sparse-checkout: create 'add' subcommand

When using the sparse-checkout feature, a user may want to incrementally
grow their sparse-checkout pattern set. Allow adding patterns using a
new 'add' subcommand. This is not much different from the 'set'
subcommand, because we still want to allow the '--stdin' option and
interpret inputs as directories when in cone mode and patterns
otherwise.

When in cone mode, we are growing the cone. This may actually reduce the
set of patterns when adding directory A when A/B is already a directory
in the cone. Test the different cases: siblings, parents, ancestors.

When not in cone mode, we can only assume the patterns should be
appended to the sparse-checkout file.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 59 insertions, 0 deletions

diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh
index 7d98209..f9265de 100755
--- a/t/t1091-sparse-checkout-builtin.sh
+++ b/t/t1091-sparse-checkout-builtin.sh
@@ -141,6 +141,21 @@ test_expect_success 'set sparse-checkout using --stdin' '
 	check_files repo "a folder1 folder2"
 '
 
+test_expect_success 'add to sparse-checkout' '
+	cat repo/.git/info/sparse-checkout >expect &&
+	cat >add <<-\EOF &&
+	pattern1
+	/folder1/
+	pattern2
+	EOF
+	cat add >>expect &&
+	git -C repo sparse-checkout add --stdin <add &&
+	git -C repo sparse-checkout list >actual &&
+	test_cmp expect actual &&
+	test_cmp expect repo/.git/info/sparse-checkout &&
+	check_files repo "a folder1 folder2"
+'
+
 test_expect_success 'cone mode: match patterns' '
 	git -C repo config --worktree core.sparseCheckoutCone true &&
 	rm -rf repo/a repo/folder1 repo/folder2 &&
@@ -219,8 +234,52 @@ test_expect_success 'cone mode: set with nested folders' '
 	test_cmp repo/.git/info/sparse-checkout expect
 '
 
+test_expect_success 'cone mode: add independent path' '
+	git -C repo sparse-checkout set deep/deeper1 &&
+	git -C repo sparse-checkout add folder1 &&
+	cat >expect <<-\EOF &&
+	/*
+	!/*/
+	/deep/
+	!/deep/*/
+	/deep/deeper1/
+	/folder1/
+	EOF
+	test_cmp expect repo/.git/info/sparse-checkout &&
+	check_files repo a deep folder1
+'
+
+test_expect_success 'cone mode: add sibling path' '
+	git -C repo sparse-checkout set deep/deeper1 &&
+	git -C repo sparse-checkout add deep/deeper2 &&
+	cat >expect <<-\EOF &&
+	/*
+	!/*/
+	/deep/
+	!/deep/*/
+	/deep/deeper1/
+	/deep/deeper2/
+	EOF
+	test_cmp expect repo/.git/info/sparse-checkout &&
+	check_files repo a deep
+'
+
+test_expect_success 'cone mode: add parent path' '
+	git -C repo sparse-checkout set deep/deeper1 folder1 &&
+	git -C repo sparse-checkout add deep &&
+	cat >expect <<-\EOF &&
+	/*
+	!/*/
+	/deep/
+	/folder1/
+	EOF
+	test_cmp expect repo/.git/info/sparse-checkout &&
+	check_files repo a deep folder1
+'
+
 test_expect_success 'revert to old sparse-checkout on bad update' '
 	test_when_finished git -C repo reset --hard &&
+	git -C repo sparse-checkout set deep &&
 	echo update >repo/deep/deeper2/a &&
 	cp repo/.git/info/sparse-checkout expect &&
 	test_must_fail git -C repo sparse-checkout set deep/deeper1 2>err &&