Rename pipeline expressions statement exception class

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

@@ -20,7 +20,7 @@ module Gitlab
           def tokenize
             MAX_CYCLES.times do
               LEXEMES.each do |lexeme|
-                @scanner.scan(/\s+/) # ignore whitespace
+                @scanner.skip(/\s+/) # ignore whitespace
 
                 lexeme.scan(@scanner).tap do |token|
                   @tokens.push(token) if token.present?

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

@@ -3,7 +3,7 @@ module Gitlab
     module Pipeline
       module Expression
         class Statement
-          ParserError = Class.new(StandardError)
+          StatementError = Class.new(StandardError)
 
           GRAMMAR = [
             %w[variable equals string],
@@ -37,10 +37,10 @@ module Gitlab
           # a reverse descent parse tree "by hand".
           #
           def parse_tree
-            raise ParserError if lexemes.empty?
+            raise StatementError if lexemes.empty?
 
             unless GRAMMAR.find { |syntax| syntax == lexemes }
-              raise ParserError, 'Unknown pipeline expression!'
+              raise StatementError, 'Unknown pipeline expression!'
             end
 
             if tokens.many?

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

@@ -25,10 +25,21 @@ describe Gitlab::Ci::Pipeline::Expression::Statement do
   end
 
   describe '#parse_tree' do
+    context 'when expression is empty' do
+      let(:text) { '' }
+
+      it 'raises an error' do
+        expect { subject.parse_tree }
+          .to raise_error described_class::StatementError
+      end
+    end
+
     context 'when expression grammar is incorrect' do
+      let(:text) { '$VAR "text"' }
+
       it 'raises an error' do
         expect { subject.parse_tree }
-          .to raise_error described_class::ParserError
+          .to raise_error described_class::StatementError
       end
     end