params[:env_file]
         pipeline_file = params[:pipeline_file]
@@ -44,6 +47,7 @@ def self.available_options
             key: :env_file,
             description: 'The path to a bash file to be sourced before uploading the pipeline',
             optional: true,
+            default_value: DEFAULT_ENV_FILE,
             type: String
           ),
           FastlaneCore::ConfigItem.new(
@@ -56,7 +60,7 @@ def self.available_options
             key: :commit,
             description: 'The commit hash you want to run the pipeline on',
             optional: true,
-            default_value: 'HEAD',
+            default_value: DEFAULT_COMMIT,
             type: String
           ),
         ]

spec/buildkite_upload_pipeline_action_spec.rb

@@ -4,7 +4,7 @@
   let(:pipeline_file) { 'path/to/pipeline.yml' }
   let(:branch) { 'feature-branch' }
   let(:commit) { 'abc123' }
-  let(:commit_default) { 'HEAD' }
+  let(:commit_default) { Fastlane::Actions::BuildkiteUploadPipelineAction::DEFAULT_COMMIT }
 
   before do
     allow(File).to receive(:exist?).with(anything)