Ignore interleaved comments in the Parser

Author: leocassarani

lib/parser.rb

@@ -1,16 +1,24 @@
 class Parser
-  attr_reader :lines
-
   def initialize(input)
-    input = input.gsub(%r{//.*$}, '').strip
-    @lines = input.lines
+    @lines = split_lines(input)
   end
 
   def has_more_commands?
-    !@lines.empty?
+    !lines.empty?
   end
 
   def advance
-    @lines.shift
+    lines.shift
+  end
+
+  private
+
+  attr_reader :lines
+
+  def split_lines(input)
+    input
+      .lines
+      .map { |line| line.sub(%r{//.*$}, '').strip }
+      .reject(&:empty?)
   end
 end

spec/unit/parser_spec.rb

@@ -102,6 +102,24 @@
         expect(parser.has_more_commands?).to be_falsy
       end
     end
+
+    context 'with interleaved comments' do
+      let(:input) do
+        <<-eop
+          @R0
+          // An interleaved comment
+          D=M
+        eop
+      end
+
+      it 'leaves no more commands' do
+        expect(parser.has_more_commands?).to be_truthy
+        parser.advance
+        expect(parser.has_more_commands?).to be_truthy
+        parser.advance
+        expect(parser.has_more_commands?).to be_falsy
+      end
+    end
   end
 
   describe '#command_type' do