[gtksourceview] testsuite: add test to compare regex implementations

[Christian Hergert <chergert src gnome org>]

commit ca271bdbfe76990adf55f0ceeadee4668623b8cb
Author: Christian Hergert <chergert redhat com>
Date:   Fri Jul 2 12:20:56 2021 -0700

    testsuite: add test to compare regex implementations

 testsuite/test-regex.c | 103 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 103 insertions(+)
---
diff --git a/testsuite/test-regex.c b/testsuite/test-regex.c
index 7e636f96..d2cde8e2 100644
--- a/testsuite/test-regex.c
+++ b/testsuite/test-regex.c
@@ -21,6 +21,8 @@
 #include <gtksourceview/gtksource.h>
 #include "gtksourceview/gtksourceregex-private.h"
 
+#include "gtksourceview/implregex-private.h"
+
 static void
 test_slash_c_pattern (void)
 {
@@ -32,12 +34,113 @@ test_slash_c_pattern (void)
        g_assert_null (regex);
 }
 
+static void
+compare_impl_regex_to_g_regex (const char         *subject,
+                               const char         *pattern,
+                               GRegexCompileFlags  compile_flags)
+{
+  GError *err1 = NULL;
+  GError *err2 = NULL;
+  GRegex *reg1 = g_regex_new (pattern, compile_flags, 0, &err1);
+  ImplRegex *reg2 = impl_regex_new (pattern, compile_flags, 0, &err2);
+  GMatchInfo *mi1 = NULL;
+  ImplMatchInfo *mi2 = NULL;
+  gboolean r1, r2;
+
+  g_debug ("Subject: %s", subject);
+  g_debug ("Pattern: %s", pattern);
+
+  g_assert_true ((reg1 == NULL && reg2 == NULL) ||
+                 (reg1 != NULL && reg2 != NULL));
+  g_assert_cmpstr (g_regex_get_pattern (reg1),
+                   ==,
+                   impl_regex_get_pattern (reg2));
+  g_assert_cmpint (g_regex_get_max_lookbehind (reg1),
+                   ==,
+                   impl_regex_get_max_lookbehind (reg2));
+
+  r1 = g_regex_match (reg1, subject, 0, &mi1);
+  r2 = impl_regex_match (reg2, subject, 0, &mi2);
+  g_assert_cmpint (r1, ==, r2);
+
+  for (;;)
+    {
+      gboolean matches1 = g_match_info_matches (mi1);
+      gboolean matches2 = impl_match_info_matches (mi2);
+      int count1, count2;
+      gboolean next1, next2;
+
+      g_assert_cmpint (matches1, ==, matches2);
+
+      if (!matches1)
+        break;
+
+      count1 = g_match_info_get_match_count (mi1);
+      count2 = impl_match_info_get_match_count (mi2);
+      g_assert_cmpint (count1, ==, count2);
+
+      /* Check past boundaries for correctness */
+      for (int i = 0; i < count1 + 2; i++)
+        {
+          int p1_begin, p2_begin;
+          int p1_end, p2_end;
+          char *str1, *str2;
+
+          r1 = g_match_info_fetch_pos (mi1, i, &p1_begin, &p1_end);
+          r2 = impl_match_info_fetch_pos (mi2, i, &p2_begin, &p2_end);
+          g_assert_cmpint (r1, ==, r2);
+          g_assert_cmpint (p1_begin, ==, p2_begin);
+          g_assert_cmpint (p1_end, ==, p2_end);
+
+          str1 = g_match_info_fetch (mi1, i);
+          str2 = impl_match_info_fetch (mi2, i);
+          g_assert_cmpstr (str1, ==, str2);
+
+          g_free (str1);
+          g_free (str2);
+        }
+
+      g_assert_cmpint (g_match_info_is_partial_match (mi1),
+                       ==,
+                       impl_match_info_is_partial_match (mi2));
+
+      next1 = g_match_info_next (mi1, &err1);
+      next2 = impl_match_info_next (mi2, &err2);
+      g_assert_cmpint (next1, ==, next2);
+    }
+
+  g_clear_pointer (&reg1, g_regex_unref);
+  g_clear_pointer (&reg2, impl_regex_unref);
+}
+
+static void
+test_compare (void)
+{
+  /* Note: G_REGEX_OPTIMIZE tests the JIT path in ImplRegex */
+
+  compare_impl_regex_to_g_regex ("aaa\n", "aa", 0);
+  compare_impl_regex_to_g_regex ("aaa\n", "aa", G_REGEX_OPTIMIZE);
+
+  compare_impl_regex_to_g_regex ("aaaa\n", "aa", 0);
+  compare_impl_regex_to_g_regex ("aaaa\n", "aa", G_REGEX_OPTIMIZE);
+
+  compare_impl_regex_to_g_regex ("hello\nworld\n", "\\w+", 0);
+  compare_impl_regex_to_g_regex ("hello\nworld\n", "\\w+", G_REGEX_OPTIMIZE);
+
+  compare_impl_regex_to_g_regex ("aa#bb", "(\\w+)#(\\w+)", 0);
+  compare_impl_regex_to_g_regex ("aa#bb", "(\\w+)#(\\w+)", G_REGEX_OPTIMIZE);
+
+  compare_impl_regex_to_g_regex ("aa#bb cc#dd", "(\\w+)#(\\w+)", 0);
+  compare_impl_regex_to_g_regex ("aa#bb cc#dd", "(\\w+)#(\\w+)", G_REGEX_OPTIMIZE);
+}
+
 int
 main (int argc, char** argv)
 {
        gtk_test_init (&argc, &argv);
 
        g_test_add_func ("/Regex/slash-c", test_slash_c_pattern);
+       g_test_add_func ("/Regex/compare-g-regex", test_compare);
 
        return g_test_run();
 }