1 files changed, 45 insertions, 3 deletions
diff --git a/spec/lib/gitlab/ci/pipeline/expression/parser_spec.rb b/spec/lib/gitlab/ci/pipeline/expression/parser_spec.rb
index 2b78b1dd4a7..e88ec5561b6 100644
--- a/spec/lib/gitlab/ci/pipeline/expression/parser_spec.rb
+++ b/spec/lib/gitlab/ci/pipeline/expression/parser_spec.rb
@@ -2,25 +2,67 @@ require 'fast_spec_helper'
 
 describe Gitlab::Ci::Pipeline::Expression::Parser do
   describe '#tree' do
-    context 'when using operators' do
+    context 'when using two operators' do
+      it 'returns a reverse descent parse tree' do
+        expect(described_class.seed('$VAR1 == "123"').tree)
+          .to be_a Gitlab::Ci::Pipeline::Expression::Lexeme::Equals
+      end
+    end
+
+    context 'when using three operators' do
       it 'returns a reverse descent parse tree' do
         expect(described_class.seed('$VAR1 == "123" == $VAR2').tree)
           .to be_a Gitlab::Ci::Pipeline::Expression::Lexeme::Equals
       end
     end
 
-    context 'when using a single token' do
+    context 'when using a single variable token' do
       it 'returns a single token instance' do
         expect(described_class.seed('$VAR').tree)
           .to be_a Gitlab::Ci::Pipeline::Expression::Lexeme::Variable
       end
     end
 
+    context 'when using a single string token' do
+      it 'returns a single token instance' do
+        expect(described_class.seed('"some value"').tree)
+          .to be_a Gitlab::Ci::Pipeline::Expression::Lexeme::String
+      end
+    end
+
     context 'when expression is empty' do
       it 'returns a null token' do
-        expect(described_class.seed('').tree)
+        expect { described_class.seed('').tree }
+          .to raise_error Gitlab::Ci::Pipeline::Expression::Parser::ParseError
+      end
+    end
+
+    context 'when expression is null' do
+      it 'returns a null token' do
+        expect(described_class.seed('null').tree)
           .to be_a Gitlab::Ci::Pipeline::Expression::Lexeme::Null
       end
     end
+
+    context 'when two value tokens have no operator' do
+      it 'raises a parsing error' do
+        expect { described_class.seed('$VAR "text"').tree }
+          .to raise_error Gitlab::Ci::Pipeline::Expression::Parser::ParseError
+      end
+    end
+
+    context 'when an operator has no left side' do
+      it 'raises an OperatorError' do
+        expect { described_class.seed('== "123"').tree }
+            .to raise_error Gitlab::Ci::Pipeline::Expression::Lexeme::Operator::OperatorError
+      end
+    end
+
+    context 'when an operator has no right side' do
+      it 'raises an OperatorError' do
+        expect { described_class.seed('$VAR ==').tree }
+            .to raise_error Gitlab::Ci::Pipeline::Expression::Lexeme::Operator::OperatorError
+      end
+    end
   end
 end