Error on multiple ids parameters instead of warning

sanitiser/_ids.js

@@ -18,11 +18,13 @@ function sanitize( raw, clean ){
 
   // 'raw.ids' can be an array if ids is specified multiple times
   // see https://github.com/pelias/api/issues/272
-  var rawIdsString;
   if (check.array( raw.ids )) {
-    rawIdsString = raw.ids[0];
-    messages.warnings.push( '`ids` parameter specified multiple times. Using first value.' );
-  } else if (check.unemptyString( raw.ids )) {
+    messages.errors.push( '`ids` parameter specified multiple times.' );
+    return messages;
+  }
+
+  var rawIdsString;
+  if (check.unemptyString( raw.ids )) {
     rawIdsString = raw.ids;
   } else {
     rawIdsString = '';

test/unit/sanitiser/place.js

@@ -113,8 +113,8 @@ module.exports.tests.array_of_ids = function(test, common) {
   test('array of ids sent by queryparser', function(t) {
     var req = { query: { ids: ['geoname:2', 'oswmay:4'] } };
     sanitize(req, function() {
-      t.deepEqual( req.warnings, ['`ids` parameter specified multiple times. Using first value.'], 'warning sent' );
-      t.deepEqual( req.clean.ids, [{ id: '2', type: 'geoname' }], 'only first value used in clean' );
+      t.deepEqual( req.errors, ['`ids` parameter specified multiple times.'], 'error sent' );
+      t.deepEqual( req.clean.ids, undefined, 'response is empty due to error' );
       t.end();
     });
   });