Merge pull request #148 from DaveGamble/cjson-compare

cJSON_Compare

cJSON.c

@@ -70,23 +70,17 @@ CJSON_PUBLIC(const char*) cJSON_Version(void)
     return version;
 }
 
-/* case insensitive strcmp */
-static int cJSON_strcasecmp(const unsigned char *string1, const unsigned char *string2)
+/* Case insensitive string comparison, doesn't consider two NULL pointers equal though */
+static int case_insensitive_strcmp(const unsigned char *string1, const unsigned char *string2)
 {
-    if (string1 == NULL)
+    if ((string1 == NULL) || (string2 == NULL))
     {
-        if (string2 == NULL)
-        {
-            /* both NULL */
-            return 0;
-        }
-
         return 1;
     }
 
-    if (string2 == NULL)
+    if (string1 == string2)
     {
-        return 1;
+        return 0;
     }
 
     for(; tolower(*string1) == tolower(*string2); (void)string1++, string2++)
@@ -97,7 +91,7 @@ static int cJSON_strcasecmp(const unsigned char *string1, const unsigned char *s
         }
     }
 
-    return tolower(string1[0]) - tolower(string2[0]);
+    return tolower(*string1) - tolower(*string2);
 }
 
 typedef struct internal_hooks
@@ -1683,34 +1677,44 @@ CJSON_PUBLIC(cJSON *) cJSON_GetArrayItem(const cJSON *array, int item)
     return c;
 }
 
-CJSON_PUBLIC(cJSON *) cJSON_GetObjectItem(const cJSON *object, const char *string)
-{
-    cJSON *c = object ? object->child : NULL;
-    while (c && cJSON_strcasecmp((unsigned char*)c->string, (const unsigned char*)string))
-    {
-        c = c->next;
-    }
-    return c;
-}
-
-CJSON_PUBLIC(cJSON *) cJSON_GetObjectItemCaseSensitive(const cJSON * const object, const char * const string)
+static cJSON *get_object_item(const cJSON * const object, const char * const name, const cJSON_bool case_sensitive)
 {
     cJSON *current_element = NULL;
 
-    if ((object == NULL) || (string == NULL))
+    if ((object == NULL) || (name == NULL))
     {
         return NULL;
     }
 
     current_element = object->child;
-    while ((current_element != NULL) && (strcmp(string, current_element->string) != 0))
+    if (case_sensitive)
     {
-        current_element = current_element->next;
+        while ((current_element != NULL) && (strcmp(name, current_element->string) != 0))
+        {
+            current_element = current_element->next;
+        }
+    }
+    else
+    {
+        while ((current_element != NULL) && (case_insensitive_strcmp((const unsigned char*)name, (const unsigned char*)(current_element->string)) != 0))
+        {
+            current_element = current_element->next;
+        }
     }
 
     return current_element;
 }
 
+CJSON_PUBLIC(cJSON *) cJSON_GetObjectItem(const cJSON *object, const char *string)
+{
+    return get_object_item(object, string, false);
+}
+
+CJSON_PUBLIC(cJSON *) cJSON_GetObjectItemCaseSensitive(const cJSON * const object, const char * const string)
+{
+    return get_object_item(object, string, true);
+}
+
 CJSON_PUBLIC(cJSON_bool) cJSON_HasObjectItem(const cJSON *object, const char *string)
 {
     return cJSON_GetObjectItem(object, string) ? 1 : 0;
@@ -1860,7 +1864,7 @@ CJSON_PUBLIC(cJSON *) cJSON_DetachItemFromObject(cJSON *object, const char *stri
 {
     size_t i = 0;
     cJSON *c = object->child;
-    while (c && cJSON_strcasecmp((unsigned char*)c->string, (const unsigned char*)string))
+    while (c && (case_insensitive_strcmp((unsigned char*)c->string, (const unsigned char*)string) != 0))
     {
         i++;
         c = c->next;
@@ -1948,7 +1952,7 @@ CJSON_PUBLIC(void) cJSON_ReplaceItemInObject(cJSON *object, const char *string,
 {
     size_t i = 0;
     cJSON *c = object->child;
-    while(c && cJSON_strcasecmp((unsigned char*)c->string, (const unsigned char*)string))
+    while(c && (case_insensitive_strcmp((unsigned char*)c->string, (const unsigned char*)string) != 0))
     {
         i++;
         c = c->next;
@@ -2480,3 +2484,104 @@ CJSON_PUBLIC(cJSON_bool) cJSON_IsRaw(const cJSON * const item)
 
     return (item->type & 0xFF) == cJSON_Raw;
 }
+
+CJSON_PUBLIC(cJSON_bool) cJSON_Compare(const cJSON * const a, const cJSON * const b, const cJSON_bool case_sensitive)
+{
+    if ((a == NULL) || (b == NULL) || ((a->type & 0xFF) != (b->type & 0xFF)) || cJSON_IsInvalid(a))
+    {
+        return false;
+    }
+
+    /* check if type is valid */
+    switch (a->type & 0xFF)
+    {
+        case cJSON_False:
+        case cJSON_True:
+        case cJSON_NULL:
+        case cJSON_Number:
+        case cJSON_String:
+        case cJSON_Raw:
+        case cJSON_Array:
+        case cJSON_Object:
+            break;
+
+        default:
+            return false;
+    }
+
+    /* identical objects are equal */
+    if (a == b)
+    {
+        return true;
+    }
+
+    switch (a->type & 0xFF)
+    {
+        /* in these cases and equal type is enough */
+        case cJSON_False:
+        case cJSON_True:
+        case cJSON_NULL:
+            return true;
+
+        case cJSON_Number:
+            if (a->valuedouble == b->valuedouble)
+            {
+                return true;
+            }
+            return false;
+
+        case cJSON_String:
+        case cJSON_Raw:
+            if ((a->valuestring == NULL) || (b->valuestring == NULL))
+            {
+                return false;
+            }
+            if (strcmp(a->valuestring, b->valuestring) == 0)
+            {
+                return true;
+            }
+
+            return false;
+
+        case cJSON_Array:
+        {
+            cJSON *a_element = NULL;
+            cJSON *b_element = NULL;
+            for (a_element = a->child, b_element = b->child;
+                    (a_element != NULL) && (b_element != NULL);
+                    a_element = a_element->next, b_element = b_element->next)
+            {
+                if (!cJSON_Compare(a_element, b_element, case_sensitive))
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        case cJSON_Object:
+        {
+            cJSON *a_element = NULL;
+            cJSON_ArrayForEach(a_element, a)
+            {
+                /* TODO This has O(n^2) runtime, which is horrible! */
+                cJSON *b_element = get_object_item(b, a_element->string, case_sensitive);
+                if (b_element == NULL)
+                {
+                    return false;
+                }
+
+                if (!cJSON_Compare(a_element, b_element, case_sensitive))
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        default:
+            return false;
+    }
+}

cJSON.h

@@ -212,6 +212,10 @@ CJSON_PUBLIC(cJSON *) cJSON_Duplicate(const cJSON *item, cJSON_bool recurse);
 /* Duplicate will create a new, identical cJSON item to the one you pass, in new memory that will
 need to be released. With recurse!=0, it will duplicate any children connected to the item.
 The item->next and ->prev pointers are always zero on return from Duplicate. */
+/* Recursively compare two cJSON items for equality. If either a or b is NULL or invalid, they will be considered unequal.
+ * case_sensitive determines if object keys are treated case sensitive (1) or case insensitive (0) */
+CJSON_PUBLIC(cJSON_bool) cJSON_Compare(const cJSON * const a, const cJSON * const b, const cJSON_bool case_sensitive);
+
 
 /* ParseWithOpts allows you to require (and check) that the JSON is null terminated, and to retrieve the pointer to the final byte parsed. */
 /* If you supply a ptr in return_parse_end and parsing fails, then return_parse_end will contain a pointer to the error. If not, then cJSON_GetErrorPtr() does the job. */

tests/CMakeLists.txt

@@ -46,6 +46,7 @@ if(ENABLE_CJSON_TEST)
         print_value
         misc_tests
         parse_with_opts
+        compare_tests
     )
 
     add_library(test-common common.c)

tests/compare_tests.c

@@ -0,0 +1,192 @@
+/*
+  Copyright (c) 2009-2017 Dave Gamble and cJSON contributors
+
+  Permission is hereby granted, free of charge, to any person obtaining a copy
+  of this software and associated documentation files (the "Software"), to deal
+  in the Software without restriction, including without limitation the rights
+  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+  copies of the Software, and to permit persons to whom the Software is
+  furnished to do so, subject to the following conditions:
+
+  The above copyright notice and this permission notice shall be included in
+  all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+  THE SOFTWARE.
+*/
+
+#include "unity/examples/unity_config.h"
+#include "unity/src/unity.h"
+#include "common.h"
+
+static cJSON_bool compare_from_string(const char * const a, const char * const b, const cJSON_bool case_sensitive)
+{
+    cJSON *a_json = NULL;
+    cJSON *b_json = NULL;
+    cJSON_bool result = false;
+
+    a_json = cJSON_Parse(a);
+    TEST_ASSERT_NOT_NULL_MESSAGE(a_json, "Failed to parse a.");
+    b_json = cJSON_Parse(b);
+    TEST_ASSERT_NOT_NULL_MESSAGE(b_json, "Failed to parse b.");
+
+    result = cJSON_Compare(a_json, b_json, case_sensitive);
+
+    cJSON_Delete(a_json);
+    cJSON_Delete(b_json);
+
+    return result;
+}
+
+static void cjson_compare_should_compare_null_pointer_as_not_equal(void)
+{
+    TEST_ASSERT_FALSE(cJSON_Compare(NULL, NULL, true));
+    TEST_ASSERT_FALSE(cJSON_Compare(NULL, NULL, false));
+}
+
+static void cjson_compare_should_compare_invalid_as_not_equal(void)
+{
+    cJSON invalid[1];
+    memset(invalid, '\0', sizeof(invalid));
+
+    TEST_ASSERT_FALSE(cJSON_Compare(invalid, invalid, false));
+    TEST_ASSERT_FALSE(cJSON_Compare(invalid, invalid, true));
+}
+
+static void cjson_compare_should_compare_numbers(void)
+{
+    TEST_ASSERT_TRUE(compare_from_string("1", "1", true));
+    TEST_ASSERT_TRUE(compare_from_string("1", "1", false));
+    TEST_ASSERT_TRUE(compare_from_string("0.0001", "0.0001", true));
+    TEST_ASSERT_TRUE(compare_from_string("0.0001", "0.0001", false));
+
+    TEST_ASSERT_FALSE(compare_from_string("1", "2", true));
+    TEST_ASSERT_FALSE(compare_from_string("1", "2", false));
+}
+
+static void cjson_compare_should_compare_booleans(void)
+{
+    /* true */
+    TEST_ASSERT_TRUE(compare_from_string("true", "true", true));
+    TEST_ASSERT_TRUE(compare_from_string("true", "true", false));
+
+    /* false */
+    TEST_ASSERT_TRUE(compare_from_string("false", "false", true));
+    TEST_ASSERT_TRUE(compare_from_string("false", "false", false));
+
+    /* mixed */
+    TEST_ASSERT_FALSE(compare_from_string("true", "false", true));
+    TEST_ASSERT_FALSE(compare_from_string("true", "false", false));
+    TEST_ASSERT_FALSE(compare_from_string("false", "true", true));
+    TEST_ASSERT_FALSE(compare_from_string("false", "true", false));
+}
+
+static void cjson_compare_should_compare_null(void)
+{
+    TEST_ASSERT_TRUE(compare_from_string("null", "null", true));
+    TEST_ASSERT_TRUE(compare_from_string("null", "null", false));
+
+    TEST_ASSERT_FALSE(compare_from_string("null", "true", true));
+    TEST_ASSERT_FALSE(compare_from_string("null", "true", false));
+}
+
+static void cjson_compare_should_not_accept_invalid_types(void)
+{
+    cJSON invalid[1];
+    memset(invalid, '\0', sizeof(invalid));
+
+    invalid->type = cJSON_Number | cJSON_String;
+
+    TEST_ASSERT_FALSE(cJSON_Compare(invalid, invalid, true));
+    TEST_ASSERT_FALSE(cJSON_Compare(invalid, invalid, false));
+}
+
+static void cjson_compare_should_compare_strings(void)
+{
+    TEST_ASSERT_TRUE(compare_from_string("\"abcdefg\"", "\"abcdefg\"", true));
+    TEST_ASSERT_TRUE(compare_from_string("\"abcdefg\"", "\"abcdefg\"", false));
+
+    TEST_ASSERT_FALSE(compare_from_string("\"ABCDEFG\"", "\"abcdefg\"", true));
+    TEST_ASSERT_FALSE(compare_from_string("\"ABCDEFG\"", "\"abcdefg\"", false));
+}
+
+static void cjson_compare_should_compare_raw(void)
+{
+    cJSON *raw1 = NULL;
+    cJSON *raw2 = NULL;
+
+    raw1 = cJSON_Parse("\"[true, false]\"");
+    TEST_ASSERT_NOT_NULL(raw1);
+    raw2 = cJSON_Parse("\"[true, false]\"");
+    TEST_ASSERT_NOT_NULL(raw2);
+
+    raw1->type = cJSON_Raw;
+    raw2->type = cJSON_Raw;
+
+    TEST_ASSERT_TRUE(cJSON_Compare(raw1, raw2, true));
+    TEST_ASSERT_TRUE(cJSON_Compare(raw1, raw2, false));
+
+    cJSON_Delete(raw1);
+    cJSON_Delete(raw2);
+}
+
+static void cjson_compare_should_compare_arrays(void)
+{
+    TEST_ASSERT_TRUE(compare_from_string("[]", "[]", true));
+    TEST_ASSERT_TRUE(compare_from_string("[]", "[]", false));
+
+    TEST_ASSERT_TRUE(compare_from_string("[false,true,null,42,\"string\",[],{}]", "[false, true, null, 42, \"string\", [], {}]", true));
+    TEST_ASSERT_TRUE(compare_from_string("[false,true,null,42,\"string\",[],{}]", "[false, true, null, 42, \"string\", [], {}]", false));
+
+    TEST_ASSERT_TRUE(compare_from_string("[[[1], 2]]", "[[[1], 2]]", true));
+    TEST_ASSERT_TRUE(compare_from_string("[[[1], 2]]", "[[[1], 2]]", false));
+
+    TEST_ASSERT_FALSE(compare_from_string("[true,null,42,\"string\",[],{}]", "[false, true, null, 42, \"string\", [], {}]", true));
+    TEST_ASSERT_FALSE(compare_from_string("[true,null,42,\"string\",[],{}]", "[false, true, null, 42, \"string\", [], {}]", false));
+}
+
+static void cjson_compare_should_compare_objects(void)
+{
+    TEST_ASSERT_TRUE(compare_from_string("{}", "{}", true));
+    TEST_ASSERT_TRUE(compare_from_string("{}", "{}", false));
+
+    TEST_ASSERT_TRUE(compare_from_string(
+                "{\"false\": false, \"true\": true, \"null\": null, \"number\": 42, \"string\": \"string\", \"array\": [], \"object\": {}}",
+                "{\"true\": true, \"false\": false, \"null\": null, \"number\": 42, \"string\": \"string\", \"array\": [], \"object\": {}}",
+                true));
+    TEST_ASSERT_FALSE(compare_from_string(
+                "{\"False\": false, \"true\": true, \"null\": null, \"number\": 42, \"string\": \"string\", \"array\": [], \"object\": {}}",
+                "{\"true\": true, \"false\": false, \"null\": null, \"number\": 42, \"string\": \"string\", \"array\": [], \"object\": {}}",
+                true));
+    TEST_ASSERT_TRUE(compare_from_string(
+                "{\"False\": false, \"true\": true, \"null\": null, \"number\": 42, \"string\": \"string\", \"array\": [], \"object\": {}}",
+                "{\"true\": true, \"false\": false, \"null\": null, \"number\": 42, \"string\": \"string\", \"array\": [], \"object\": {}}",
+                false));
+    TEST_ASSERT_FALSE(compare_from_string(
+                "{\"Flse\": false, \"true\": true, \"null\": null, \"number\": 42, \"string\": \"string\", \"array\": [], \"object\": {}}",
+                "{\"true\": true, \"false\": false, \"null\": null, \"number\": 42, \"string\": \"string\", \"array\": [], \"object\": {}}",
+                false));
+}
+
+int main(void)
+{
+    UNITY_BEGIN();
+
+    RUN_TEST(cjson_compare_should_compare_null_pointer_as_not_equal);
+    RUN_TEST(cjson_compare_should_compare_invalid_as_not_equal);
+    RUN_TEST(cjson_compare_should_compare_numbers);
+    RUN_TEST(cjson_compare_should_compare_booleans);
+    RUN_TEST(cjson_compare_should_compare_null);
+    RUN_TEST(cjson_compare_should_not_accept_invalid_types);
+    RUN_TEST(cjson_compare_should_compare_strings);
+    RUN_TEST(cjson_compare_should_compare_raw);
+    RUN_TEST(cjson_compare_should_compare_arrays);
+    RUN_TEST(cjson_compare_should_compare_objects);
+
+    return UNITY_END();
+}