Require valid plural & selectordinal keys

Author: eemeli

parser.pegjs

@@ -15,6 +15,10 @@ token
       };
     }
   / '{' _ arg:id _ ',' _ type:('plural'/'selectordinal') _ ',' _ offset:offset? cases:pluralCase+ _ '}' {
+      var ls = ((type === 'selectordinal') ? options.ordinal : options.cardinal);
+      if (ls && ls.length) cases.forEach(function(c) {
+        if (isNaN(c.key) && ls.indexOf(c.key) < 0) throw new Error('Invalid ' + type + ' key: ' + c.key);
+      });
       return {
         type: type,
         arg: arg,
@@ -43,7 +47,9 @@ caseTokens = '{' (_ & '{')? tokens:token* _ '}' { return tokens; }
 
 offset = _ 'offset' _ ':' _ d:digits _ { return d; }
 
-pluralKey = id / '=' d:digits { return d; }
+pluralKey
+  = $('zero'/'one'/'two'/'few'/'many'/'other')
+  / '=' d:digits { return d; }
 
 functionParams = _ ',' _ p:id _ { return p; }