Fix after_script processing for Runners APIv4

changelogs/unreleased/fix-ci-api-regression-for-after-script.yml

+---
+title: Fix after_script processing for Runners APIv4
+merge_request: 10185
+author:

lib/gitlab/ci/build/step.rb

@@ -7,13 +7,12 @@ module Gitlab
         WHEN_ALWAYS = 'always'.freeze
         attr_reader :name
-        attr_writer :script
-        attr_accessor :timeout, :when, :allow_failure
+        attr_accessor :script, :timeout, :when, :allow_failure
         class << self
           def from_commands(job)
             self.new(:script).tap do |step|
-              step.script = job.commands
+              step.script = job.commands.split("\n")
               step.timeout = job.timeout
               step.when = WHEN_ON_SUCCESS
             end
@@ -36,10 +35,6 @@ module Gitlab
           @name = name
           @allow_failure = false
         end
-
-        def script
-          @script.split("\n")
-        end
       end
     end
   end

spec/factories/ci/builds.rb

@@ -172,7 +172,7 @@ FactoryGirl.define do
         {
             image: 'ruby:2.1',
             services: ['postgres'],
-            after_script: "ls\ndate",
+            after_script: %w(ls date),
             artifacts: {
                 name: 'artifacts_file',
                 untracked: false,

spec/lib/gitlab/ci/build/step_spec.rb

@@ -25,7 +25,7 @@ describe Gitlab::Ci::Build::Step do
     end
     context 'when after_script is not empty' do
-      let(:job) { create(:ci_build, options: { after_script: "ls -la\ndate" }) }
+      let(:job) { create(:ci_build, options: { after_script: ['ls -la', 'date'] }) }
       it 'fabricates an object' do
         expect(subject.name).to eq(:after_script)