scalar-clone: add test coverage

Create a new test file ('t9211-scalar-clone.sh') to exercise the options and
behavior of the 'scalar clone' command. Each test clones to a unique target
location and cleans up the cloned repo only when the test passes. This
ensures that failed tests' artifacts are captured in CI artifacts for
further debugging.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t9211-scalar-clone.sh

@@ -0,0 +1,151 @@
+#!/bin/sh
+
+test_description='test the `scalar clone` subcommand'
+
+. ./test-lib.sh
+
+GIT_TEST_MAINT_SCHEDULER="crontab:test-tool crontab cron.txt,launchctl:true,schtasks:true"
+export GIT_TEST_MAINT_SCHEDULER
+
+test_expect_success 'set up repository to clone' '
+	rm -rf .git &&
+	git init to-clone &&
+	(
+		cd to-clone &&
+		git branch -m base &&
+
+		test_commit first &&
+		test_commit second &&
+		test_commit third &&
+
+		git switch -c parallel first &&
+		mkdir -p 1/2 &&
+		test_commit 1/2/3 &&
+
+		git switch base &&
+
+		# By default, permit
+		git config uploadpack.allowfilter true &&
+		git config uploadpack.allowanysha1inwant true
+	)
+'
+
+cleanup_clone () {
+	rm -rf "$1"
+}
+
+test_expect_success 'creates content in enlistment root' '
+	enlistment=cloned &&
+
+	scalar clone "file://$(pwd)/to-clone" $enlistment &&
+	ls -A $enlistment >enlistment-root &&
+	test_line_count = 1 enlistment-root &&
+	test_path_is_dir $enlistment/src &&
+	test_path_is_dir $enlistment/src/.git &&
+
+	cleanup_clone $enlistment
+'
+
+test_expect_success 'with spaces' '
+	enlistment="cloned with space" &&
+
+	scalar clone "file://$(pwd)/to-clone" "$enlistment" &&
+	test_path_is_dir "$enlistment" &&
+	test_path_is_dir "$enlistment/src" &&
+	test_path_is_dir "$enlistment/src/.git" &&
+
+	cleanup_clone "$enlistment"
+'
+
+test_expect_success 'partial clone if supported by server' '
+	enlistment=partial-clone &&
+
+	scalar clone "file://$(pwd)/to-clone" $enlistment &&
+
+	(
+		cd $enlistment/src &&
+
+		# Two promisor packs: one for refs, the other for blobs
+		ls .git/objects/pack/pack-*.promisor >promisorlist &&
+		test_line_count = 2 promisorlist
+	) &&
+
+	cleanup_clone $enlistment
+'
+
+test_expect_success 'fall back on full clone if partial unsupported' '
+	enlistment=no-partial-support &&
+
+	test_config -C to-clone uploadpack.allowfilter false &&
+	test_config -C to-clone uploadpack.allowanysha1inwant false &&
+
+	scalar clone "file://$(pwd)/to-clone" $enlistment 2>err &&
+	grep "filtering not recognized by server, ignoring" err &&
+
+	(
+		cd $enlistment/src &&
+
+		# Still get a refs promisor file, but none for blobs
+		ls .git/objects/pack/pack-*.promisor >promisorlist &&
+		test_line_count = 1 promisorlist
+	) &&
+
+	cleanup_clone $enlistment
+'
+
+test_expect_success 'initializes sparse-checkout by default' '
+	enlistment=sparse &&
+
+	scalar clone "file://$(pwd)/to-clone" $enlistment &&
+	(
+		cd $enlistment/src &&
+		test_cmp_config true core.sparseCheckout &&
+		test_cmp_config true core.sparseCheckoutCone
+	) &&
+
+	cleanup_clone $enlistment
+'
+
+test_expect_success '--full-clone does not create sparse-checkout' '
+	enlistment=full-clone &&
+
+	scalar clone --full-clone "file://$(pwd)/to-clone" $enlistment &&
+	(
+		cd $enlistment/src &&
+		test_cmp_config "" --default "" core.sparseCheckout &&
+		test_cmp_config "" --default "" core.sparseCheckoutCone
+	) &&
+
+	cleanup_clone $enlistment
+'
+
+test_expect_success '--single-branch clones HEAD only' '
+	enlistment=single-branch &&
+
+	scalar clone --single-branch "file://$(pwd)/to-clone" $enlistment &&
+	(
+		cd $enlistment/src &&
+		git for-each-ref refs/remotes/origin >out &&
+		test_line_count = 1 out &&
+		grep "refs/remotes/origin/base" out
+	) &&
+
+	cleanup_clone $enlistment
+'
+
+test_expect_success '--no-single-branch clones all branches' '
+	enlistment=no-single-branch &&
+
+	scalar clone --no-single-branch "file://$(pwd)/to-clone" $enlistment &&
+	(
+		cd $enlistment/src &&
+		git for-each-ref refs/remotes/origin >out &&
+		test_line_count = 2 out &&
+		grep "refs/remotes/origin/base" out &&
+		grep "refs/remotes/origin/parallel" out
+	) &&
+
+	cleanup_clone $enlistment
+'
+
+test_done