Merge branch 'fix/ci-linter-undefined-error' into 'master'

Fix undefined error in CI linter

## What does this MR do?

This MR fixes undefined error in CI linter.

## Does this MR meet the acceptance criteria?

- [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- [x] Tests added for this feature/bug
  
## What are the relevant issue numbers?

Closes #24759

See merge request !7650

changelogs/unreleased/fix-ci-linter-undefined-error.yml

+---
+title: Fix undefined error in CI linter
+merge_request: 7650
+author: 

lib/gitlab/ci/config/entry/job.rb

@@ -108,7 +108,7 @@ module Gitlab
 
             self.class.nodes.each_key do |key|
               global_entry = deps[key]
-              job_entry = @entries[key]
+              job_entry = self[key]
 
               if global_entry.specified? && !job_entry.specified?
                 @entries[key] = global_entry

spec/lib/gitlab/ci/config/entry/global_spec.rb

@@ -13,7 +13,7 @@ describe Gitlab::Ci::Config::Entry::Global do
     end
   end
 
-  context 'when hash is valid' do
+  context 'when configuration is valid' do
     context 'when some entries defined' do
       let(:hash) do
         { before_script: ['ls', 'pwd'],
@@ -225,9 +225,10 @@ describe Gitlab::Ci::Config::Entry::Global do
     end
   end
 
-  context 'when hash is not valid' do
+  context 'when configuration is not valid' do
     before { global.compose! }
 
+    context 'when before script is not an array' do
       let(:hash) do
         { before_script: 'ls' }
       end
@@ -252,6 +253,20 @@ describe Gitlab::Ci::Config::Entry::Global do
       end
     end
 
+    context 'when job does not have commands' do
+      let(:hash) do
+        { before_script: ['echo 123'], rspec: { stage: 'test' } }
+      end
+
+      describe '#errors' do
+        it 'reports errors about missing script' do
+          expect(global.errors)
+            .to include "jobs:rspec script can't be blank"
+        end
+      end
+    end
+  end
+
   context 'when value is not a hash' do
     let(:hash) { [] }
 
@@ -281,7 +296,7 @@ describe Gitlab::Ci::Config::Entry::Global do
       { cache: { key: 'a' }, rspec: { script: 'ls' } }
     end
 
-    context 'when node exists' do
+    context 'when entry exists' do
       it 'returns correct entry' do
         expect(global[:cache])
           .to be_an_instance_of Gitlab::Ci::Config::Entry::Cache
@@ -289,7 +304,7 @@ describe Gitlab::Ci::Config::Entry::Global do
       end
     end
 
-    context 'when node does not exist' do
+    context 'when entry does not exist' do
       it 'always return unspecified node' do
         expect(global[:some][:unknown][:node])
           .not_to be_specified