[PATCH 4/4] git-commit: add a prepare-commit-msg hook
The prepare-commit-msg hook is run whenever a "fresh" commit message is prepared, just before it is shown in the editor (if it is). It can modify the commit message in-place and/or abort the commit.
It takes two parameters. The first is the source of the commit message, and can be: `message` (if a `\-m` or `\-F` option was given); `template` (if a `\-t` option was given or the configuration option `commit.template` is set); `merge` (if the commit is a merge or a `.git/MERGE_MSG file exists); `squash` (if a `.git/SQUASH_MSG file exists); or a commit id (if a `\-c`, `\-C` or `\--amend` option was given). The second parameter if the name of the file that the commit log message.
The hook is not suppressed by the `\--no-verify` option. However, exiting with non-zero status only aborts the commit if said option is not given to `git-commit`.
While the default hook just adds a Signed-Off-By line at the bottom of the commit messsage, the hook is more intended to build a template for the commit message following project standards, that the user can then edit or discard altogether.
Signed-off-by: Paolo Bonzini <bonzini@gnu.org>
---
Documentation/git-commit.txt | 4
Documentation/hooks.txt | 33 +++
builtin-commit.c | 21 ++
t/t7505-prepare-commit-msg-hook.sh | 303 ++++++++++++++++++++++++++++++++++++
templates/hooks--commit-msg | 3
templates/hooks--prepare-commit-msg | 14 +
6 files changed, 375 insertions(+), 3 deletions(-)
The whole patch series is against the `next' branch.
Show changes to 6 files +375 −3
Documentation/git-commit.txt, Documentation/hooks.txt, builtin-commit.c, t/t7505-prepare-commit-msg-hook.sh, templates/hooks--commit-msg, templates/hooks--prepare-commit-msg
diff --git a/Documentation/git-commit.txt b/Documentation/git-commit.txt
index c3725b2..b4ae61f 100644
--- a/Documentation/git-commit.txt
+++ b/Documentation/git-commit.txt
@@ -280,8 +280,8 @@ order).
HOOKS
-----
-This command can run `commit-msg`, `pre-commit`, and
-`post-commit` hooks. See link:hooks.html[hooks] for more
+This command can run `commit-msg`, `prepare-commit-msg`, `pre-commit`,
+and `post-commit` hooks. See link:hooks.html[hooks] for more
information.
diff --git a/Documentation/hooks.txt b/Documentation/hooks.txt
index e8d80cf..f25bcd5 100644
--- a/Documentation/hooks.txt
+++ b/Documentation/hooks.txt
@@ -55,7 +55,8 @@ This hook is invoked by `git-commit`, and can be bypassed
with `\--no-verify` option. It takes no parameter, and is
invoked before obtaining the proposed commit log message and
making a commit. Exiting with non-zero status from this script
-causes the `git-commit` to abort.
+causes the `git-commit` to abort. This hook can also modify
+the index.
The default 'pre-commit' hook, when enabled, catches introduction
of lines with trailing whitespaces and aborts the commit when
@@ -65,6 +66,36 @@ All the `git-commit` hooks are invoked with the environment
variable `GIT_EDITOR=:` if the command will not bring up an editor
to modify the commit message.
+prepare-commit-msg
+------------------
+
+This hook is invoked by `git-commit` right after preparing the
+default log message, and before the editor is started.
+
+It takes two parameters. The first is the source of the commit
+message, and can be: `message` (if a `\-m` or `\-F` option was
+given); `template` (if a `\-t` option was given or the
+configuration option `commit.template` is set); `merge` (if the
+commit is a merge or a `.git/MERGE_MSG file exists); `squash`
+(if a `.git/SQUASH_MSG file exists); or a commit id (if a
+`\-c`, `\-C` or `\--amend` option was given). The second
+parameter if the name of the file that the commit log message.
+
+The hook is not suppressed by the `\--no-verify` option. However,
+exiting with non-zero status only aborts the commit if said option
+is not given to `git-commit`.
+
+The hook is allowed to edit the message file in place, and
+can be used to augment the default commit message with some
+project standard information. It can also be used for the same
+purpose as the pre-commit message, if the verification has
+to be skipped for automatic commits (e.g. during rebasing).
+
+The default 'prepare-commit-msg' hook adds a Signed-Off-By line
+(doing it with a hook is not necessarily a good idea, but doing
+it in 'commit-msg' is worse because you are not reminded in
+the editor).
+
commit-msg
----------
diff --git a/builtin-commit.c b/builtin-commit.c
index fed549e..1a083f7 100644
--- a/builtin-commit.c
+++ b/builtin-commit.c
@@ -388,36 +388,49 @@ static int prepare_log_message(const char *index_file, const char *prefix)
struct strbuf sb;
char *buffer;
FILE *fp;
+ const char *hook_arg = NULL;
strbuf_init(&sb, 0);
if (message.len) {
strbuf_addbuf(&sb, &message);
+ hook_arg = "message";
} else if (logfile && !strcmp(logfile, "-")) {
if (isatty(0))
fprintf(stderr, "(reading log message from standard input)\n");
if (strbuf_read(&sb, 0, 0) < 0)
die("could not read log from standard input");
+ hook_arg = "message";
} else if (logfile) {
if (strbuf_read_file(&sb, logfile, 0) < 0)
die("could not read log file '%s': %s",
logfile, strerror(errno));
+ hook_arg = "message";
} else if (use_message) {
buffer = strstr(use_message_buffer, "\n\n");
if (!buffer || buffer[2] == '\0')
die("commit has empty message");
strbuf_add(&sb, buffer + 2, strlen(buffer + 2));
+ hook_arg = use_message;
} else if (!stat(git_path("MERGE_MSG"), &statbuf)) {
if (strbuf_read_file(&sb, git_path("MERGE_MSG"), 0) < 0)
die("could not read MERGE_MSG: %s", strerror(errno));
+ hook_arg = "merge";
} else if (!stat(git_path("SQUASH_MSG"), &statbuf)) {
if (strbuf_read_file(&sb, git_path("SQUASH_MSG"), 0) < 0)
die("could not read SQUASH_MSG: %s", strerror(errno));
+ hook_arg = "squash";
} else if (template_file && !stat(template_file, &statbuf)) {
if (strbuf_read_file(&sb, template_file, 0) < 0)
die("could not read %s: %s",
template_file, strerror(errno));
+ hook_arg = "template";
}
+ /* This final case does not modify the template message, it just sets
+ the argument to the prepare-commit-msg hook. */
+ else if (in_merge)
+ hook_arg = "merge";
+
fp = fopen(git_path(commit_editmsg), "w");
if (fp == NULL)
die("could not open %s", git_path(commit_editmsg));
@@ -511,6 +524,14 @@ static int prepare_log_message(const char *index_file, const char *prefix)
return 0;
}
+ /* Note that we always run the hook, even if no_verify! */
+ if (run_hook(index_file, "prepare-commit-msg",
+ git_path(commit_editmsg), hook_arg, NULL) &&
+ !no_verify) {
+ rollback_index_files();
+ return 0;
+ }
+
if (use_editor) {
char index[PATH_MAX];
const char *env[2] = { index, NULL };
diff --git a/t/t7505-prepare-commit-msg-hook.sh b/t/t7505-prepare-commit-msg-hook.sh
new file mode 100755
index 0000000..e632bbe
--- /dev/null
+++ b/t/t7505-prepare-commit-msg-hook.sh
@@ -0,0 +1,303 @@
+#!/bin/sh
+
+test_description='prepare-commit-msg hook'
+
+. ./test-lib.sh
+
+test_expect_success 'with no hook' '
+
+ echo "foo" > file &&
+ git add file &&
+ git commit -m "first"
+
+'
+
+# set up fake editor for interactive editing
+cat > fake-editor <<'EOF'
+#!/bin/sh
+exit 0
+EOF
+chmod +x fake-editor
+FAKE_EDITOR="$(pwd)/fake-editor"
+export FAKE_EDITOR
+
+# now install hook that always succeeds and adds a message
+HOOKDIR="$(git rev-parse --git-dir)/hooks"
+HOOK="$HOOKDIR/prepare-commit-msg"
+mkdir -p "$HOOKDIR"
+cat > "$HOOK" <<'EOF'
+#!/bin/sh
+if test "$2" = HEAD; then
+ set "$1" $(git-rev-parse HEAD)
+fi
+if test "$GIT_EDITOR" = :; then
+ sed -e "1s/.*/${2-default} (no editor)/" "$1" > msg.tmp
+else
+ sed -e "1s/.*/${2-default}/" "$1" > msg.tmp
+fi
+mv msg.tmp "$1"
+exit 0
+EOF
+chmod +x "$HOOK"
+
+echo dummy template > "$(git rev-parse --git-dir)/template"
+
+test_expect_success 'with succeeding hook (-m)' '
+
+ echo "more" >> file &&
+ git add file &&
+ git commit -m "more" &&
+ test "`git log -1 --pretty=format:%s`" = "message (no editor)"
+
+'
+
+test_expect_success 'with succeeding hook (-m editor)' '
+
+ echo "more" >> file &&
+ git add file &&
+ GIT_EDITOR="$FAKE_EDITOR" git commit -e -m "more more" &&
+ test "`git log -1 --pretty=format:%s`" = message
+
+'
+
+test_expect_success 'with succeeding hook (-t)' '
+
+ echo "more" >> file &&
+ git add file &&
+ git commit -t "$(git rev-parse --git-dir)/template" &&
+ test "`git log -1 --pretty=format:%s`" = template
+
+'
+
+test_expect_success 'with succeeding hook (-F)' '
+
+ echo "more" >> file &&
+ git add file &&
+ (echo more | git commit -F -) &&
+ test "`git log -1 --pretty=format:%s`" = "message (no editor)"
+
+'
+
+test_expect_success 'with succeeding hook (-F editor)' '
+
+ echo "more" >> file &&
+ git add file &&
+ (echo more more | GIT_EDITOR="$FAKE_EDITOR" git commit -e -F -) &&
+ test "`git log -1 --pretty=format:%s`" = message
+
+'
+
+test_expect_success 'with succeeding hook (-C)' '
+
+ head=`git rev-parse HEAD` &&
+ echo "more" >> file &&
+ git add file &&
+ git commit -C $head &&
+ test "`git log -1 --pretty=format:%s`" = "$head (no editor)"
+
+'
+
+test_expect_success 'with succeeding hook (editor)' '
+
+ echo "more more" >> file &&
+ git add file &&
+ GIT_EDITOR="$FAKE_EDITOR" git commit &&
+ test "`git log -1 --pretty=format:%s`" = default
+
+'
+
+test_expect_success 'with succeeding hook (--amend)' '
+
+ head=`git rev-parse HEAD` &&
+ echo "more" >> file &&
+ git add file &&
+ GIT_EDITOR="$FAKE_EDITOR" git commit --amend &&
+ test "`git log -1 --pretty=format:%s`" = "$head"
+
+'
+
+test_expect_success 'with succeeding hook (-c)' '
+
+ head=`git rev-parse HEAD` &&
+ echo "more" >> file &&
+ git add file &&
+ GIT_EDITOR="$FAKE_EDITOR" git commit -c $head &&
+ test "`git log -1 --pretty=format:%s`" = "$head"
+
+'
+
+# now a hook that fails
+cat > "$HOOK" << 'EOF'
+#!/bin/sh
+if test "$2" = HEAD; then
+ set "$1" $(git-rev-parse HEAD)
+fi
+if test "$GIT_EDITOR" = :; then
+ sed -e "1s/.*/${2-default} (no editor)/" "$1" > msg.tmp
+else
+ sed -e "1s/.*/${2-default}/" "$1" > msg.tmp
+fi
+mv msg.tmp "$1"
+exit 1
+EOF
+
+test_expect_success 'with failing hook and --no-verify (-m)' '
+
+ echo "more" >> file &&
+ git add file &&
+ git commit --no-verify -m "more" &&
+ test "`git log -1 --pretty=format:%s`" = "message (no editor)"
+
+'
+
+test_expect_success 'with failing hook and --no-verify (-m editor)' '
+
+ echo "more" >> file &&
+ git add file &&
+ GIT_EDITOR="$FAKE_EDITOR" git commit --no-verify -e -m "more more" &&
+ test "`git log -1 --pretty=format:%s`" = message
+
+'
+
+test_expect_success 'with failing hook and --no-verify (-t)' '
+
+ echo "more" >> file &&
+ git add file &&
+ git commit --no-verify -t "$(git rev-parse --git-dir)/template" &&
+ test "`git log -1 --pretty=format:%s`" = template
+
+'
+
+test_expect_success 'with failing hook and --no-verify (-F)' '
+
+ echo "more" >> file &&
+ git add file &&
+ (echo more | git commit --no-verify -F -) &&
+ test "`git log -1 --pretty=format:%s`" = "message (no editor)"
+
+'
+
+test_expect_success 'with failing hook and --no-verify (-F editor)' '
+
+ echo "more" >> file &&
+ git add file &&
+ (echo more more | GIT_EDITOR="$FAKE_EDITOR" git commit --no-verify -e -F -) &&
+ test "`git log -1 --pretty=format:%s`" = message
+
+'
+
+test_expect_success 'with failing hook and --no-verify (-C)' '
+
+ head=`git rev-parse HEAD` &&
+ echo "more" >> file &&
+ git add file &&
+ git commit --no-verify -C $head &&
+ test "`git log -1 --pretty=format:%s`" = "$head (no editor)"
+
+'
+
+test_expect_success 'with failing hook and --no-verify (editor)' '
+
+ echo "more more" >> file &&
+ git add file &&
+ GIT_EDITOR="$FAKE_EDITOR" git commit --no-verify &&
+ test "`git log -1 --pretty=format:%s`" = default
+
+'
+
+test_expect_success 'with failing hook and --no-verify (--amend)' '
+
+ head=`git rev-parse HEAD` &&
+ echo "more" >> file &&
+ git add file &&
+ GIT_EDITOR="$FAKE_EDITOR" git commit --no-verify --amend &&
+ test "`git log -1 --pretty=format:%s`" = "$head"
+
+'
+
+test_expect_success 'with failing hook and --no-verify (-c)' '
+
+ head=`git rev-parse HEAD` &&
+ echo "more" >> file &&
+ git add file &&
+ GIT_EDITOR="$FAKE_EDITOR" git commit --no-verify -c $head &&
+ test "`git log -1 --pretty=format:%s`" = "$head"
+
+'
+
+test_expect_failure 'with failing hook (-m)' '
+
+ echo "more" >> file &&
+ git add file &&
+ git commit -m "more"
+
+'
+
+test_expect_failure 'with failing hook (-m editor)' '
+
+ echo "more" >> file &&
+ git add file &&
+ GIT_EDITOR="$FAKE_EDITOR" git commit -e -m "more more"
+
+'
+
+test_expect_failure 'with failing hook (-t)' '
+
+ echo "more" >> file &&
+ git add file &&
+ git commit -t "$(git rev-parse --git-dir)/template"
+
+'
+
+test_expect_failure 'with failing hook (-F)' '
+
+ echo "more" >> file &&
+ git add file &&
+ (echo more | git commit -F -)
+
+'
+
+test_expect_failure 'with failing hook (-F editor)' '
+
+ echo "more" >> file &&
+ git add file &&
+ (echo more more | GIT_EDITOR="$FAKE_EDITOR" git commit -e -F -)
+
+'
+
+test_expect_failure 'with failing hook (-C)' '
+
+ head=`git rev-parse HEAD` &&
+ echo "more" >> file &&
+ git add file &&
+ git commit -C $head
+
+'
+
+test_expect_failure 'with failing hook (editor)' '
+
+ echo "more more" >> file &&
+ git add file &&
+ GIT_EDITOR="$FAKE_EDITOR" git commit
+
+'
+
+test_expect_failure 'with failing hook (--amend)' '
+
+ echo "more" >> file &&
+ git add file &&
+ GIT_EDITOR="$FAKE_EDITOR" git commit --amend
+
+'
+
+test_expect_failure 'with failing hook (-c)' '
+
+ head=`git rev-parse HEAD` &&
+ echo "more" >> file &&
+ git add file &&
+ GIT_EDITOR="$FAKE_EDITOR" git commit -c $head
+
+'
+
+
+test_done
diff --git a/templates/hooks--commit-msg b/templates/hooks--commit-msg
index c5cdb9d..4ef86eb 100644
--- a/templates/hooks--commit-msg
+++ b/templates/hooks--commit-msg
@@ -9,6 +9,9 @@
# To enable this hook, make this file executable.
# Uncomment the below to add a Signed-off-by line to the message.
+# Doing this in a hook is a bad idea in general, but the prepare-commit-msg
+# hook is more suited to it.
+#
# SOB=$(git var GIT_AUTHOR_IDENT | sed -n 's/^\(.*>\).*$/Signed-off-by: \1/p')
# grep -qs "^$SOB" "$1" || echo "$SOB" >> "$1"
diff --git a/templates/hooks--prepare-commit-msg b/templates/hooks--prepare-commit-msg
new file mode 100644
index 0000000..176283b
--- /dev/null
+++ b/templates/hooks--prepare-commit-msg
@@ -0,0 +1,14 @@
+#!/bin/sh
+#
+# An example hook script to prepare the commit log message.
+# Called by git-commit with one argument, the name of the file
+# that has the commit message. The hook should exit with non-zero
+# status after issuing an appropriate message if it wants to stop the
+# commit. The hook is allowed to edit the commit message file.
+#
+# To enable this hook, make this file executable.
+
+# This example adds a Signed-off-by line to the message, that can
+# still be edited.
+SOB=$(git var GIT_AUTHOR_IDENT | sed -n 's/^\(.*>\).*$/Signed-off-by: \1/p')
+grep -qs "^$SOB" "$1" || echo "$SOB" >> "$1"
Paolo Bonzini
