From e2be5e58b56ad029559986fa7aed2a516e6b2e89 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Hru=C5=A1ka?= <ondra@ondrovo.com>
Date: Tue, 14 Jul 2020 15:00:22 +0200
Subject: [PATCH] Add cJSON_AddObjectToArray() helper fn & unit tests

---
 cJSON.c           | 13 +++++++++++++
 cJSON.h           |  4 ++++
 tests/cjson_add.c | 34 ++++++++++++++++++++++++++++++++++
 3 files changed, 51 insertions(+)

diff --git a/cJSON.c b/cJSON.c
index 3cdc8fa..29e5dbf 100644
--- a/cJSON.c
+++ b/cJSON.c
@@ -1995,6 +1995,19 @@ CJSON_PUBLIC(cJSON_bool) cJSON_AddItemToArray(cJSON *array, cJSON *item)
     return add_item_to_array(array, item);
 }
 
+/** Create object and add it to array */
+CJSON_PUBLIC(cJSON*) cJSON_AddObjectToArray(cJSON * const array)
+{
+    cJSON *object = cJSON_CreateObject();
+    if (cJSON_AddItemToArray(array, object))
+    {
+        return object;
+    }
+
+    cJSON_Delete(object);
+    return NULL;
+}
+
 #if defined(__clang__) || (defined(__GNUC__)  && ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ > 5))))
     #pragma GCC diagnostic push
 #endif
diff --git a/cJSON.h b/cJSON.h
index b5ceb29..1fbcca8 100644
--- a/cJSON.h
+++ b/cJSON.h
@@ -271,6 +271,10 @@ CJSON_PUBLIC(cJSON*) cJSON_AddRawToObject(cJSON * const object, const char * con
 CJSON_PUBLIC(cJSON*) cJSON_AddObjectToObject(cJSON * const object, const char * const name);
 CJSON_PUBLIC(cJSON*) cJSON_AddArrayToObject(cJSON * const object, const char * const name);
 
+/* Helper function to create an object and add it to an existing array.
+ * It returns the added object or NULL on failure. */
+CJSON_PUBLIC(cJSON*) cJSON_AddObjectToArray(cJSON * const array);
+
 /* When assigning an integer value, it needs to be propagated to valuedouble too. */
 #define cJSON_SetIntValue(object, number) ((object) ? (object)->valueint = (object)->valuedouble = (number) : (number))
 /* helper for the cJSON_SetNumberValue macro */
diff --git a/tests/cjson_add.c b/tests/cjson_add.c
index 00ffc34..7cb69fa 100644
--- a/tests/cjson_add.c
+++ b/tests/cjson_add.c
@@ -378,6 +378,36 @@ static void cjson_add_array_should_fail_on_allocation_failure(void)
     cJSON_Delete(root);
 }
 
+static void cJSON_add_object_to_array_should_add_object(void)
+{
+    cJSON *root = cJSON_CreateArray();
+    cJSON *object = NULL;
+
+    TEST_ASSERT_NOT_NULL(object = cJSON_AddObjectToArray(root));
+    TEST_ASSERT_EQUAL_INT(cJSON_GetArraySize(root), 1);
+    TEST_ASSERT_EQUAL_INT(cJSON_GetArrayItem(root, 0)->type, cJSON_Object);
+
+    cJSON_Delete(root);
+}
+
+static void cjson_add_object_to_array_should_fail_with_null_pointers(void)
+{
+    TEST_ASSERT_NULL(cJSON_AddObjectToArray(NULL));
+}
+
+static void cjson_add_object_to_array_should_fail_on_allocation_failure(void)
+{
+    cJSON *root = cJSON_CreateArray();
+
+    cJSON_InitHooks(&failing_hooks);
+
+    TEST_ASSERT_NULL(cJSON_AddObjectToArray(root));
+
+    cJSON_InitHooks(NULL);
+
+    cJSON_Delete(root);
+}
+
 int CJSON_CDECL main(void)
 {
     UNITY_BEGIN();
@@ -418,5 +448,9 @@ int CJSON_CDECL main(void)
     RUN_TEST(cjson_add_array_should_fail_with_null_pointers);
     RUN_TEST(cjson_add_array_should_fail_on_allocation_failure);
 
+    RUN_TEST(cJSON_add_object_to_array_should_add_object);
+    RUN_TEST(cjson_add_object_to_array_should_fail_with_null_pointers);
+    RUN_TEST(cjson_add_object_to_array_should_fail_on_allocation_failure);
+
     return UNITY_END();
 }