UUID: compatibilty for SQL serialization

CHANGELOG.md

@@ -6,6 +6,10 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/) and this p
 
 ## [Unreleased]
 
+### Added
+
+- `uuid` - SQL library compatibility for type conversion.
+
 ### Fixed
 
 - `bill.Invoice` - remove empty taxes instances.

uuid/sql.go

@@ -0,0 +1,37 @@
+package uuid
+
+import (
+	"database/sql"
+	"database/sql/driver"
+	"fmt"
+)
+
+var _ driver.Valuer = UUID("")
+var _ sql.Scanner = (*UUID)(nil)
+
+// Value implements the driver.Valuer interface.
+func (u UUID) Value() (driver.Value, error) {
+	return u.String(), nil
+}
+
+// Scan implements the sql.Scanner interface.
+// A 16-byte slice will be handled by UnmarshalBinary, while
+// a longer byte slice or a string will be handled by UnmarshalText.
+func (u *UUID) Scan(src interface{}) error {
+	switch src := src.(type) {
+	case UUID:
+		*u = src
+		return nil
+	case []byte:
+		if len(src) == Size {
+			return u.UnmarshalBinary(src)
+		}
+		return u.UnmarshalText(src)
+	case string:
+		uu, err := Parse(src)
+		*u = uu
+		return err
+	}
+
+	return fmt.Errorf("cannot convert %T to UUID", src)
+}

uuid/sql_test.go

@@ -0,0 +1,50 @@
+package uuid_test
+
+import (
+	"testing"
+
+	"github.com/invopop/gobl/uuid"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestValue(t *testing.T) {
+	u := uuid.MustParse("6ba7b810-9dad-11d1-80b4-00c04fd430c8")
+	v, err := u.Value()
+	require.NoError(t, err)
+	assert.Equal(t, u.String(), v)
+}
+
+func TestScan(t *testing.T) {
+	u := uuid.MustParse("6ba7b810-9dad-11d1-80b4-00c04fd430c8")
+	t.Run("with UUID", func(t *testing.T) {
+		var uu uuid.UUID
+		err := uu.Scan(u)
+		require.NoError(t, err)
+		assert.Equal(t, u, uu)
+	})
+	t.Run("with string", func(t *testing.T) {
+		var uu uuid.UUID
+		err := uu.Scan(u.String())
+		require.NoError(t, err)
+		assert.Equal(t, u, uu)
+	})
+	t.Run("with []byte text", func(t *testing.T) {
+		var uu uuid.UUID
+		err := uu.Scan([]byte(u.String()))
+		require.NoError(t, err)
+		assert.Equal(t, u, uu)
+	})
+	t.Run("with bytes", func(t *testing.T) {
+		var uu uuid.UUID
+		err := uu.Scan(u.Bytes())
+		require.NoError(t, err)
+		assert.Equal(t, u, uu)
+	})
+
+	t.Run("with int", func(t *testing.T) {
+		var uu uuid.UUID
+		err := uu.Scan(42)
+		require.ErrorContains(t, err, "cannot convert int to UUI")
+	})
+}

uuid/uuid.go

@@ -32,6 +32,9 @@ const (
 	Zero  UUID = "00000000-0000-0000-0000-000000000000"
 )
 
+// Size is the number of bytes in a UUID.
+const Size = 16
+
 var (
 	regexpSimpleUUID = regexp.MustCompile("^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$")
 )
@@ -195,6 +198,12 @@ func (u UUID) Base64() string {
 	return base64.URLEncoding.WithPadding(base64.NoPadding).EncodeToString(b)
 }
 
+// Bytes returns a byte slice of the UUID.
+func (u UUID) Bytes() []byte {
+	id := parse(u)
+	return id[:]
+}
+
 // ParseBase64 will attempt to decode a Base64 string into a UUID. If the string
 // is already a regular UUID, it will be parsed and returned using the regular
 // Parse method.
@@ -273,6 +282,22 @@ func Normalize(u *UUID) {
 	}
 }
 
+// UnmarshalBinary will convert a 16 byte slice into a UUID
+func (u *UUID) UnmarshalBinary(data []byte) error {
+	id, err := uuid.FromBytes(data)
+	if err != nil {
+		return err
+	}
+	*u = UUID(id.String())
+	return nil
+}
+
+// MarshalBinary implements the encoding.BinaryMarshaler interface.
+func (u *UUID) MarshalBinary() ([]byte, error) {
+	id := parse(*u)
+	return id.MarshalBinary()
+}
+
 // UnmarshalText will ensure the UUID is always a valid UUID when unmarshalling
 // and just return an empty value if incorrect.
 // TODO: Remove this and instead depend on validation to provide more readable errors.

uuid/uuid_test.go

@@ -36,6 +36,12 @@ func TestUUIDParsing(t *testing.T) {
 	assert.True(t, u1.IsZero())
 	u1 = uuid.ShouldParse(v1s)
 	assert.Equal(t, v1s, u1.String())
+
+	t.Run("must parse", func(t *testing.T) {
+		assert.Panics(t, func() {
+			uuid.MustParse("fooo")
+		})
+	})
 }
 
 func TestUUIDIsZero(t *testing.T) {
@@ -73,6 +79,15 @@ func TestUUIDTimestasmp(t *testing.T) {
 	assert.True(t, ts.IsZero())
 }
 
+func TestNodeID(t *testing.T) {
+	a := uuid.NodeID()
+	assert.Len(t, a, 12)
+
+	uuid.SetRandomNodeID()
+	assert.Len(t, uuid.NodeID(), 12)
+	assert.NotEqual(t, a, uuid.NodeID())
+}
+
 func TestUUIDJSON(t *testing.T) {
 	v1s := "03907310-8daa-11eb-8dcd-0242ac130003"
 	type testJSON struct {
@@ -225,6 +240,9 @@ func TestNormalize(t *testing.T) {
 	uuid.Normalize(&u3)
 	assert.Equal(t, "03907310-8daa-11eb-8dcd-0242ac130003", u3.String())
 
+	assert.NotPanics(t, func() {
+		uuid.Normalize(nil)
+	})
 }
 
 func TestUUIDv3(t *testing.T) {
@@ -257,3 +275,22 @@ func TestUUIDBase64(t *testing.T) {
 	require.NoError(t, err)
 	assert.Equal(t, u.String(), u2.String())
 }
+
+func TestUUIDBunary(t *testing.T) {
+	u := uuid.MustParse("f47ac10b-58cc-0372-8567-0e02b2c3d479")
+
+	b := u.Bytes()
+	assert.Equal(t, 16, len(b))
+
+	out, err := u.MarshalBinary()
+	require.NoError(t, err)
+	assert.Equal(t, b, out)
+
+	u2 := new(uuid.UUID)
+	err = u2.UnmarshalBinary(b)
+	require.NoError(t, err)
+
+	u2 = new(uuid.UUID)
+	err = u2.UnmarshalBinary([]byte("invalid"))
+	assert.ErrorContains(t, err, "invalid UUID (got 7 bytes)")
+}