service: get rid of bytefmt

- add ByteSize type + Stringer
- add test coverage
- cleanup modules

closes #22

object/utils_test.go

@@ -0,0 +1,48 @@
+package object
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestByteSize_String(t *testing.T) {
+	var cases = []struct {
+		name   string
+		expect string
+		actual ByteSize
+	}{
+		{
+			name:   "101 bytes",
+			expect: "101",
+			actual: ByteSize(101),
+		},
+		{
+			name:   "112.84KB",
+			expect: "112.84KB",
+			actual: ByteSize(115548),
+		},
+		{
+			name:   "80.44MB",
+			expect: "80.44MB",
+			actual: ByteSize(84347453),
+		},
+		{
+			name:   "905.144GB",
+			expect: "905.144GB",
+			actual: ByteSize(971891061884),
+		},
+		{
+			name:   "1.857TB",
+			expect: "1.857TB",
+			actual: ByteSize(2041793092780),
+		},
+	}
+
+	for i := range cases {
+		tt := cases[i]
+		t.Run(tt.name, func(t *testing.T) {
+			require.Equal(t, tt.expect, tt.actual.String())
+		})
+	}
+}