Merge pull request #241 from nmote/html

Add HTML comments

grammar.js

@@ -951,7 +951,18 @@ module.exports = grammar({
         '/*',
         /[^*]*\*+([^/*][^*]*\*+)*/,
         '/'
-      )
+      ),
+      // https://tc39.es/ecma262/#sec-html-like-comments
+      seq('<!--', /.*/),
+      // This allows code to exist before this token on the same line.
+      //
+      // Technically, --> is supposed to have nothing before it on the same line
+      // except for comments and whitespace, but that is difficult to express,
+      // and in general tree sitter grammars tend to prefer to be overly
+      // permissive anyway.
+      //
+      // This approach does not appear to cause problems in practice.
+      seq('-->', /.*/)
     )),
 
     template_string: $ => seq(

src/grammar.json

@@ -4960,6 +4960,32 @@
                 "value": "/"
               }
             ]
+          },
+          {
+            "type": "SEQ",
+            "members": [
+              {
+                "type": "STRING",
+                "value": "<!--"
+              },
+              {
+                "type": "PATTERN",
+                "value": ".*"
+              }
+            ]
+          },
+          {
+            "type": "SEQ",
+            "members": [
+              {
+                "type": "STRING",
+                "value": "-->"
+              },
+              {
+                "type": "PATTERN",
+                "value": ".*"
+              }
+            ]
           }
         ]
       }

test/corpus/statements.txt

@@ -648,6 +648,40 @@ y // comment
 (program (expression_statement
   (binary_expression (identifier) (comment) (identifier))))
 
+==========================================
+HTML Comments
+==========================================
+
+<!-- we can put whatever we like here. this affects one line only.
+y * z;
+<!-- and here as well. these do not have to have matching close comments.
+
+x + 1; --> for some reason you can put text after a close comment.
+
+--> note that the x + 1 above should be rejected according to the spec.
+--> it should instead be rejected as invalid.
+--> you are supposed to only have whitespace or comments before
+--> an HTML close comment.
+
+---
+
+(program
+  (comment)
+  (expression_statement
+    (binary_expression
+      (identifier)
+      (identifier)))
+  (comment)
+  (expression_statement
+    (binary_expression
+      (identifier)
+      (number)))
+  (comment)
+  (comment)
+  (comment)
+  (comment)
+  (comment))
+
 ============================================
 Switch statements
 ============================================