Make store testable

Store driver name is now a parameter on Store class. It make possible
to test some aspects of store class. Also, unit tests included.

main.go

@@ -41,8 +41,16 @@ func init() {
 }
 
 func main() {
-	store := store.New()
-	defer store.Close() // Without gin graceful stop it is not really working
+	driver := os.Getenv("STORAGE_DRIVER")
+	if driver == "" {
+		driver = "memory"
+	}
+
+	store, err := store.New(driver)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer store.Close()
 
 	r := gin.Default()
 	r.GET("/:hash", func(c *gin.Context) {

pkg/store/store.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"log"
 	"os"
+	"time"
 
 	"github.com/teris-io/shortid"
 )
@@ -20,10 +21,16 @@ type storeDriver interface {
 
 var drivers = make(map[string]storeDriver)
 
+type storeData struct {
+	URL       string    `json:"url" binding:"required"`
+	CreatedAt time.Time `json:"createdAt" binding:"required"`
+}
+
 // Store is the database storage driver.
 type Store struct {
-	driver    storeDriver
-	AuthToken string
+	driver     storeDriver
+	driverName string
+	AuthToken  string
 }
 
 // Register makes a store driver available by the provided name.
@@ -32,22 +39,29 @@ func Register(name string, driver storeDriver) {
 }
 
 // New creates a new instance of Store object
-func New() *Store {
-	s := new(Store)
-	s.AuthToken = os.Getenv("AUTHORIZATION_TOKEN")
-
-	// Get storage driver or use firestore as default.
-	name := os.Getenv("STORAGE_DRIVER")
-	if name == "" {
-		name = "memory"
+func New(driverName string) (*Store, error) {
+	if driverName == "" {
+		return nil, errors.New("Driver name cannot be empty. Use .Default method instead")
+	}
+
+	driver, exists := drivers[driverName]
+	if !exists {
+		return nil, errors.New("Driver does not exists")
 	}
-	log.Printf("Storage driver: %s", name)
 
-	// Initialize storage driver.
-	s.driver = drivers[name]
+	s := &Store{
+		driver:     driver,
+		driverName: driverName,
+		AuthToken:  os.Getenv("AUTHORIZATION_TOKEN"),
+	}
 	s.driver.init()
 
-	return s
+	return s, nil
+}
+
+// Default ...
+func Default() (*Store, error) {
+	return New("memory")
 }
 
 // Close cleanup driver connection

pkg/store/store_test.go

@@ -0,0 +1,33 @@
+package store
+
+import "testing"
+
+func TestStoreEmptyDriver(t *testing.T) {
+	exp := "Driver name cannot be empty. Use .Default method instead"
+	_, err := New("")
+
+	if err.Error() != exp {
+		t.Errorf("Expected error \"%v\" and got \"%v\".", exp, err)
+	}
+}
+
+func TestStoreInvalidDriver(t *testing.T) {
+	exp := "Driver does not exists"
+	_, err := New("nonono")
+
+	if err.Error() != exp {
+		t.Errorf("Expected error \"%v\" and got \"%v\".", exp, err)
+	}
+}
+
+func TestStoreDefaultDriver(t *testing.T) {
+	exp := "memory"
+	store, err := Default()
+	if err != nil {
+		t.Errorf("Error \"%v\".", err)
+	}
+	if store.driverName != exp {
+		t.Errorf("Expected driver \"%v\" and got \"%v\".", exp, store.driverName)
+	}
+	defer store.Close()
+}