Improve extended CI/CD config specs and fix a bug

2 files changed, 6 insertions, 5 deletions

diff --git a/lib/gitlab/ci/config/extendable/collection.rb b/lib/gitlab/ci/config/extendable/collection.rb
index b57b3aa5d47..123219c90f2 100644
--- a/lib/gitlab/ci/config/extendable/collection.rb
+++ b/lib/gitlab/ci/config/extendable/collection.rb
@@ -10,7 +10,7 @@ module Gitlab
           CircularDependencyError = Class.new(ExtensionError)
 
           def initialize(hash)
-            @hash = hash.deep_dup
+            @hash = hash.to_h.deep_dup
 
             each { |entry| entry.extend! if entry.extensible? }
           end
diff --git a/lib/gitlab/ci/config/extendable/entry.rb b/lib/gitlab/ci/config/extendable/entry.rb
index 5b26faaa806..f14d2c1817c 100644
--- a/lib/gitlab/ci/config/extendable/entry.rb
+++ b/lib/gitlab/ci/config/extendable/entry.rb
@@ -40,16 +40,17 @@ module Gitlab
 
             if unknown_extension?
               raise Extendable::Collection::InvalidExtensionError,
-                    'Unknown extension!'
+                    "Unknown extends key in extended `#{key}`!"
             end
 
             if invalid_base?
               raise Extendable::Collection::InvalidExtensionError,
-                    'Invalid base hash!'
+                    "Invalid base hash in extended `#{key}`!"
             end
 
             if circular_dependency?
-              raise Extendable::Collection::CircularDependencyError
+              raise Extendable::Collection::CircularDependencyError,
+                    "Circular dependency detected in extended `#{key}`!"
             end
 
             @context[key] = base_hash!.deep_merge(value)
@@ -62,7 +63,7 @@ module Gitlab
           end
 
           def unknown_extension?
-            !@context.key?(key)
+            !@context.key?(extends_key)
           end
 
           def invalid_base?