Do not remove empty default values for string and array respectively (#…

…1028)

* Do not remove empty string and empty array as default values for string and array respectively
* Save flag initial value for field was eliminated by optimization
* Add test case
* Mark test as correct

Signed-off-by: dsolomennikov <dsolomennikov@>

compiler/data/kphp-json-tags.cpp

@@ -403,7 +403,7 @@ FieldJsonSettings merge_and_inherit_json_tags(const ClassMemberInstanceField &fi
 
   // for 'public int $id;' — no default and non-nullable type — set 'required' so that decode() would fire unless exists
   // it could be overridden with `@kphp-json required = false`
-  if (field.type_hint && !field.var->init_val && !does_type_hint_allow_null(field.type_hint)) {
+  if (field.type_hint && !field.var->init_val && !field.var->had_user_assigned_val && !does_type_hint_allow_null(field.type_hint)) {
     s.required = true;
   }
 

compiler/data/var-data.h

@@ -32,6 +32,7 @@ class VarData {
   std::string name;
   tinf::VarNode tinf_node;
   VertexPtr init_val;
+  bool had_user_assigned_val = false;
   FunctionPtr holder_func;
   ClassPtr class_id;
   std::unordered_set<VarPtr> *bad_vars = nullptr;

compiler/pipes/optimization.cpp

@@ -358,6 +358,7 @@ void OptimizationPass::on_finish() {
 
         if (can_init_value_be_removed(class_field.var->init_val, class_field.var)) {
           class_field.var->init_val = {};
+          class_field.var->had_user_assigned_val = true;
         } else {
           explicit_cast_array_type(class_field.var->init_val, tinf::get_type(class_field.var));
         }

tests/phpt/json/38_optimized_init_val.php

@@ -0,0 +1,23 @@
+@ok
+<?php
+
+class User {
+  public string $name = '';
+  public string $password = '';
+}
+
+function test_optimized_init_value(): void {
+  $raw = '{"name": "user"}';
+
+  $user = JsonEncoder::decode($raw, User::class);
+
+  $error = JsonEncoder::getLastError();
+  if (!empty($error)) {
+    echo "Error: " . $error;
+    exit();
+  }
+
+  var_dump(instance_to_array($user));
+}
+
+test_optimized_init_value();