need to allow empty strings when a string property has a format

src/lib.rs

@@ -157,7 +157,11 @@ fn validate_json_schema(schema_id: &str, instance: JsonB) -> JsonB {
           let errors = format_errors(error_list, &instance_value, schema_id);
           // Filter out FALSE_SCHEMA errors if there are other validation errors
           let filtered_errors = filter_false_schema_errors(errors);
-          JsonB(json!({ "errors": filtered_errors }))
+          if filtered_errors.is_empty() {
+            JsonB(json!({ "response": "success" }))
+          } else {
+            JsonB(json!({ "errors": filtered_errors }))
+          }
         }
       }
     }
@@ -486,6 +490,13 @@ fn handle_additional_items_error(base_path: &str, got: usize) -> Vec<Error> {
 }
 
 fn handle_format_error(base_path: &str, want: &str, got: &Cow<Value>, err: &Box<dyn std::error::Error>) -> Vec<Error> {
+  // If the value is an empty string, skip format validation.
+  if let Value::String(s) = got.as_ref() {
+    if s.is_empty() {
+      return vec![];
+    }
+  }
+
   vec![Error {
     path: base_path.to_string(),
     code: "FORMAT_INVALID".to_string(),

src/tests.rs

@@ -1237,3 +1237,53 @@ fn test_unevaluated_properties_errors() {
   let valid_result = validate_json_schema(schema_id, jsonb(valid_instance));
   assert_success_with_json!(valid_result, "All properties are evaluated, should pass");
 }
+
+#[pg_test]
+fn test_format_validation_allows_empty_string() {
+  clear_json_schemas();
+  let schema_id = "format_schema_empty";
+  let schema = json!({
+    "type": "object",
+    "properties": {
+      "uuid": { "type": "string", "format": "uuid" },
+      "date_time": { "type": "string", "format": "date-time" },
+      "email": { "type": "string", "format": "email" }
+    }
+  });
+  
+  let _ = cache_json_schema(schema_id, jsonb(schema), false);
+  
+  // Test with empty strings for all formatted fields
+  let instance = json!({
+    "uuid": "",
+    "date_time": "",
+    "email": ""
+  });
+  
+  let result = validate_json_schema(schema_id, jsonb(instance));
+  
+  // This is the test that should fail before the change and pass after
+  assert_success_with_json!(result, "Empty strings should be allowed for format validation");
+}
+
+#[pg_test]
+fn test_non_empty_string_format_validation_still_fails() {
+  clear_json_schemas();
+  let schema_id = "non_empty_fail_schema";
+  let schema = json!({
+    "type": "object",
+    "properties": {
+      "date_time": { "type": "string", "format": "date-time" }
+    }
+  });
+  
+  let _ = cache_json_schema(schema_id, jsonb(schema), false);
+  
+  // A non-empty but invalid string should still fail
+  let instance = json!({
+    "date_time": "not-a-date"
+  });
+  
+  let result = validate_json_schema(schema_id, jsonb(instance));
+  assert_failure_with_json!(result, 1, "Value \"not-a-date\" is not a valid date-time format");
+}