From 3d8936153d8a962ace54a055ebdb308b09ca7c97 Mon Sep 17 00:00:00 2001
From: Jeff King <peff@peff.net>
Date: Sat, 25 Feb 2017 04:37:07 -0500
Subject: t: add an interoperability test harness

The current test suite is good at letting you test a
particular version of Git. But it's not very good at letting
you test _two_ versions and seeing how they interact (e.g.,
one cloning from the other).

This commit adds a test harness that will build two
arbitrary versions of git and make it easy to call them from
inside your tests. See the README and the example script for
details.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/interop/interop-lib.sh | 92 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100644 t/interop/interop-lib.sh

(limited to 't/interop/interop-lib.sh')

diff --git a/t/interop/interop-lib.sh b/t/interop/interop-lib.sh
new file mode 100644
index 0000000000..3e0a2911d4
--- /dev/null
+++ b/t/interop/interop-lib.sh
@@ -0,0 +1,92 @@
+# Interoperability testing framework. Each script should source
+# this after setting default $VERSION_A and $VERSION_B variables.
+
+. ../../GIT-BUILD-OPTIONS
+INTEROP_ROOT=$(pwd)
+BUILD_ROOT=$INTEROP_ROOT/build
+
+build_version () {
+	if test -z "$1"
+	then
+		echo >&2 "error: test script did not set default versions"
+		return 1
+	fi
+
+	if test "$1" = "."
+	then
+		git rev-parse --show-toplevel
+		return 0
+	fi
+
+	sha1=$(git rev-parse "$1^{tree}") || return 1
+	dir=$BUILD_ROOT/$sha1
+
+	if test -e "$dir/.built"
+	then
+		echo "$dir"
+		return 0
+	fi
+
+	echo >&2 "==> Building $1..."
+
+	mkdir -p "$dir" || return 1
+
+	(cd "$(git rev-parse --show-cdup)" && git archive --format=tar "$sha1") |
+	(cd "$dir" && tar x) ||
+	return 1
+
+	for config in config.mak config.mak.autogen config.status
+	do
+		if test -e "$INTEROP_ROOT/../../$config"
+		then
+			cp "$INTEROP_ROOT/../../$config" "$dir/" || return 1
+		fi
+	done
+
+	(
+		cd "$dir" &&
+		make $GIT_INTEROP_MAKE_OPTS >&2 &&
+		touch .built
+	) || return 1
+
+	echo "$dir"
+}
+
+# Old versions of git don't have bin-wrappers, so let's give a rough emulation.
+wrap_git () {
+	write_script "$1" <<-EOF
+	GIT_EXEC_PATH="$2"
+	export GIT_EXEC_PATH
+	PATH="$2:\$PATH"
+	export GIT_EXEC_PATH
+	exec git "\$@"
+	EOF
+}
+
+generate_wrappers () {
+	mkdir -p .bin &&
+	wrap_git .bin/git.a "$DIR_A" &&
+	wrap_git .bin/git.b "$DIR_B" &&
+	write_script .bin/git <<-\EOF &&
+	echo >&2 fatal: test tried to run generic git
+	exit 1
+	EOF
+	PATH=$(pwd)/.bin:$PATH
+}
+
+VERSION_A=${GIT_TEST_VERSION_A:-$VERSION_A}
+VERSION_B=${GIT_TEST_VERSION_B:-$VERSION_B}
+
+if ! DIR_A=$(build_version "$VERSION_A") ||
+   ! DIR_B=$(build_version "$VERSION_B")
+then
+	echo >&2 "fatal: unable to build git versions"
+	exit 1
+fi
+
+TEST_DIRECTORY=$INTEROP_ROOT/..
+TEST_OUTPUT_DIRECTORY=$INTEROP_ROOT
+TEST_NO_CREATE_REPO=t
+. "$TEST_DIRECTORY"/test-lib.sh
+
+generate_wrappers || die "unable to set up interop test environment"
-- 
cgit v1.2.3