Add more testing of Encode*

Handle case where TextEncoder is used to a core type that the driver
could otherwise have handled as binary.

values.go

@@ -65,6 +65,33 @@ type NullInt64 struct {
 	Valid bool // Valid is true if Int64 is not NULL
 }
 
+func (n *NullInt64) Scan(rows *Rows, fd *FieldDescription, size int32) error {
+	if size == -1 {
+		n.Int64, n.Valid = 0, false
+		return nil
+	}
+	n.Valid = true
+	n.Int64 = decodeInt8(rows, fd, size)
+	return rows.Err()
+}
+
+func (n *NullInt64) EncodeText() (string, error) {
+	if n.Valid {
+		return strconv.FormatInt(int64(n.Int64), 10), nil
+	} else {
+		return "null", nil
+	}
+}
+
+func (n *NullInt64) EncodeBinary(w *WriteBuf) error {
+	if !n.Valid {
+		w.WriteInt32(-1)
+		return nil
+	}
+
+	return encodeInt8(w, n.Int64)
+}
+
 var literalPattern *regexp.Regexp = regexp.MustCompile(`\$\d+`)
 
 // QuoteString escapes and quotes a string making it safe for interpolation
@@ -96,70 +123,55 @@ func SanitizeSql(sql string, args ...interface{}) (output string, err error) {
 			return
 		}
 
-		switch arg := args[n-1].(type) {
-		case string:
-			return QuoteString(arg)
-		case int:
-			return strconv.FormatInt(int64(arg), 10)
-		case int8:
-			return strconv.FormatInt(int64(arg), 10)
-		case int16:
-			return strconv.FormatInt(int64(arg), 10)
-		case int32:
-			return strconv.FormatInt(int64(arg), 10)
-		case int64:
-			return strconv.FormatInt(int64(arg), 10)
-		case time.Time:
-			return QuoteString(arg.Format("2006-01-02 15:04:05.999999 -0700"))
-		case uint:
-			return strconv.FormatUint(uint64(arg), 10)
-		case uint8:
-			return strconv.FormatUint(uint64(arg), 10)
-		case uint16:
-			return strconv.FormatUint(uint64(arg), 10)
-		case uint32:
-			return strconv.FormatUint(uint64(arg), 10)
-		case uint64:
-			return strconv.FormatUint(uint64(arg), 10)
-		case float32:
-			return strconv.FormatFloat(float64(arg), 'f', -1, 32)
-		case float64:
-			return strconv.FormatFloat(arg, 'f', -1, 64)
-		case bool:
-			return strconv.FormatBool(arg)
-		case []byte:
-			return `E'\\x` + hex.EncodeToString(arg) + `'`
-		case nil:
-			return "null"
-		case TextEncoder:
-			var s string
-			s, err = arg.EncodeText()
-			return s
-		default:
-			err = SerializationError(fmt.Sprintf("%T is not a core type and it does not implement TextEncoder", arg))
-			return ""
-		}
+		var s string
+		s, err = sanitizeArg(args[n-1])
+		return s
 	}
 
 	output = literalPattern.ReplaceAllStringFunc(sql, replacer)
 	return
 }
 
-func (n *NullInt64) Scan(rows *Rows, fd *FieldDescription, size int32) error {
-	if size == -1 {
-		n.Int64, n.Valid = 0, false
-		return nil
-	}
-	n.Valid = true
-	n.Int64 = decodeInt8(rows, fd, size)
-	return rows.Err()
-}
-
-func (n *NullInt64) EncodeText() (string, error) {
-	if n.Valid {
-		return strconv.FormatInt(int64(n.Int64), 10), nil
-	} else {
+func sanitizeArg(arg interface{}) (string, error) {
+	switch arg := arg.(type) {
+	case string:
+		return QuoteString(arg), nil
+	case int:
+		return strconv.FormatInt(int64(arg), 10), nil
+	case int8:
+		return strconv.FormatInt(int64(arg), 10), nil
+	case int16:
+		return strconv.FormatInt(int64(arg), 10), nil
+	case int32:
+		return strconv.FormatInt(int64(arg), 10), nil
+	case int64:
+		return strconv.FormatInt(int64(arg), 10), nil
+	case time.Time:
+		return QuoteString(arg.Format("2006-01-02 15:04:05.999999 -0700")), nil
+	case uint:
+		return strconv.FormatUint(uint64(arg), 10), nil
+	case uint8:
+		return strconv.FormatUint(uint64(arg), 10), nil
+	case uint16:
+		return strconv.FormatUint(uint64(arg), 10), nil
+	case uint32:
+		return strconv.FormatUint(uint64(arg), 10), nil
+	case uint64:
+		return strconv.FormatUint(uint64(arg), 10), nil
+	case float32:
+		return strconv.FormatFloat(float64(arg), 'f', -1, 32), nil
+	case float64:
+		return strconv.FormatFloat(arg, 'f', -1, 64), nil
+	case bool:
+		return strconv.FormatBool(arg), nil
+	case []byte:
+		return `E'\\x` + hex.EncodeToString(arg) + `'`, nil
+	case nil:
 		return "null", nil
+	case TextEncoder:
+		return arg.EncodeText()
+	default:
+		return "", SerializationError(fmt.Sprintf("%T is not a core type and it does not implement TextEncoder", arg))
 	}
 }