streamline driver code

driver/driver.go

@@ -2,7 +2,6 @@
 package driver
 
 import (
-	"errors"
 	"fmt"
 	neturl "net/url" // alias to allow `url string` func signature in New
 
@@ -14,6 +13,14 @@ import (
 	"github.com/mattes/migrate/file"
 )
 
+var driverMap = map[string]Driver{
+	"postgres":  &postgres.Driver{},
+	"mysql":     &mysql.Driver{},
+	"bash":      &bash.Driver{},
+	"cassandra": &cassandra.Driver{},
+	"sqlite3":   &sqlite3.Driver{},
+}
+
 // Driver is the interface type that needs to implemented by all drivers.
 type Driver interface {
 
@@ -47,48 +54,14 @@ func New(url string) (Driver, error) {
 		return nil, err
 	}
 
-	switch u.Scheme {
+	if d, found := driverMap[u.Scheme]; found {
-	case "postgres":
+		verifyFilenameExtension(u.Scheme, d)
-		d := &postgres.Driver{}
-		verifyFilenameExtension("postgres", d)
 		if err := d.Initialize(url); err != nil {
 			return nil, err
 		}
 		return d, nil
-
-	case "mysql":
-		d := &mysql.Driver{}
-		verifyFilenameExtension("mysql", d)
-		if err := d.Initialize(url); err != nil {
-			return nil, err
-		}
-		return d, nil
-
-	case "bash":
-		d := &bash.Driver{}
-		verifyFilenameExtension("bash", d)
-		if err := d.Initialize(url); err != nil {
-			return nil, err
-		}
-		return d, nil
-
-	case "cassandra":
-		d := &cassandra.Driver{}
-		verifyFilenameExtension("cassanda", d)
-		if err := d.Initialize(url); err != nil {
-			return nil, err
-		}
-		return d, nil
-	case "sqlite3":
-		d := &sqlite3.Driver{}
-		verifyFilenameExtension("sqlite3", d)
-		if err := d.Initialize(url); err != nil {
-			return nil, err
-		}
-		return d, nil
-	default:
-		return nil, errors.New(fmt.Sprintf("Driver '%s' not found.", u.Scheme))
 	}
+	return nil, fmt.Errorf("Driver '%s' not found.", u.Scheme)
 }
 
 // verifyFilenameExtension panics if the drivers filename extension

driver/driver_test.go

@@ -1,8 +1,6 @@
 package driver
 
-import (
+import "testing"
-	"testing"
-)
 
 func TestNew(t *testing.T) {
 	if _, err := New("unknown://url"); err == nil {