Apply & drop LOCALIZATION NOTEs from comments

lib/build-fluent-message.js

@@ -15,10 +15,20 @@ import kebabCase from 'lodash.kebabcase'
  * @param {import('dot-properties').Node[]} props
  */
 export function buildFluentMessage(msgName, props, propNames) {
-  let comments = []
-  const getComment = () => {
-    const content = comments.join('\n').trim()
-    comments = []
+  let commentLines = []
+  const commentNotes = {}
+  const getComment = (key) => {
+    let content = commentLines.join('\n').trim()
+    commentLines = []
+    const ln = content.match(/^LOCALIZATION NOTE\s*(\([^)]*\))?:?\s*(.*)/)
+    if (ln) {
+      content = ln[2]
+      for (const tgt of ln[1].slice(1, -1).split(/[,\s]+/))
+        if (tgt && tgt !== key) commentNotes[tgt] = content
+    } else {
+      const cn = commentNotes[key]
+      if (cn) content = content ? cn + '\n' + content : cn
+    }
     return content ? new Comment(content) : null
   }
 
@@ -31,12 +41,12 @@ export function buildFluentMessage(msgName, props, propNames) {
 
       case 'COMMENT': {
         const line = node.comment.replace(/^[!#]\s*/, '')
-        if (!line.startsWith('-*-')) comments.push(line) // ignore mode lines
+        if (!line.startsWith('-*-')) commentLines.push(line) // ignore mode lines
         break
       }
 
       case 'PAIR': {
-        const comment = getComment()
+        const comment = getComment(node.key)
         const pattern = parseMsgPattern(node.value, propNames)
 
         const dot = node.key.indexOf('.')