Fix span.start for Messages/Terms with Comments, fixes #255

Move the message.span.start logic from the wrapper to the point
where the comment is hooked up to the message.
As the message already has the span when it gets there, the
wrapper refuses to do it again.

Author: Pike

fluent-syntax/src/parser.js

@@ -14,7 +14,7 @@ function withSpan(fn) {
       return fn.call(this, ps, ...args);
     }
 
-    let start = ps.getIndex();
+    const start = ps.getIndex();
     const node = fn.call(this, ps, ...args);
 
     // Don't re-add the span if the node already has it.  This may happen when
@@ -23,13 +23,6 @@ function withSpan(fn) {
       return node;
     }
 
-    // Spans of Messages should include the attached Comment.
-    if (node.type === "Message") {
-      if (node.comment !== null) {
-        start = node.comment.span.start;
-      }
-    }
-
     const end = ps.getIndex();
     node.addSpan(start, end);
     return node;
@@ -80,6 +73,9 @@ export default class FluentParser {
       if (lastComment) {
         if (entry.type === "Message" || entry.type === "Term") {
           entry.comment = lastComment;
+          if (this.withSpans) {
+            entry.span.start = entry.comment.span.start;
+          }
         } else {
           entries.push(lastComment);
         }

fluent-syntax/test/fixtures_structure/whitespace_leading.json

@@ -45,7 +45,7 @@
       },
       "span": {
         "type": "Span",
-        "start": 21,
+        "start": 0,
         "end": 46
       }
     },
@@ -93,7 +93,7 @@
       },
       "span": {
         "type": "Span",
-        "start": 65,
+        "start": 48,
         "end": 84
       }
     },

fluent-syntax/test/fixtures_structure/whitespace_trailing.json

@@ -45,7 +45,7 @@
       },
       "span": {
         "type": "Span",
-        "start": 27,
+        "start": 0,
         "end": 53
       }
     },
@@ -93,7 +93,7 @@
       },
       "span": {
         "type": "Span",
-        "start": 77,
+        "start": 55,
         "end": 96
       }
     },