parallel tests (#7629)

app/options.go

@@ -4,25 +4,53 @@
 package app
 
 import (
+	"github.com/mattermost/mattermost-server/model"
 	"github.com/mattermost/mattermost-server/store"
 )
 
 type Option func(a *App)
 
+// By default, the app will use a global configuration file. This allows you to override all or part
+// of that configuration.
+//
+// The override parameter must be a *model.Config, func(*model.Config), or func(*model.Config) *model.Config.
+//
+// XXX: Most code will not respect this at the moment. (We need to eliminate utils.Cfg first.)
+func ConfigOverride(override interface{}) Option {
+	return func(a *App) {
+		switch o := override.(type) {
+		case *model.Config:
+			a.configOverride = func(*model.Config) *model.Config {
+				return o
+			}
+		case func(*model.Config):
+			a.configOverride = func(cfg *model.Config) *model.Config {
+				ret := *cfg
+				o(&ret)
+				return &ret
+			}
+		case func(*model.Config) *model.Config:
+			a.configOverride = o
+		default:
+			panic("invalid ConfigOverride")
+		}
+	}
+}
+
 // By default, the app will use the store specified by the configuration. This allows you to
 // construct an app with a different store.
 //
-// The storeOrFactory parameter must be either a store.Store or func(App) store.Store.
-func StoreOverride(storeOrFactory interface{}) Option {
+// The override parameter must be either a store.Store or func(App) store.Store.
+func StoreOverride(override interface{}) Option {
 	return func(a *App) {
-		switch s := storeOrFactory.(type) {
+		switch o := override.(type) {
 		case store.Store:
 			a.newStore = func() store.Store {
-				return s
+				return o
 			}
 		case func(*App) store.Store:
 			a.newStore = func() store.Store {
-				return s(a)
+				return o(a)
 			}
 		default:
 			panic("invalid StoreOverride")