2 files changed, 91 insertions, 0 deletions
diff --git a/t/meson.build b/t/meson.build
index a59da26be3..8b3aed14ea 100644
--- a/t/meson.build
+++ b/t/meson.build
@@ -500,6 +500,7 @@ integration_tests = [
   't4067-diff-partial-clone.sh',
   't4068-diff-symmetric-merge-base.sh',
   't4069-remerge-diff.sh',
+  't4070-diff-pairs.sh',
   't4100-apply-stat.sh',
   't4101-apply-nonl.sh',
   't4102-apply-rename.sh',
diff --git a/t/t4070-diff-pairs.sh b/t/t4070-diff-pairs.sh
new file mode 100755
index 0000000000..70deafb860
--- /dev/null
+++ b/t/t4070-diff-pairs.sh
@@ -0,0 +1,90 @@
+#!/bin/sh
+
+test_description='basic diff-pairs tests'
+. ./test-lib.sh
+
+# This creates a diff with added, modified, deleted, renamed, copied, and
+# typechange entries. This includes a submodule to test submodule diff support.
+test_expect_success 'setup' '
+	test_config_global protocol.file.allow always &&
+	git init sub &&
+	test_commit -C sub initial &&
+
+	git init main &&
+	cd main &&
+	echo to-be-gone >deleted &&
+	echo original >modified &&
+	echo now-a-file >symlink &&
+	test_seq 200 >two-hundred &&
+	test_seq 201 500 >five-hundred &&
+	git add . &&
+	test_tick &&
+	git commit -m base &&
+	git tag base &&
+
+	git submodule add ../sub &&
+	echo now-here >added &&
+	echo new >modified &&
+	rm deleted &&
+	mkdir subdir &&
+	echo content >subdir/file &&
+	mv two-hundred renamed &&
+	test_seq 201 500 | sed s/300/modified/ >copied &&
+	rm symlink &&
+	git add -A . &&
+	test_ln_s_add dest symlink &&
+	test_tick &&
+	git commit -m new &&
+	git tag new
+'
+
+test_expect_success 'diff-pairs recreates --raw' '
+	git diff-tree -r -M -C -C -z base new >expect &&
+	git diff-pairs --raw -z >actual <expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'diff-pairs can create -p output' '
+	git diff-tree -p -M -C -C base new >expect &&
+	git diff-tree -r -M -C -C -z base new |
+	git diff-pairs -p -z >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'diff-pairs does not support normal raw diff input' '
+	git diff-tree -r base new |
+	test_must_fail git diff-pairs >out 2>err &&
+
+	echo "usage: working without -z is not supported" >expect &&
+	test_must_be_empty out &&
+	test_cmp expect err
+'
+
+test_expect_success 'diff-pairs does not support tree objects as input' '
+	git diff-tree -z base new |
+	test_must_fail git diff-pairs -z >out 2>err &&
+
+	echo "fatal: tree objects not supported" >expect &&
+	test_must_be_empty out &&
+	test_cmp expect err
+'
+
+test_expect_success 'diff-pairs does not support pathspec arguments' '
+	git diff-tree -r -z base new |
+	test_must_fail git diff-pairs -z -- new >out 2>err &&
+
+	echo "usage: pathspec arguments not supported" >expect &&
+	test_must_be_empty out &&
+	test_cmp expect err
+'
+
+test_expect_success 'diff-pairs explicit queue flush' '
+	git diff-tree -r -M -C -C -z base new >expect &&
+	printf "\0" >>expect &&
+	git diff-tree -r -M -C -C -z base new >>expect &&
+
+	git diff-pairs --raw -z <expect >actual &&
+	test_cmp expect actual
+'
+
+test_done