Build a recursive parser for pipeline expressions

1 files changed, 17 insertions, 0 deletions

diff --git a/spec/lib/gitlab/ci/pipeline/expression/parser_spec.rb b/spec/lib/gitlab/ci/pipeline/expression/parser_spec.rb
index 180b6908fb5..c70bcc8438c 100644
--- a/spec/lib/gitlab/ci/pipeline/expression/parser_spec.rb
+++ b/spec/lib/gitlab/ci/pipeline/expression/parser_spec.rb
@@ -2,5 +2,22 @@ require 'spec_helper'
 
 describe Gitlab::Ci::Pipeline::Expression::Parser do
   describe '#tree' do
+    context 'when using an operator' do
+      it 'returns a reverse descent parse tree' do
+        expect(described_class.new(tokens('$VAR == "123"')).tree)
+          .to be_a Gitlab::Ci::Pipeline::Expression::Equals
+      end
+    end
+
+    context 'when using a single token' do
+      it 'returns a single token instance' do
+        expect(described_class.new(tokens('$VAR')).tree)
+          .to be_a Gitlab::Ci::Pipeline::Expression::Variable
+      end
+    end
+  end
+
+  def tokens(statement)
+    Gitlab::Ci::Pipeline::Expression::Lexer.new(statement).tokens.to_enum
   end
 end