t7421: introduce a test script for verifying 'summary' output

't7401-submodule-summary.sh' uses 'git add' to add submodules. Therefore,
some commands such as 'git submodule init' and 'git submodule deinit'
do not work as expected.

So, introduce a test script for verifying the 'summary' output for
submodules added using 'git submodule add' and notify regarding the
above mentioned behaviour in t7401 itself.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Signed-off-by: Shourya Shukla <shouryashukla.oo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7401-submodule-summary.sh

@@ -7,6 +7,10 @@ test_description='Summary support for submodules
 
 This test tries to verify the sanity of summary subcommand of git submodule.
 '
+# NOTE: This test script uses 'git add' instead of 'git submodule add' to add
+# submodules to the superproject. Some submodule subcommands such as init and
+# deinit might not work as expected in this script. t7421 does not have this
+# caveat.
 
 . ./test-lib.sh
 

t/t7421-submodule-summary-add.sh

@@ -0,0 +1,69 @@
+#!/bin/sh
+#
+# Copyright (C) 2020 Shourya Shukla
+#
+
+test_description='Summary support for submodules, adding them using git submodule add
+
+This test script tries to verify the sanity of summary subcommand of git submodule
+while making sure to add submodules using `git submodule add` instead of
+`git add` as done in t7401.
+'
+
+. ./test-lib.sh
+
+test_expect_success 'summary test environment setup' '
+	git init sm &&
+	test_commit -C sm "add file" file file-content file-tag &&
+
+	git submodule add ./sm my-subm &&
+	test_tick &&
+	git commit -m "add submodule"
+'
+
+test_expect_success 'submodule summary output for initialized submodule' '
+	test_commit -C sm "add file2" file2 file2-content file2-tag &&
+	git submodule update --remote &&
+	test_tick &&
+	git commit -m "update submodule" my-subm &&
+	git submodule summary HEAD^ >actual &&
+	rev1=$(git -C sm rev-parse --short HEAD^) &&
+	rev2=$(git -C sm rev-parse --short HEAD) &&
+	cat >expected <<-EOF &&
+	* my-subm ${rev1}...${rev2} (1):
+	  > add file2
+
+	EOF
+	test_cmp expected actual
+'
+
+test_expect_success 'submodule summary output for deinitialized submodule' '
+	git submodule deinit my-subm &&
+	git submodule summary HEAD^ >actual &&
+	test_must_be_empty actual &&
+	git submodule update --init my-subm &&
+	git submodule summary HEAD^ >actual &&
+	rev1=$(git -C sm rev-parse --short HEAD^) &&
+	rev2=$(git -C sm rev-parse --short HEAD) &&
+	cat >expected <<-EOF &&
+	* my-subm ${rev1}...${rev2} (1):
+	  > add file2
+
+	EOF
+	test_cmp expected actual
+'
+
+test_expect_success 'submodule summary output for submodules with changed paths' '
+	git mv my-subm subm &&
+	git commit -m "change submodule path" &&
+	rev=$(git -C sm rev-parse --short HEAD^) &&
+	git submodule summary HEAD^^ -- my-subm >actual 2>err &&
+	test_i18ngrep "fatal:.*my-subm" err &&
+	cat >expected <<-EOF &&
+	* my-subm ${rev}...0000000:
+
+	EOF
+	test_cmp expected actual
+'
+
+test_done