Merge pull request #15425 from redlizard/expr-boolean-literal

fix: Support $expr clauses with a boolean literal as an expression

Author: vkarpov15

lib/helpers/query/cast$expr.js

@@ -69,8 +69,11 @@ const dateOperators = new Set([
 const expressionOperator = new Set(['$not']);
 
 module.exports = function cast$expr(val, schema, strictQuery) {
+  if (typeof val === 'boolean') {
+    return val;
+  }
   if (typeof val !== 'object' || val === null) {
-    throw new Error('`$expr` must be an object');
+    throw new Error('`$expr` must be an object or boolean literal');
   }
 
   return _castExpression(val, schema, strictQuery);