test-lib-functions: add commit_body helper

Extracting the message body of a commit -- running "git cat-file commit" and stripping everything up to and including the first blank line with "sed" -- is spelled out in about 60 places across the test suite. Add a helper for it, so that the operation is written once instead of being copied around. The commit object goes to a temporary file rather than into a pipe, because a pipeline reports only its last command's exit status, so a failure of "git cat-file" would go unnoticed. Signed-off-by: Shlok Kulshreshtha <diy2903@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Shlok Kulshreshtha committed Jul 27, 2026 at 15:26 UTC a592d6feb3d47a1fcd6be5b4c8136e116c26ffbc
2 files changed +19
t/README
+11
@@ -945,6 +945,17 @@ see test-lib-functions.sh for the full list and their options.
945 Merges the given rev using the given message. Like test_commit,
946 creates a tag and calls test_tick before committing.
947
948 + - commit_body <rev>
949 +
950 + Print the message body of <rev>, i.e. the contents of its commit
951 + object with the header removed. Use this instead of piping
952 + "git cat-file commit" into "sed", which would hide a failure of
953 + the git command.
954 +
955 + Example:
956 +
957 + commit_body HEAD >actual
958 +
959 - test_set_prereq <prereq>
960
961 Set a test prerequisite to be used later with test_have_prereq. The
t/test-lib-functions.sh
+8
@@ -1433,6 +1433,14 @@ test_commit_message () {
1433 test_cmp "$msg_file" actual.msg
1434 }
1435
1436 +# Print the message body of a commit
1437 +# Usage: commit_body <rev>
1438 +commit_body () {
1439 + git cat-file commit "$1" >.commit &&
1440 + sed -e "1,/^$/d" .commit &&
1441 + rm -f .commit
1442 +}
1443 +
1444 # Compare paths respecting core.ignoreCase
1445 test_cmp_fspath () {
1446 if test "x$1" = "x$2"