testing: add test for `Out_Of_Memory` return

tests/core/encoding/json/test_core_json.odin

@@ -4,6 +4,7 @@ import "core:encoding/json"
 import "core:testing"
 import "core:fmt"
 import "core:os"
+import "core:mem/virtual"
 
 TEST_count := 0
 TEST_fail  := 0
@@ -77,6 +78,49 @@ parse_json :: proc(t: ^testing.T) {
 	expect(t, err == nil, msg)
 }
 
+@test
+out_of_memory_in_parse_json :: proc(t: ^testing.T) {
+	arena: virtual.Arena
+	arena_buffer: [256]byte
+	arena_init_error := virtual.arena_init_buffer(&arena, arena_buffer[:])
+	testing.expect(t, arena_init_error == nil, fmt.tprintf("Expected arena initialization to not return error, got: %v\n", arena_init_error))
+
+	context.allocator = virtual.arena_allocator(&arena)
+	
+	json_data := `
+	{
+	  "firstName": "John",
+	  "lastName": "Smith",
+	  "isAlive": true,
+	  "age": 27,
+	  "address": {
+		"streetAddress": "21 2nd Street",
+		"city": "New York",
+		"state": "NY",
+		"postalCode": "10021-3100"
+	  },
+	  "phoneNumbers": [
+		{
+		  "type": "home",
+		  "number": "212 555-1234"
+		},
+		{
+		  "type": "office",
+		  "number": "646 555-4567"
+		}
+	  ],
+	  "children": [],
+	  "spouse": null
+	}
+	`
+
+	_, err := json.parse(transmute([]u8)json_data)
+
+	expected_error := json.Error.Out_Of_Memory
+	msg := fmt.tprintf("Expected `json.parse` to fail with %v, got %v", expected_error, err)
+	expect(t, err == json.Error.Out_Of_Memory, msg)
+}
+
 @test
 marshal_json :: proc(t: ^testing.T) {