Allow Bytea literal constructor to accept byte array.

Bytea literal constructor now accepts string or []byte a a parameter.

postgres/literal.go

@@ -1,8 +1,9 @@
 package postgres
 
 import (
-	"github.com/go-jet/jet/v2/internal/jet"
 	"time"
+
+	"github.com/go-jet/jet/v2/internal/jet"
 )
 
 // Bool creates new bool literal expression
@@ -48,9 +49,14 @@ var String = jet.String
 // value can be any uuid type with a String method
 var UUID = jet.UUID
 
-// Bytea craates new bytea literal expression
-var Bytea = func(value string) StringExpression {
-	return CAST(jet.String(value)).AS_BYTEA()
+// Bytea creates new bytea literal expression
+var Bytea = func(value interface{}) StringExpression {
+	switch value.(type) {
+	case string, []byte:
+	default:
+		panic("Bytea parameter value has to be of the type string or []byte")
+	}
+	return CAST(jet.Literal(value)).AS_BYTEA()
 }
 
 // Date creates new date literal expression

postgres/literal_test.go

@@ -62,6 +62,11 @@ func TestString(t *testing.T) {
 	assertSerialize(t, String("Some text"), `$1`, "Some text")
 }
 
+func TestBytea(t *testing.T) {
+	assertSerialize(t, Bytea("Some text"), `$1::bytea`, "Some text")
+	assertSerialize(t, Bytea([]byte("Some byte array")), `$1::bytea`, []byte("Some byte array"))
+}
+
 func TestDate(t *testing.T) {
 	assertSerialize(t, Date(2014, time.January, 2), `$1::date`, "2014-01-02")
 	assertSerialize(t, DateT(time.Now()), `$1::date`)

tests/postgres/sample_test.go

@@ -497,3 +497,54 @@ FROM test_sample."User";
 ]
 `)
 }
+
+func TestBytea(t *testing.T) {
+	byteArrHex := "\\x48656c6c6f20476f7068657221"
+	byteArrBin := []byte("\x48\x65\x6c\x6c\x6f\x20\x47\x6f\x70\x68\x65\x72\x21")
+
+	insertStmt := AllTypes.INSERT(AllTypes.Bytea, AllTypes.ByteaPtr).
+		VALUES(byteArrHex, byteArrBin).
+		RETURNING(AllTypes.Bytea, AllTypes.ByteaPtr)
+
+	testutils.AssertStatementSql(t, insertStmt, `
+INSERT INTO test_sample.all_types (bytea, bytea_ptr)
+VALUES ($1, $2)
+RETURNING all_types.bytea AS "all_types.bytea",
+          all_types.bytea_ptr AS "all_types.bytea_ptr";
+`, byteArrHex, byteArrBin)
+
+	var inserted model.AllTypes
+	err := insertStmt.Query(db, &inserted)
+	require.NoError(t, err)
+
+	require.Equal(t, string(*inserted.ByteaPtr), "Hello Gopher!")
+	// It is not possible to initiate bytea column using hex format '\xDEADBEEF' with pq driver.
+	// pq driver always encodes parameter string if destination column is of type bytea.
+	// Probably pq driver error.
+	// require.Equal(t, string(inserted.Bytea), "Hello Gopher!")
+
+	stmt := SELECT(
+		AllTypes.Bytea,
+		AllTypes.ByteaPtr,
+	).FROM(
+		AllTypes,
+	).WHERE(
+		AllTypes.ByteaPtr.EQ(Bytea(byteArrBin)),
+	)
+
+	testutils.AssertStatementSql(t, stmt, `
+SELECT all_types.bytea AS "all_types.bytea",
+     all_types.bytea_ptr AS "all_types.bytea_ptr"
+FROM test_sample.all_types
+WHERE all_types.bytea_ptr = $1::bytea;
+`, byteArrBin)
+
+	var dest model.AllTypes
+
+	err = stmt.Query(db, &dest)
+	require.NoError(t, err)
+
+	require.Equal(t, string(*dest.ByteaPtr), "Hello Gopher!")
+	// Probably pq driver error.
+	// require.Equal(t, string(dest.Bytea), "Hello Gopher!")
+}