parser: Ignore UTF-8 BOM if necessaryhandle-utf8-bom

According to JSON spec BOM shouldn't be part of the JSON data, but
also recommends to tolerate files with a BOM marker. As this is common
in several Windows JSON generators, handle it graceful in json-glib and
skip it for UTF-8 BOM.

Fixes: https://gitlab.gnome.org/GNOME/json-glib/-/issues/56

1 files changed, 27 insertions, 0 deletions

diff --git a/json-glib/tests/reader.c b/json-glib/tests/reader.c
index d0a046b..67a81c3 100644
--- a/json-glib/tests/reader.c
+++ b/json-glib/tests/reader.c
@@ -212,6 +212,32 @@ test_reader_null_value (void)
   g_object_unref (parser);
 }
 
+/* test_reader_skip_bom: Ensure that a BOM Unicode character is skipped when parsing */
+static void
+test_reader_skip_bom (void)
+{
+  JsonParser *parser = json_parser_new ();
+  JsonReader *reader = json_reader_new (NULL);
+  GError *error = NULL;
+  char *path;
+
+  path = g_test_build_filename (G_TEST_DIST, "skip-bom.json", NULL);
+
+  json_parser_load_from_mapped_file (parser, path, &error);
+  g_assert_no_error (error);
+
+  json_reader_set_root (reader, json_parser_get_root (parser));
+
+  json_reader_read_member (reader, "appName");
+  g_assert_true (json_reader_is_value (reader));
+  g_assert_no_error (json_reader_get_error (reader));
+  g_assert_cmpstr (json_reader_get_string_value (reader), ==, "String starts with BOM");
+
+  g_free (path);
+  g_object_unref (reader);
+  g_object_unref (parser);
+}
+
 int
 main (int   argc,
       char *argv[])
@@ -223,6 +249,7 @@ main (int   argc,
   g_test_add_func ("/reader/base-object", test_base_object);
   g_test_add_func ("/reader/level", test_reader_level);
   g_test_add_func ("/reader/null-value", test_reader_null_value);
+  g_test_add_func ("/reader/bom", test_reader_skip_bom);
 
   return g_test_run ();
 }