From 081a694b0af16f86d406ac2832433a98a6fa625a Mon Sep 17 00:00:00 2001
From: gedi <gediminas.morkevicius@gmail.com>
Date: Thu, 10 Sep 2015 21:31:35 +0300
Subject: [PATCH] closes #24

---
 .travis.yml    |  6 ++++--
 driver.go      | 34 ++++++++++++++++++++++++++++------
 driver_test.go | 33 +++++++++++++++++++++++++++++++++
 sqlmock.go     |  9 +++++++++
 4 files changed, 74 insertions(+), 8 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 8d7ddf0..72323d1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,9 +4,11 @@ go:
   - 1.2
   - 1.3
   - 1.4
+  - 1.5
   - release
   - tip
 
 script:
-  - go test -v ./...
-  - go test -race ./...
+  - go get -t
+  - go test -v
+  - go test -race
diff --git a/driver.go b/driver.go
index 54eb012..2a480fe 100644
--- a/driver.go
+++ b/driver.go
@@ -39,7 +39,7 @@ func (d *mockDriver) Open(dsn string) (driver.Conn, error) {
 // and a mock to manage expectations.
 // Pings db so that all expectations could be
 // asserted.
-func New() (db *sql.DB, mock Sqlmock, err error) {
+func New() (*sql.DB, Sqlmock, error) {
 	pool.Lock()
 	dsn := fmt.Sprintf("sqlmock_db_%d", pool.counter)
 	pool.counter++
@@ -48,9 +48,31 @@ func New() (db *sql.DB, mock Sqlmock, err error) {
 	pool.conns[dsn] = smock
 	pool.Unlock()
 
-	db, err = sql.Open("sqlmock", dsn)
-	if err != nil {
-		return
-	}
-	return db, smock, db.Ping()
+	return smock.open()
+}
+
+// NewWithDSN creates sqlmock database connection
+// with a specific DSN and a mock to manage expectations.
+// Pings db so that all expectations could be asserted.
+//
+// This method is introduced because of sql abstraction
+// libraries, which do not provide a way to initialize
+// with sql.DB instance. For example GORM library.
+//
+// Note, it will error if attempted to create with an
+// already used dsn
+//
+// It is not recommended to use this method, unless you
+// really need it and there is no other way around.
+func NewWithDSN(dsn string) (*sql.DB, Sqlmock, error) {
+	pool.Lock()
+	if _, ok := pool.conns[dsn]; ok {
+		pool.Unlock()
+		return nil, nil, fmt.Errorf("cannot create a new mock database with the same dsn: %s", dsn)
+	}
+	smock := &sqlmock{dsn: dsn, drv: pool, ordered: true}
+	pool.conns[dsn] = smock
+	pool.Unlock()
+
+	return smock.open()
 }
diff --git a/driver_test.go b/driver_test.go
index aa60f12..407b619 100644
--- a/driver_test.go
+++ b/driver_test.go
@@ -3,8 +3,14 @@ package sqlmock
 import (
 	"fmt"
 	"testing"
+
+	"github.com/jinzhu/gorm"
 )
 
+type void struct{}
+
+func (void) Print(...interface{}) {}
+
 func ExampleNew() {
 	db, mock, err := New()
 	if err != nil {
@@ -16,6 +22,33 @@ func ExampleNew() {
 	mock.ExpectBegin().WillReturnError(fmt.Errorf("an error will occur on db.Begin() call"))
 }
 
+func ExampleNewWithDSN() {
+	_, mock, err := NewWithDSN("mydsn for gorm")
+	if err != nil {
+		fmt.Println("expected no error, but got:", err)
+		return
+	}
+	// use the same dsn to initialize a connection
+	db, err := gorm.Open("sqlmock", "mydsn for gorm")
+	if err != nil {
+		fmt.Println("expected no error from gorm, but got:", err)
+		return
+	}
+	defer db.Close()
+	db.SetLogger(void{}) // sad - nil panics
+
+	// now we can expect operations performed on db
+	mock.ExpectBegin().WillReturnError(fmt.Errorf("an error will occur on db.Begin() call"))
+
+	txconn := db.Begin()
+	for _, err := range txconn.GetErrors() {
+		fmt.Println(err.Error())
+	}
+
+	// Output: `sqlmock` is not officially supported, running under compatibility mode.
+	// an error will occur on db.Begin() call
+}
+
 func TestShouldOpenConnectionIssue15(t *testing.T) {
 	db, mock, err := New()
 	if err != nil {
diff --git a/sqlmock.go b/sqlmock.go
index 09a0bf9..1fbe8b4 100644
--- a/sqlmock.go
+++ b/sqlmock.go
@@ -12,6 +12,7 @@ are also supported.
 package sqlmock
 
 import (
+	"database/sql"
 	"database/sql/driver"
 	"fmt"
 	"reflect"
@@ -79,6 +80,14 @@ type sqlmock struct {
 	expected []expectation
 }
 
+func (s *sqlmock) open() (*sql.DB, Sqlmock, error) {
+	db, err := sql.Open("sqlmock", s.dsn)
+	if err != nil {
+		return db, s, err
+	}
+	return db, s, db.Ping()
+}
+
 func (c *sqlmock) ExpectClose() *ExpectedClose {
 	e := &ExpectedClose{}
 	c.expected = append(c.expected, e)