[gtk/wip/otte/css: 39/48] testsuite: Improve diff_with_file() function

[Benjamin Otte <otte src gnome org>]

commit 93cf76b068a752dd90276f461b9f43f8542229a7
Author: Benjamin Otte <otte redhat com>
Date:   Mon Jan 27 02:15:06 2020 +0100

    testsuite: Improve diff_with_file() function
    
    Properly handle diff(1) failing.
    
    In this particular case, the test passed a NULL input file to the diff
    (that was fixed, too) and then diff only found one input file and
    aborted.
    
    But without this fix, we'd also not catch other abortion reasons for
    diff() - as long as it exited in any way, we were happy.

 testsuite/css/parser/test-css-parser.c | 10 +++++
 testsuite/css/style/test-css-style.c   | 81 +++++++++++++++++-----------------
 testsuite/gsk/node-parser.c            | 10 +++++
 3 files changed, 60 insertions(+), 41 deletions(-)
---
diff --git a/testsuite/css/parser/test-css-parser.c b/testsuite/css/parser/test-css-parser.c
index 4ea608ee1d..b2c4f69746 100644
--- a/testsuite/css/parser/test-css-parser.c
+++ b/testsuite/css/parser/test-css-parser.c
@@ -101,6 +101,16 @@ diff_with_file (const char  *file1,
       return NULL;
     }
 
+  if (!g_subprocess_get_successful (process) &&
+      /* this is the condition when the files differ */
+      !(g_subprocess_get_if_exited (process) && g_subprocess_get_exit_status (process) == 1))
+    {
+      g_clear_pointer (&output, g_bytes_unref);
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                   "The `diff' process exited with error status %d",
+                   g_subprocess_get_exit_status (process));
+    }
+
   g_object_unref (process);
   g_bytes_unref (input);
 
diff --git a/testsuite/css/style/test-css-style.c b/testsuite/css/style/test-css-style.c
index 833cc3dc0d..47e80ceacd 100644
--- a/testsuite/css/style/test-css-style.c
+++ b/testsuite/css/style/test-css-style.c
@@ -50,52 +50,49 @@ test_get_other_file (const char *ui_file, const char *extension)
   return g_string_free (file, FALSE);
 }
 
-static char *
+static GBytes *
 diff_with_file (const char  *file1,
                 char        *text,
                 gssize       len,
                 GError     **error)
 {
-  const char *command[] = { "diff", "-u", file1, NULL, NULL };
-  char *diff, *tmpfile;
-  int fd;
-
-  diff = NULL;
-
-  if (len < 0)
-    len = strlen (text);
-  
-  /* write the text buffer to a temporary file */
-  fd = g_file_open_tmp (NULL, &tmpfile, error);
-  if (fd < 0)
+  GSubprocess *process;
+  GBytes *input, *output;
+
+  process = g_subprocess_new (G_SUBPROCESS_FLAGS_STDIN_PIPE
+                              | G_SUBPROCESS_FLAGS_STDOUT_PIPE,
+                              error,
+                              "diff", "-u", file1, "-", NULL);
+  if (process == NULL)
     return NULL;
 
-  if (write (fd, text, len) != (int) len)
+  input = g_bytes_new_static (text, len >= 0 ? len : strlen (text));
+  if (!g_subprocess_communicate (process,
+                                 input,
+                                 NULL,
+                                 &output,
+                                 NULL,
+                                 error))
     {
-      close (fd);
-      g_set_error (error,
-                   G_FILE_ERROR, G_FILE_ERROR_FAILED,
-                   "Could not write data to temporary file '%s'", tmpfile);
-      goto done;
+      g_object_unref (process);
+      g_bytes_unref (input);
+      return NULL;
+    }
+
+  if (!g_subprocess_get_successful (process) &&
+      /* this is the condition when the files differ */
+      !(g_subprocess_get_if_exited (process) && g_subprocess_get_exit_status (process) == 1))
+    {
+      g_clear_pointer (&output, g_bytes_unref);
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                   "The `diff' process exited with error status %d",
+                   g_subprocess_get_exit_status (process));
     }
-  close (fd);
-  command[3] = tmpfile;
-
-  /* run diff command */
-  g_spawn_sync (NULL, 
-                (char **) command,
-                NULL,
-                G_SPAWN_SEARCH_PATH,
-                NULL, NULL,
-               &diff,
-                NULL, NULL,
-                error);
-
-done:
-  g_unlink (tmpfile);
-  g_free (tmpfile);
-
-  return diff;
+
+  g_object_unref (process);
+  g_bytes_unref (input);
+
+  return output;
 }
 
 static void
@@ -115,7 +112,8 @@ load_ui_file (GFile *file, gboolean generate)
 {
   GtkBuilder *builder;
   GtkWidget *window;
-  char *output, *diff;
+  char *output;
+  GBytes *diff;
   char *ui_file, *css_file, *reference_file;
   GtkCssProvider *provider;
   GError *error = NULL;
@@ -151,17 +149,18 @@ load_ui_file (GFile *file, gboolean generate)
     }
 
   reference_file = test_get_other_file (ui_file, ".nodes");
+  g_assert (reference_file != NULL);
 
   diff = diff_with_file (reference_file, output, -1, &error);
   g_assert_no_error (error);
 
-  if (diff && diff[0])
+  if (diff && g_bytes_get_size (diff) > 0)
     {
-      g_test_message ("Resulting output doesn't match reference:\n%s", diff);
+      g_test_message ("Resulting output doesn't match reference:\n%s", (const char *) g_bytes_get_data 
(diff, NULL));
       g_test_fail ();
     }
   g_free (reference_file);
-  g_free (diff);
+  g_clear_pointer (&diff, g_bytes_unref);
 
 out:
   gtk_style_context_remove_provider_for_display (gdk_display_get_default (),
diff --git a/testsuite/gsk/node-parser.c b/testsuite/gsk/node-parser.c
index 69dba1c49f..cd3c930461 100644
--- a/testsuite/gsk/node-parser.c
+++ b/testsuite/gsk/node-parser.c
@@ -90,6 +90,16 @@ diff_with_file (const char  *file1,
       return NULL;
     }
 
+  if (!g_subprocess_get_successful (process) &&
+      /* this is the condition when the files differ */
+      !(g_subprocess_get_if_exited (process) && g_subprocess_get_exit_status (process) == 1))
+    {
+      g_clear_pointer (&output, g_bytes_unref);
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                   "The `diff' process exited with error status %d",
+                   g_subprocess_get_exit_status (process));
+    }
+
   g_object_unref (process);
 
   return output;