fix: use xerrors.Errorf instead of fmt.Errorf (#52)

mapper.go

@@ -3,8 +3,9 @@ package exql
 import (
 	"database/sql"
 	"errors"
-	"fmt"
 	"reflect"
+
+	"golang.org/x/xerrors"
 )
 
 // Error returned when record not found
@@ -44,7 +45,7 @@ func NewSerialMapper(s ColumnSplitter) SerialMapper {
 	return &serialMapper{splitter: s}
 }
 
-var errMapDestination = fmt.Errorf("destination must be a pointer of struct")
+var errMapDestination = xerrors.Errorf("destination must be a pointer of struct")
 
 // MapRow reads data from single row and maps those columns into destination struct.
 // pointerOfStruct MUST BE a pointer of struct.
@@ -85,7 +86,7 @@ func MapRow(row *sql.Rows, pointerOfStruct interface{}) error {
 	return ErrRecordNotFound
 }
 
-var errMapManyDestination = fmt.Errorf("destination must be a pointer of slice of struct")
+var errMapManyDestination = xerrors.Errorf("destination must be a pointer of slice of struct")
 
 // MapRows reads all data from rows and maps those columns for each destination struct.
 // pointerOfSliceOfStruct MUST BE a pointer of slice of pointer of struct.
@@ -181,7 +182,7 @@ func aggregateFields(dest *reflect.Value) (map[string]int, error) {
 		tag := f.Tag.Get("exql")
 		if tag != "" {
 			if f.Type.Kind() == reflect.Ptr {
-				return nil, fmt.Errorf("struct field must not be a pointer: %s %s", f.Type.Name(), f.Type.Kind())
+				return nil, xerrors.Errorf("struct field must not be a pointer: %s %s", f.Type.Name(), f.Type.Kind())
 			}
 			tags, err := ParseTags(tag)
 			if err != nil {
@@ -194,13 +195,13 @@ func aggregateFields(dest *reflect.Value) (map[string]int, error) {
 	return fields, nil
 }
 
-var errMapRowSerialDestination = fmt.Errorf("destination must be either *(struct) or *((*struct)(nil))")
+var errMapRowSerialDestination = xerrors.Errorf("destination must be either *(struct) or *((*struct)(nil))")
 
 func (s *serialMapper) Map(rows *sql.Rows, dest ...interface{}) error {
 	var values []*reflect.Value
 
 	if len(dest) == 0 {
-		return fmt.Errorf("empty dest list")
+		return xerrors.Errorf("empty dest list")
 	}
 
 	for _, model := range dest {
@@ -251,7 +252,7 @@ func mapRowSerial(
 		headCol := cols[colIndex]
 		expectedHeadCol := headColProvider(destIndex)
 		if headCol.Name() != expectedHeadCol {
-			return fmt.Errorf(
+			return xerrors.Errorf(
 				"head col mismatch: expected=%s, actual=%s",
 				expectedHeadCol, headCol.Name(),
 			)

parser.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"github.com/iancoleman/strcase"
+	"golang.org/x/xerrors"
 )
 
 type parser struct{}
@@ -249,5 +250,5 @@ func ParseType(t string, nullable bool) (string, error) {
 		}
 		return jsonType, nil
 	}
-	return "", fmt.Errorf("unknown type: %s", t)
+	return "", xerrors.Errorf("unknown type: %s", t)
 }

query.go

@@ -2,10 +2,10 @@ package exql
 
 import (
 	"errors"
-	"fmt"
 	"reflect"
 
 	q "github.com/loilo-inc/exql/v2/query"
+	"golang.org/x/xerrors"
 )
 
 func Where(str string, args ...any) q.Condition {
@@ -57,12 +57,12 @@ func QueryForBulkInsert[T Model](modelPtrs ...T) (q.Query, error) {
 
 func AggregateModelMetadata(modelPtr Model) (*ModelMetadata, error) {
 	if modelPtr == nil {
-		return nil, fmt.Errorf("pointer is nil")
+		return nil, xerrors.Errorf("pointer is nil")
 	}
 	objValue := reflect.ValueOf(modelPtr)
 	objType := objValue.Type()
 	if objType.Kind() != reflect.Ptr || objType.Elem().Kind() != reflect.Struct {
-		return nil, fmt.Errorf("object must be pointer of struct")
+		return nil, xerrors.Errorf("object must be pointer of struct")
 	}
 	data := map[string]any{}
 	// *User -> User
@@ -80,7 +80,7 @@ func AggregateModelMetadata(modelPtr Model) (*ModelMetadata, error) {
 			}
 			colName, ok := tags["column"]
 			if !ok || colName == "" {
-				return nil, fmt.Errorf("column tag is not set")
+				return nil, xerrors.Errorf("column tag is not set")
 			}
 			exqlTagCount++
 			if _, primary := tags["primary"]; primary {
@@ -98,16 +98,16 @@ func AggregateModelMetadata(modelPtr Model) (*ModelMetadata, error) {
 		}
 	}
 	if exqlTagCount == 0 {
-		return nil, fmt.Errorf("obj doesn't have exql tags in any fields")
+		return nil, xerrors.Errorf("obj doesn't have exql tags in any fields")
 	}
 
 	if len(primaryKeyColumns) == 0 {
-		return nil, fmt.Errorf("table has no primary key")
+		return nil, xerrors.Errorf("table has no primary key")
 	}
 
 	tableName := modelPtr.TableName()
 	if tableName == "" {
-		return nil, fmt.Errorf("empty table name")
+		return nil, xerrors.Errorf("empty table name")
 	}
 	return &ModelMetadata{
 		TableName:          tableName,
@@ -123,17 +123,17 @@ func QueryForUpdateModel(
 	where q.Condition,
 ) (q.Query, error) {
 	if updateStructPtr == nil {
-		return nil, fmt.Errorf("pointer is nil")
+		return nil, xerrors.Errorf("pointer is nil")
 	}
 	objValue := reflect.ValueOf(updateStructPtr)
 	objType := objValue.Type()
 	if objType.Kind() != reflect.Ptr || objType.Elem().Kind() != reflect.Struct {
-		return nil, fmt.Errorf("must be pointer of struct")
+		return nil, xerrors.Errorf("must be pointer of struct")
 	}
 	objType = objType.Elem()
 	values := make(map[string]any)
 	if objType.NumField() == 0 {
-		return nil, fmt.Errorf("struct has no field")
+		return nil, xerrors.Errorf("struct has no field")
 	}
 
 	for i := 0; i < objType.NumField(); i++ {
@@ -146,25 +146,25 @@ func QueryForUpdateModel(
 		if tags, err := ParseTags(tag); err != nil {
 			return nil, err
 		} else if col, ok := tags["column"]; !ok {
-			return nil, fmt.Errorf("tag must include column")
+			return nil, xerrors.Errorf("tag must include column")
 		} else {
 			colName = col
 		}
 		if f.Type.Kind() != reflect.Ptr {
-			return nil, fmt.Errorf("field must be pointer")
+			return nil, xerrors.Errorf("field must be pointer")
 		}
 		fieldValue := objValue.Elem().Field(i)
 		if !fieldValue.IsNil() {
 			values[colName] = fieldValue.Elem().Interface()
 		}
 	}
 	if len(values) == 0 {
-		return nil, fmt.Errorf("no value for update")
+		return nil, xerrors.Errorf("no value for update")
 	}
 
 	tableName := updateStructPtr.UpdateTableName()
 	if tableName == "" {
-		return nil, fmt.Errorf("empty table name")
+		return nil, xerrors.Errorf("empty table name")
 	}
 	b := q.NewBuilder()
 	b.Sprintf("UPDATE `%s`", tableName)

query/query.go

@@ -2,9 +2,10 @@
 package query
 
 import (
-	"fmt"
 	"regexp"
 	"strings"
+
+	"golang.org/x/xerrors"
 )
 
 type Query interface {
@@ -37,15 +38,15 @@ func (f *query) Query() (sqlStmt string, sqlArgs []any, resErr error) {
 			break
 		}
 		if argIdx == len(args) {
-			resErr = fmt.Errorf("missing argument at %d", argIdx)
+			resErr = xerrors.Errorf("missing argument at %d", argIdx)
 			return
 		}
 		mStart := match[0]
 		mEnd := match[1]
 		if mEnd-mStart == 2 {
 			// :?
 			if q, ok := args[argIdx].(Query); !ok {
-				resErr = fmt.Errorf("unexpected argument type for :? placeholder at %d", argIdx)
+				resErr = xerrors.Errorf("unexpected argument type for :? placeholder at %d", argIdx)
 				return
 			} else if stmt, vals, err := q.Query(); err != nil {
 				resErr = err
@@ -65,7 +66,7 @@ func (f *query) Query() (sqlStmt string, sqlArgs []any, resErr error) {
 		argIdx += 1
 	}
 	if len(args) != argIdx {
-		resErr = fmt.Errorf("arguments count mismatch: found %d, got %d", argIdx, len(args))
+		resErr = xerrors.Errorf("arguments count mismatch: found %d, got %d", argIdx, len(args))
 		return
 	}
 	if len(str) > 0 {
@@ -187,7 +188,7 @@ func Q(q string, args ...any) Query {
 //	Cols("users.*") // `users`.*
 func Cols(cols ...string) Query {
 	if len(cols) == 0 {
-		return errQuery(fmt.Errorf("empty columns"))
+		return errQuery(xerrors.Errorf("empty columns"))
 	}
 	return &query{
 		query: QuoteColumns(cols...),
@@ -219,7 +220,7 @@ func V(a ...any) Query {
 // Vals is another form of V that accepts a slice in generic type.
 func Vals[T any](vals []T) Query {
 	if len(vals) == 0 {
-		return errQuery(fmt.Errorf("empty values"))
+		return errQuery(xerrors.Errorf("empty values"))
 	}
 	var args []any
 	for _, v := range vals {
@@ -242,7 +243,7 @@ func Vals[T any](vals []T) Query {
 //	db.DB().Exec("update users set age = ?, name = ? where id = ?", 20, "go", 1)
 func Set(m map[string]any) Query {
 	if len(m) == 0 {
-		return errQuery(fmt.Errorf("empty values for set clause"))
+		return errQuery(xerrors.Errorf("empty values for set clause"))
 	}
 	b := NewBuilder()
 	it := NewKeyIterator(m)

tag.go

@@ -1,8 +1,9 @@
 package exql
 
 import (
-	"fmt"
 	"strings"
+
+	"golang.org/x/xerrors"
 )
 
 func ParseTags(tag string) (map[string]string, error) {
@@ -13,7 +14,7 @@ func ParseTags(tag string) (map[string]string, error) {
 			return nil
 		}
 		if _, ok := ret[k]; ok {
-			return fmt.Errorf("duplicated tag: %s", k)
+			return xerrors.Errorf("duplicated tag: %s", k)
 		}
 		ret[k] = v
 		return nil
@@ -29,11 +30,11 @@ func ParseTags(tag string) (map[string]string, error) {
 				return nil, err
 			}
 		} else {
-			return nil, fmt.Errorf("invalid tag format")
+			return nil, xerrors.Errorf("invalid tag format")
 		}
 	}
 	if len(ret) == 0 {
-		return nil, fmt.Errorf("invalid tag format")
+		return nil, xerrors.Errorf("invalid tag format")
 	}
 	return ret, nil
 }

tx.go

@@ -3,9 +3,9 @@ package exql
 import (
 	"context"
 	"database/sql"
-	"fmt"
 
 	"github.com/loilo-inc/exql/v2/query"
+	"golang.org/x/xerrors"
 )
 
 type Tx interface {
@@ -129,7 +129,7 @@ func Transaction(db *sql.DB, ctx context.Context, opts *sql.TxOptions, callback
 		return callback(tx)
 	}()
 	if p != nil {
-		txErr = fmt.Errorf("recovered: %s", p)
+		txErr = xerrors.Errorf("recovered: %s", p)
 	}
 	if txErr != nil {
 		if err := sqlTx.Rollback(); err != nil {