[PATCH 3/3] checkpatch: suggest including testing evidence

["Ignacio Peña" <ignacio.pena87@gmail.com>]

For non-trivial changes, it's valuable to know how the change was
tested. Add a gentle suggestion when commit messages don't mention
any testing, verification, or validation.

This is a CHECK level notification, not a WARNING, as testing methods
vary greatly depending on the subsystem and type of change.

The check is skipped for very short commit messages (documentation
fixes, typos) where testing information would be excessive.

Link: https://docs.kernel.org/process/submitting-patches.html
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ignacio Pena <ignacio.pena87@gmail.com>
---
 scripts/checkpatch.pl | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 204800232..358310e6c 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -3319,6 +3319,16 @@ sub process {
 		      $commit_log_possible_stack_dump)) {
 			WARN("COMMIT_LOG_LONG_LINE",
 			     "Prefer a maximum 75 chars per line (possible unwrapped commit description?)\n" . $herecurr);
+
+# Suggest including test information for non-trivial changes
+		if ($in_commit_log && !$non_utf8_charset &&
+		    $line !~ /test|verify|tried|ran|checked|confirmed/i &&
+		    $commit_log_lines > 3) {
+			if ($commit_log_long_line eq "" && $commit_log_has_diff) {
+				CHECK("NO_TEST_INFO",
+				      "Consider mentioning how this change was tested\n" . $herecurr);
+			}
+		}
 			$commit_log_long_line = 1;
 		}
 
-- 
2.50.1