fix(schema): correctly handle trailing array filters when looking up …

…schema paths

Fix #9977

lib/helpers/schema/cleanPositionalOperators.js

@@ -7,6 +7,6 @@
 
 module.exports = function cleanPositionalOperators(path) {
   return path.
-    replace(/\.\$(\[[^\]]*\])?\./g, '.0.').
-    replace(/\.(\[[^\]]*\])?\$$/g, '.0');
+    replace(/\.\$(\[[^\]]*\])?(?=\.)/g, '.0').
+    replace(/\.\$(\[[^\]]*\])?$/g, '.0');
 };

test/helpers/schema.cleanPositionalOperators.test.js

@@ -0,0 +1,22 @@
+'use strict';
+
+const assert = require('assert');
+const cleanPositionalOperators = require('../../lib/helpers/schema/cleanPositionalOperators');
+
+describe('cleanPositionalOperators', function() {
+  it('replaces trailing array filter', function() {
+    assert.equal(cleanPositionalOperators('questions.$[q]'), 'questions.0');
+  });
+
+  it('replaces trailing $', function() {
+    assert.equal(cleanPositionalOperators('questions.$'), 'questions.0');
+  });
+
+  it('replaces interior array filters', function() {
+    assert.equal(cleanPositionalOperators('questions.$[q].$[r].test'), 'questions.0.0.test');
+  });
+
+  it('replaces interior elemMatch', function() {
+    assert.equal(cleanPositionalOperators('questions.$.$.test'), 'questions.0.0.test');
+  });
+});