1 files changed, 43 insertions, 0 deletions
diff --git a/t/lib-read-tree.sh b/t/lib-read-tree.sh
new file mode 100644
index 0000000000..abc2c6f57f
--- /dev/null
+++ b/t/lib-read-tree.sh
@@ -0,0 +1,43 @@
+#!/bin/sh
+#
+# Helper functions to check if read-tree would succeed/fail as expected with
+# and without the dry-run option. They also test that the dry-run does not
+# write the index and that together with -u it doesn't touch the work tree.
+#
+read_tree_must_succeed () {
+    git ls-files -s >pre-dry-run &&
+    git read-tree -n "$@" &&
+    git ls-files -s >post-dry-run &&
+    test_cmp pre-dry-run post-dry-run &&
+    git read-tree "$@"
+}
+
+read_tree_must_fail () {
+    git ls-files -s >pre-dry-run &&
+    test_must_fail git read-tree -n "$@" &&
+    git ls-files -s >post-dry-run &&
+    test_cmp pre-dry-run post-dry-run &&
+    test_must_fail git read-tree "$@"
+}
+
+read_tree_u_must_succeed () {
+    git ls-files -s >pre-dry-run &&
+    git diff-files -p >pre-dry-run-wt &&
+    git read-tree -n "$@" &&
+    git ls-files -s >post-dry-run &&
+    git diff-files -p >post-dry-run-wt &&
+    test_cmp pre-dry-run post-dry-run &&
+    test_cmp pre-dry-run-wt post-dry-run-wt &&
+    git read-tree "$@"
+}
+
+read_tree_u_must_fail () {
+    git ls-files -s >pre-dry-run &&
+    git diff-files -p >pre-dry-run-wt &&
+    test_must_fail git read-tree -n "$@" &&
+    git ls-files -s >post-dry-run &&
+    git diff-files -p >post-dry-run-wt &&
+    test_cmp pre-dry-run post-dry-run &&
+    test_cmp pre-dry-run-wt post-dry-run-wt &&
+    test_must_fail git read-tree "$@"
+}