1 files changed, 74 insertions, 0 deletions
diff --git a/t/lib-commit-graph.sh b/t/lib-commit-graph.sh
new file mode 100755
index 0000000..89b2667
--- /dev/null
+++ b/t/lib-commit-graph.sh
@@ -0,0 +1,74 @@
+#!/bin/sh
+
+# Helper functions for testing commit-graphs.
+
+# Initialize OID cache with oid_version
+test_oid_cache <<-EOF
+oid_version sha1:1
+oid_version sha256:2
+EOF
+
+graph_git_two_modes() {
+	git -c core.commitGraph=true $1 >output &&
+	git -c core.commitGraph=false $1 >expect &&
+	test_cmp expect output
+}
+
+# graph_git_behavior <name> <directory> <branch> <compare>
+#
+# Ensures that a handful of traversal operations produce the same
+# results with and without the commit-graph in use.
+#
+# NOTE: it is a bug to call this function with <directory> containing
+# any characters in $IFS.
+graph_git_behavior() {
+	MSG=$1
+	DIR=$2
+	BRANCH=$3
+	COMPARE=$4
+	test_expect_success "check normal git operations: $MSG" '
+		graph_git_two_modes "${DIR:+-C $DIR} log --oneline $BRANCH" &&
+		graph_git_two_modes "${DIR:+-C $DIR} log --topo-order $BRANCH" &&
+		graph_git_two_modes "${DIR:+-C $DIR} log --graph $COMPARE..$BRANCH" &&
+		graph_git_two_modes "${DIR:+-C $DIR} branch -vv" &&
+		graph_git_two_modes "${DIR:+-C $DIR} merge-base -a $BRANCH $COMPARE"
+	'
+}
+
+graph_read_expect() {
+	OPTIONAL=""
+	NUM_CHUNKS=3
+	DIR="."
+	if test "$1" = -C
+	then
+		shift
+		DIR="$1"
+		shift
+	fi
+	if test -n "$2"
+	then
+		OPTIONAL=" $2"
+		NUM_CHUNKS=$((3 + $(echo "$2" | wc -w)))
+	fi
+	GENERATION_VERSION=2
+	if test -n "$3"
+	then
+		GENERATION_VERSION=$3
+	fi
+	OPTIONS=
+	if test $GENERATION_VERSION -gt 1
+	then
+		OPTIONS=" read_generation_data"
+	fi
+	cat >"$DIR/expect" <<-EOF
+	header: 43475048 1 $(test_oid oid_version) $NUM_CHUNKS 0
+	num_commits: $1
+	chunks: oid_fanout oid_lookup commit_metadata$OPTIONAL
+	options:$OPTIONS
+	EOF
+	(
+		cd "$DIR" &&
+		test-tool read-graph >output &&
+		test_cmp expect output
+	)
+}