# Helper functions used by interactive rebase tests.

# After setting the fake editor with this function, you can
#
# - override the commit message with $FAKE_COMMIT_MESSAGE
# - amend the commit message with $FAKE_COMMIT_AMEND
# - copy the original commit message to a file with $FAKE_MESSAGE_COPY
# - check that non-commit messages have a certain line count with $EXPECT_COUNT
# - check the commit count in the commit message header with $EXPECT_HEADER_COUNT
# - rewrite a rebase -i script as directed by $FAKE_LINES.
#   $FAKE_LINES consists of a sequence of words separated by spaces;
#   spaces inside the words are encoded as underscores.
#   The following words are possible:
#
#   "<cmd>" -- override the command for the next line specification. Can be
#       "pick", "squash", "fixup[_-(c|C)]", "edit", "reword", "drop",
#       "merge[_-(c|C)_<rev>]", or "bad" for an invalid command.
#
#   "<lineno>" -- add a command, using the specified line as a template.
#       If the command has not been overridden, the line will be copied
#       verbatim, usually resulting in a "pick" line.
#
#   "fakesha" -- add a command ("pick" by default), using a fake SHA1.
#
#   "exec_[command...]", "break" -- add the specified command.
#
#   "#" -- Add a comment line.
#
#   ">" -- Add a blank line.

set_fake_editor () {
	write_script fake-editor.sh <<-\EOF
	case "$1" in
	*/COMMIT_EDITMSG)
		test -z "$EXPECT_HEADER_COUNT" ||
			test "$EXPECT_HEADER_COUNT" = "$(sed -n '1s/^# This is a combination of \(.*\) commits\./\1/p' < "$1")" ||
			exit
		test -z "$FAKE_COMMIT_MESSAGE" || echo "$FAKE_COMMIT_MESSAGE" > "$1"
		test -z "$FAKE_COMMIT_AMEND" || echo "$FAKE_COMMIT_AMEND" >> "$1"
		test -z "$FAKE_MESSAGE_COPY" || cat "$1" >"$FAKE_MESSAGE_COPY"
		exit
		;;
	esac
	test -z "$EXPECT_COUNT" ||
		test "$EXPECT_COUNT" = $(sed -e '/^#/d' -e '/^$/d' < "$1" | wc -l) ||
		exit
	test -z "$FAKE_LINES" && exit
	grep -v '^#' < "$1" > "$1".tmp
	rm -f "$1"
	echo 'rebase -i script before editing:'
	cat "$1".tmp
	action=\&
	for line in $FAKE_LINES; do
		case $line in
		pick|p|squash|s|fixup|f|edit|e|reword|r|drop|d|label|l|reset|t|merge|m)
			action="$line";;
		exec_*|x_*|break|b)
			echo "$line" | sed 's/_/ /g' >> "$1";;
		merge_*|fixup_*)
			action=$(echo "$line" | sed 's/_/ /g');;
		"#")
			echo '# comment' >> "$1";;
		">")
			echo >> "$1";;
		bad)
			action="pickled";;
		fakesha)
			test \& != "$action" || action=pick
			echo "$action XXXXXXX False commit" >> "$1"
			action=\&;;
		*)
			sed -n "${line}s/^[a-z][a-z]*/$action/p" < "$1".tmp >> "$1"
			action=\&;;
		esac
	done
	echo 'rebase -i script after editing:'
	cat "$1"
	EOF

	test_set_editor "$(pwd)/fake-editor.sh"
}

# After set_cat_todo_editor, rebase -i will write the todo list (ignoring
# blank lines and comments) to stdout, and exit failure (so you should run
# it with test_must_fail).  This can be used to verify the expected user
# experience, for todo list changes that do not affect the outcome of
# rebase; or as an extra check in addition to checking the outcome.

set_cat_todo_editor () {
	write_script fake-editor.sh <<-\EOF
	grep "^[^#]" "$1"
	exit 1
	EOF
	test_set_editor "$(pwd)/fake-editor.sh"
}

# checks that the revisions in "$2" represent a linear range with the
# subjects in "$1"
test_linear_range () {
	revlist_merges=$(git rev-list --merges "$2") &&
	test -z "$revlist_merges" &&
	expected=$1
	set -- $(git log --reverse --format=%s "$2")
	test "$expected" = "$*"
}

reset_rebase () {
	test_might_fail git rebase --abort &&
	git reset --hard &&
	git clean -f
}

cherry_pick () {
	git cherry-pick -n "$2" &&
	git commit -m "$1" &&
	git tag "$1"
}

revert () {
	git revert -n "$2" &&
	git commit -m "$1" &&
	git tag "$1"
}

make_empty () {
	git commit --allow-empty -m "$1" &&
	git tag "$1"
}

# Call this (inside test_expect_success) at the end of a test file to
# check that no tests have changed editor related environment
# variables or config settings
test_editor_unchanged () {
	# We're only interested in exported variables hence 'sh -c'
	sh -c 'cat >actual <<-EOF
	EDITOR=$EDITOR
	FAKE_COMMIT_AMEND=$FAKE_COMMIT_AMEND
	FAKE_COMMIT_MESSAGE=$FAKE_COMMIT_MESSAGE
	FAKE_LINES=$FAKE_LINES
	GIT_EDITOR=$GIT_EDITOR
	GIT_SEQUENCE_EDITOR=$GIT_SEQUENCE_EDITOR
	core.editor=$(git config core.editor)
	sequence.editor=$(git config sequence.editor)
	EOF'
	cat >expect <<-\EOF
	EDITOR=:
	FAKE_COMMIT_AMEND=
	FAKE_COMMIT_MESSAGE=
	FAKE_LINES=
	GIT_EDITOR=
	GIT_SEQUENCE_EDITOR=
	core.editor=
	sequence.editor=
	EOF
	test_cmp expect actual
}

# Set up an editor for testing reword commands
# Checks that there are no uncommitted changes when rewording and that the
# todo-list is reread after each
set_reword_editor () {
	>reword-actual &&
	>reword-oid &&

	# Check rewording keeps the original authorship
	GIT_AUTHOR_NAME="Reword Author"
	GIT_AUTHOR_EMAIL="reword.author@example.com"
	GIT_AUTHOR_DATE=@123456

	write_script reword-sequence-editor.sh <<-\EOF &&
	todo="$(cat "$1")" &&
	echo "exec git log -1 --pretty=format:'%an <%ae> %at%n%B%n' \
		>>reword-actual" >"$1" &&
	printf "%s\n" "$todo" >>"$1"
	EOF

	write_script reword-editor.sh <<-EOF &&
	# Save the oid of the first reworded commit so we can check rebase
	# fast-forwards to it. Also check that we do not write .git/MERGE_MSG
	# when fast-forwarding
	if ! test -s reword-oid
	then
		git rev-parse HEAD >reword-oid &&
		if test -f .git/MERGE_MSG
		then
			echo 1>&2 "error: .git/MERGE_MSG exists"
			exit 1
		fi
	fi &&
	# There should be no uncommitted changes
	git diff --exit-code HEAD &&
	# The todo-list should be re-read after a reword
	GIT_SEQUENCE_EDITOR="\"$PWD/reword-sequence-editor.sh\"" \
		git rebase --edit-todo &&
	echo edited >>"\$1"
	EOF

	test_set_editor "$PWD/reword-editor.sh"
}

# Check the results of a rebase after calling set_reword_editor
# Pass the commits that were reworded in the order that they were picked
# Expects the first pick to be a fast-forward
check_reworded_commits () {
	test_cmp_rev "$(cat reword-oid)" "$1^{commit}" &&
	git log --format="%an <%ae> %at%n%B%nedited%n" --no-walk=unsorted "$@" \
		>reword-expected &&
	test_cmp reword-expected reword-actual &&
	git log --format="%an <%ae> %at%n%B" -n $# --first-parent --reverse \
		>reword-log &&
	test_cmp reword-expected reword-log
}

# usage: set_replace_editor <file>
#
# Replace the todo file with the exact contents of the given file.
# N.B. sets GIT_SEQUENCE_EDITOR rather than EDITOR so it can be
# combined with set_fake_editor to reword commits and replace the
# todo list
set_replace_editor () {
	cat >script <<-\EOF &&
	cat FILENAME >"$1"

	echo 'rebase -i script after editing:'
	cat "$1"
	EOF

	sed -e "s/FILENAME/$1/g" script |
		write_script fake-sequence-editor.sh &&
	test_set_sequence_editor "$(pwd)/fake-sequence-editor.sh"
}