Support empty comment lines in runtime parser (#149)

Author: zbraniecki

fluent-syntax/test/fixtures_structure/multiline-comment.ftl

@@ -0,0 +1,6 @@
+
+# This is
+#
+# An example of a multiline comment
+
+key = Value

fluent-syntax/test/fixtures_structure/multiline-comment.json

@@ -0,0 +1,59 @@
+{
+  "type": "Resource",
+  "body": [
+    {
+      "type": "Comment",
+      "annotations": [],
+      "content": "This is\n\nAn example of a multiline comment",
+      "span": {
+        "type": "Span",
+        "start": 1,
+        "end": 48
+      }
+    },
+    {
+      "type": "Message",
+      "annotations": [],
+      "id": {
+        "type": "Identifier",
+        "name": "key",
+        "span": {
+          "type": "Span",
+          "start": 50,
+          "end": 53
+        }
+      },
+      "value": {
+        "type": "Pattern",
+        "elements": [
+          {
+            "type": "TextElement",
+            "value": "Value",
+            "span": {
+              "type": "Span",
+              "start": 56,
+              "end": 61
+            }
+          }
+        ],
+        "span": {
+          "type": "Span",
+          "start": 56,
+          "end": 61
+        }
+      },
+      "attributes": [],
+      "comment": null,
+      "span": {
+        "type": "Span",
+        "start": 50,
+        "end": 61
+      }
+    }
+  ],
+  "span": {
+    "type": "Span",
+    "start": 0,
+    "end": 62
+  }
+}

fluent/src/parser.js

@@ -75,7 +75,8 @@ class RuntimeParser {
 
     // We don't care about comments or sections at runtime
     if (ch === '/' ||
-      (ch === '#' && [' ', '#'].includes(this._source[this._index + 1]))) {
+      (ch === '#' &&
+        [' ', '#', '\n'].includes(this._source[this._index + 1]))) {
       this.skipComment();
       return;
     }

fluent/test/fixtures_structure/multiline-comment.json

@@ -0,0 +1,3 @@
+{
+  "key": "Value"
+}