When serializing with JSON_C_TO_STRING_PRETTY set, keep the opening and closing curly or square braces on same line for empty objects or arrays. Issue #778.

ChangeLog

@@ -1,4 +1,21 @@
 
+0.17 (future release)
+========================================
+
+Deprecated and removed features:
+--------------------------------
+* ...
+
+New features
+------------
+* ...
+
+Significant changes and bug fixes
+---------------------------------
+* When serializing with JSON_C_TO_STRING_PRETTY set, keep the opening and 
+  closing curly or square braces on same line for empty objects or arrays.
+
+
 0.16 (up to commit 66dcdf5, 2022-04-13)
 ========================================
 

json_object.c

@@ -460,16 +460,14 @@ static int json_object_object_to_json_string(struct json_object *jso, struct pri
 	struct json_object_iter iter;
 
 	printbuf_strappend(pb, "{" /*}*/);
-	if (flags & JSON_C_TO_STRING_PRETTY)
-		printbuf_strappend(pb, "\n");
 	json_object_object_foreachC(jso, iter)
 	{
 		if (had_children)
 		{
 			printbuf_strappend(pb, ",");
-			if (flags & JSON_C_TO_STRING_PRETTY)
-				printbuf_strappend(pb, "\n");
 		}
+		if (flags & JSON_C_TO_STRING_PRETTY)
+			printbuf_strappend(pb, "\n");
 		had_children = 1;
 		if (flags & JSON_C_TO_STRING_SPACED && !(flags & JSON_C_TO_STRING_PRETTY))
 			printbuf_strappend(pb, " ");
@@ -485,10 +483,9 @@ static int json_object_object_to_json_string(struct json_object *jso, struct pri
 		else if (iter.val->_to_json_string(iter.val, pb, level + 1, flags) < 0)
 			return -1;
 	}
-	if (flags & JSON_C_TO_STRING_PRETTY)
+	if ((flags & JSON_C_TO_STRING_PRETTY) && had_children)
 	{
-		if (had_children)
-			printbuf_strappend(pb, "\n");
+		printbuf_strappend(pb, "\n");
 		indent(pb, level, flags);
 	}
 	if (flags & JSON_C_TO_STRING_SPACED && !(flags & JSON_C_TO_STRING_PRETTY))
@@ -1381,17 +1378,15 @@ static int json_object_array_to_json_string(struct json_object *jso, struct prin
 	size_t ii;
 
 	printbuf_strappend(pb, "[");
-	if (flags & JSON_C_TO_STRING_PRETTY)
-		printbuf_strappend(pb, "\n");
 	for (ii = 0; ii < json_object_array_length(jso); ii++)
 	{
 		struct json_object *val;
 		if (had_children)
 		{
 			printbuf_strappend(pb, ",");
-			if (flags & JSON_C_TO_STRING_PRETTY)
-				printbuf_strappend(pb, "\n");
 		}
+		if (flags & JSON_C_TO_STRING_PRETTY)
+			printbuf_strappend(pb, "\n");
 		had_children = 1;
 		if (flags & JSON_C_TO_STRING_SPACED && !(flags & JSON_C_TO_STRING_PRETTY))
 			printbuf_strappend(pb, " ");
@@ -1402,10 +1397,9 @@ static int json_object_array_to_json_string(struct json_object *jso, struct prin
 		else if (val->_to_json_string(val, pb, level + 1, flags) < 0)
 			return -1;
 	}
-	if (flags & JSON_C_TO_STRING_PRETTY)
+	if ((flags & JSON_C_TO_STRING_PRETTY) && had_children)
 	{
-		if (had_children)
-			printbuf_strappend(pb, "\n");
+		printbuf_strappend(pb, "\n");
 		indent(pb, level, flags);
 	}
 

tests/test1.c

@@ -311,6 +311,11 @@ int main(int argc, char **argv)
 	{
 		printf("\t%s: %s\n", key, json_object_to_json_string(val));
 	}
+
+	json_object *empty_array = json_object_new_array();
+	json_object *empty_obj = json_object_new_object();
+	json_object_object_add(my_object, "empty_array", empty_array);
+	json_object_object_add(my_object, "empty_obj", empty_obj);
 	printf("my_object.to_string()=%s\n", json_object_to_json_string(my_object));
 
 	json_object_put(my_array);

tests/test1.expected

@@ -75,4 +75,4 @@ my_object=
 	foo: "bar"
 	bool0: false
 	bool1: true
-my_object.to_string()={ "abc": 12, "foo": "bar", "bool0": false, "bool1": true }
+my_object.to_string()={ "abc": 12, "foo": "bar", "bool0": false, "bool1": true, "empty_array": [ ], "empty_obj": { } }

tests/test1Formatted_plain.expected

@@ -75,4 +75,4 @@ my_object=
 	foo: "bar"
 	bool0: false
 	bool1: true
-my_object.to_string()={"abc":12,"foo":"bar","bool0":false,"bool1":true}
+my_object.to_string()={"abc":12,"foo":"bar","bool0":false,"bool1":true,"empty_array":[],"empty_obj":{}}

tests/test1Formatted_pretty.expected

@@ -97,5 +97,7 @@ my_object.to_string()={
   "abc":12,
   "foo":"bar",
   "bool0":false,
-  "bool1":true
+  "bool1":true,
+  "empty_array":[],
+  "empty_obj":{}
 }

tests/test1Formatted_spaced.expected

@@ -75,4 +75,4 @@ my_object=
 	foo: "bar"
 	bool0: false
 	bool1: true
-my_object.to_string()={ "abc": 12, "foo": "bar", "bool0": false, "bool1": true }
+my_object.to_string()={ "abc": 12, "foo": "bar", "bool0": false, "bool1": true, "empty_array": [ ], "empty_obj": { } }

tests/test1Formatted_spaced_pretty.expected

@@ -97,5 +97,7 @@ my_object.to_string()={
   "abc": 12,
   "foo": "bar",
   "bool0": false,
-  "bool1": true
+  "bool1": true,
+  "empty_array": [],
+  "empty_obj": {}
 }

tests/test1Formatted_spaced_pretty_pretty_tab.expected

@@ -97,5 +97,7 @@ my_object.to_string()={
 	"abc": 12,
 	"foo": "bar",
 	"bool0": false,
-	"bool1": true
+	"bool1": true,
+	"empty_array": [],
+	"empty_obj": {}
 }