Add language definition for R

syntax.json

@@ -611,5 +611,14 @@
         "pattern": "#"
       }
     ]
+  },
+  {
+    "language": "R",
+    "markers": [
+      {
+        "type": "line",
+        "pattern": "#"
+      }
+    ]
   }
 ]

tests/test_closed.diff

@@ -246,3 +246,16 @@ index 525e25d..ba4e68d 100644
 -   kept together as one todo
 - */}
 - - [ ] TODO: An inline todo that's NOT a comment (what)
+diff --git a/tests/example_file.r b/tests/example_file.r
+index 525e25d..ba4e68d 100644
+--- a/tests/example_file.r
++++ b/tests/example_file.r
+@@ -1,23 +1,2 @@
+hello_world <- function() {
+-    # TODO: Come up with a more imaginative greeting
+     message("Hello world")
+-
+-    # TODO: Do more stuff
+-    #  This function should probably do something more interesting
+-    #  labels: help wanted
+}

tests/test_new.diff

@@ -258,3 +258,17 @@ index 0000000..7cccc5b
 +   kept together as one todo
 + */}
 + - [ ] TODO: An inline todo that's NOT a comment (what)
+diff --git a/tests/example_file.r b/tests/example_file.r
+new file mode 100644
+index 0000000..525e25d
+--- /dev/null
++++ b/tests/example_file.r
+@@ -0,0 +1,23 @@
++hello_world <- function() {
++    # TODO: Come up with a more imaginative greeting
++    message("Hello world")
++
++    # TODO: Do more stuff
++    #  This function should probably do something more interesting
++    #  labels: help wanted
++}

tests/test_todo_parser.py

@@ -66,6 +66,9 @@ def test_twig_issues(self):
 
     def test_md_issues(self):
         self.assertEqual(count_issues_for_file_type(self.raw_issues, 'markdown'), 6)
+
+    def test_r_issues(self):
+        self.assertEqual(count_issues_for_file_type(self.raw_issues, 'r'), 2)
 
 
 class ClosedIssueTests(unittest.TestCase):
@@ -123,6 +126,8 @@ def test_twig_issues(self):
     def test_md_issues(self):
         self.assertEqual(count_issues_for_file_type(self.raw_issues, 'markdown'), 6)
 
+    def test_r_issues(self):
+        self.assertEqual(count_issues_for_file_type(self.raw_issues, 'r'), 2)
 
 class IgnorePatternTests(unittest.TestCase):