1 files changed, 25 insertions, 0 deletions
diff --git a/lib/gitlab/ci/pipeline/expression/lexeme/variable.rb b/lib/gitlab/ci/pipeline/expression/lexeme/variable.rb
new file mode 100644
index 00000000000..b781c15fd67
--- /dev/null
+++ b/lib/gitlab/ci/pipeline/expression/lexeme/variable.rb
@@ -0,0 +1,25 @@
+module Gitlab
+  module Ci
+    module Pipeline
+      module Expression
+        module Lexeme
+          class Variable < Lexeme::Value
+            PATTERN = /\$(?<name>\w+)/.freeze
+
+            def initialize(name)
+              @name = name
+            end
+
+            def evaluate(variables = {})
+              HashWithIndifferentAccess.new(variables).fetch(@name, nil)
+            end
+
+            def self.build(string)
+              new(string.match(PATTERN)[:name])
+            end
+          end
+        end
+      end
+    end
+  end
+end