Adding app/types/size.go

app/types/size.go

@@ -0,0 +1,35 @@
+package types
+
+import (
+	"github.com/docker/go-units"
+	"gopkg.in/yaml.v3"
+)
+
+// Size is an alias of int64 that can handle sizes represented
+// in human readable strings like "200mb", "20 GB" etc
+
+type Size int64 // Size in bytes.
+
+// Parse a string into number of bytes stored in a int64
+func (s *Size) Parse(value string) error {
+	// Empty strings are not an error, they represents zero bytes.
+	if len(value) < 1 {
+		*s = 0
+		return nil
+	}
+
+	v, err := units.FromHumanSize(value)
+	if err != nil {
+		return err
+	}
+	*s = Size(v)
+	return nil
+}
+
+func (s Size) String() string {
+	return units.HumanSize(float64(s))
+}
+
+func (s *Size) UnmarshalYAML(value *yaml.Node) error {
+	return s.Parse(value.Value)
+}

app/types/size_test.go

@@ -0,0 +1,34 @@
+package types
+
+import "testing"
+
+func TestSize_Parse(t *testing.T) {
+	tests := []struct {
+		name     string
+		value    string
+		expected int64
+		wantErr  bool
+	}{
+		{"Empty", "", 0, false},
+		{"NoDigit", "abcdefg", 0, true},
+		{"Negative", "-10MB", 0, true},
+		{"Invalid prefix", "100WAX", 0, true},
+		{"Multiple spaces between prefix and value", "100  gb", 0, true},
+		{"100kb", "100kb", 100 * 1000, false},
+		{"10MB", "10 MB", 10 * 1000 * 1000, false},
+		{"2gb", "2gb", 2 * 1000 * 1000 * 1000, false},
+		{"4Tb", "4 Tb", 4 * 1000 * 1000 * 1000 * 1000, false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			s := Size(0)
+			if err := s.Parse(tt.value); (err != nil) != tt.wantErr {
+				t.Errorf("Size.Parse() error = %v, wantErr %v", err, tt.wantErr)
+			}
+
+			if int64(s) != tt.expected {
+				t.Errorf("Size = %v, expected %v", s, tt.expected)
+			}
+		})
+	}
+}