diff --git a/api/layer/multipart_upload_test.go b/api/layer/multipart_upload_test.go
new file mode 100644
index 00000000..5d215239
--- /dev/null
+++ b/api/layer/multipart_upload_test.go
@@ -0,0 +1,108 @@
+package layer
+
+import (
+	"sort"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestTrimAfterUploadIDAndKey(t *testing.T) {
+	uploads := []*UploadInfo{
+		{Key: "j", UploadID: "k"}, // key < id <
+		{Key: "l", UploadID: "p"}, // key < id >
+		{Key: "n", UploadID: "m"}, // key = id <
+		{Key: "n", UploadID: "o"}, // pivot
+		{Key: "n", UploadID: "q"}, // key = id >
+		{Key: "p", UploadID: "h"}, // key > id <
+		{Key: "q", UploadID: "r"}, // key > id >
+	}
+	expectedUploadsListsIndexes := [][]int{
+		{1, 2, 3, 4, 6},
+		{4, 6},
+		{3, 4, 6},
+		{4, 6},
+		{6},
+		{6},
+		{},
+	}
+
+	sort.Slice(uploads, func(i, j int) bool {
+		if uploads[i].Key == uploads[j].Key {
+			return uploads[i].UploadID < uploads[j].UploadID
+		}
+		return uploads[i].Key < uploads[j].Key
+	})
+
+	length := len(uploads)
+
+	t.Run("the last element's key is less, upload id is less", func(t *testing.T) {
+		keys := trimAfterUploadIDAndKey("z", "a", uploads)
+		require.Empty(t, keys)
+		require.Len(t, uploads, length)
+	})
+
+	t.Run("the last element's key is less, upload id is greater", func(t *testing.T) {
+		keys := trimAfterUploadIDAndKey("z", "a", uploads)
+		require.Empty(t, keys)
+		require.Len(t, uploads, length)
+	})
+
+	t.Run("check for uploads", func(t *testing.T) {
+		for i, u := range uploads {
+			list := trimAfterUploadIDAndKey(u.Key, u.UploadID, uploads)
+			require.Equal(t, len(list), len(expectedUploadsListsIndexes[i]))
+			for j, idx := range expectedUploadsListsIndexes[i] {
+				require.Equal(t, list[j], uploads[idx])
+			}
+		}
+	})
+}
+
+func TestTrimAfterUploadKey(t *testing.T) {
+	var (
+		uploadKeys    = []string{"e", "f", "f", "g", "h", "i"}
+		theSameKeyIdx = []int{1, 2}
+		diffKeyIdx    = []int{0, 3}
+		lastIdx       = len(uploadKeys) - 1
+	)
+
+	uploadsInfos := make([]*UploadInfo, 0, len(uploadKeys))
+	for _, k := range uploadKeys {
+		uploadsInfos = append(uploadsInfos, &UploadInfo{Key: k})
+	}
+
+	t.Run("empty list", func(t *testing.T) {
+		keys := trimAfterUploadKey("f", []*UploadInfo{})
+		require.Len(t, keys, 0)
+	})
+
+	t.Run("the last element is less than a key", func(t *testing.T) {
+		keys := trimAfterUploadKey("j", uploadsInfos)
+		require.Empty(t, keys)
+		require.Len(t, uploadsInfos, len(uploadKeys))
+	})
+
+	t.Run("different keys in sequence", func(t *testing.T) {
+		for _, i := range diffKeyIdx {
+			keys := trimAfterUploadKey(uploadKeys[i], uploadsInfos)
+			require.Len(t, keys, len(uploadKeys)-i-1)
+			require.Equal(t, keys, uploadsInfos[i+1:])
+			require.Len(t, uploadsInfos, len(uploadKeys))
+		}
+	})
+
+	t.Run("the same keys in the sequence first element", func(t *testing.T) {
+		for _, i := range theSameKeyIdx {
+			keys := trimAfterUploadKey(uploadKeys[i], uploadsInfos)
+			require.Len(t, keys, 3)
+			require.Equal(t, keys, uploadsInfos[3:])
+			require.Len(t, uploadsInfos, len(uploadKeys))
+		}
+	})
+
+	t.Run("last element", func(t *testing.T) {
+		keys := trimAfterUploadKey(uploadKeys[lastIdx], uploadsInfos)
+		require.Empty(t, keys)
+	})
+}