Support Cypher multi-line comments (#1710)

* resolves #1709 support Cypher multi-line comments

* Remove empty line

* Add newline at the end of the file

lib/rouge/lexers/cypher.rb

@@ -45,6 +45,7 @@ def self.keywords
       state :root do
         rule %r/[\s]+/, Text
         rule %r(//.*?$), Comment::Single
+        rule %r(/\*), Comment::Multiline, :multiline_comments
 
         rule %r([*+\-<>=&|~%^]), Operator
         rule %r/[{}),;\[\]]/, Str::Symbol
@@ -103,6 +104,13 @@ def self.keywords
         rule %r/'(\\\\|\\'|[^'])*'/, Str::Single
         rule %r/`(\\\\|\\`|[^`])*`/, Str::Backtick
       end
+
+      state :multiline_comments do
+        rule %r(/[*]), Comment::Multiline, :multiline_comments
+        rule %r([*]/), Comment::Multiline, :pop!
+        rule %r([^/*]+), Comment::Multiline
+        rule %r([/*]), Comment::Multiline
+      end
     end
   end
 end

spec/lexers/cypher_spec.rb

@@ -15,4 +15,24 @@
       assert_guess :mimetype => 'application/x-cypher-query'
     end
   end
+
+  describe 'lexing' do
+    include Support::Lexing
+
+    describe 'comments' do
+      describe 'inline comment' do
+        it 'handles inline comment' do
+          assert_tokens_includes "RETURN point({longitude: 2.2105491 /* x */, latitude: 48.9250016 /* y */, srid: 4326}) AS home",
+                                 ["Comment.Multiline", "/* x */"],
+                                 ["Comment.Multiline", "/* y */"]
+        end
+
+        it 'handles multiline comment' do
+          assert_tokens_includes "RETURN /* drum\nrolls */ 42",
+                                 ["Comment.Multiline", "/* drum\nrolls */"],
+                                 ["Literal.Number.Integer", "42"]
+        end
+      end
+    end
+  end
 end

spec/support/lexing.rb

@@ -43,5 +43,16 @@ def assert_tokens_equal(text, *expected)
       actual = lexer.lex(text).map { |token, value| [ token.qualname, value ] }
       assert { expected == actual }
     end
+
+    def assert_tokens_includes(text, *expected)
+      if expected.first.is_a? Rouge::Lexer
+        lexer = expected.shift
+      else
+        lexer = subject
+      end
+
+      actual = lexer.lex(text).map { |token, value| [ token.qualname, value ] }
+      expected.all? { |e| assert_includes actual, e  }
+    end
   end
 end

spec/visual/samples/cypher

@@ -100,3 +100,5 @@ MATCH (p:Person)-[rel]->(:Movie {title:'The Matrix'})
 RETURN p.name, type(rel)
 
 RETURN sign(-17), sign(0.1), sign(0xABCDEF), sign(000)
+
+RETURN point({longitude: 2.2105491 /* x */, latitude: 48.9250016 /* y */, srid: 4326}) AS home