Add variables to pipeline expressions evaluator

lib/gitlab/ci/pipeline/expression/statement.rb

@@ -17,7 +17,10 @@ module Gitlab
           def initialize(statement, pipeline)
             @pipeline = pipeline
             @lexer = Expression::Lexer.new(statement)
-            @variables = pipeline.variables # TODO
+
+            @variables = pipeline.variables.map do |variable|
+              { variable.key => variable.value }
+            end
           end
 
           def tokens

spec/lib/gitlab/ci/pipeline/expression/statement_spec.rb

@@ -8,6 +8,10 @@ describe Gitlab::Ci::Pipeline::Expression::Statement do
     described_class.new(text, pipeline)
   end
 
+  before do
+    pipeline.variables.build([key: 'VARIABLE', value: 'my variable'])
+  end
+
   describe '#tokens' do
     it 'returns raw tokens' do
       expect(subject.tokens.size).to eq 2