bot,context: implement ProcessContext, NewContext

bot.go

@@ -266,10 +266,7 @@ func (b *Bot) NewMarkup() *ReplyMarkup {
 // NewContext returns a new native context object,
 // field by the passed update.
 func (b *Bot) NewContext(u Update) Context {
-	return &nativeContext{
-		b: b,
-		u: u,
-	}
+	return NewContext(b, u)
 }
 
 // Send accepts 2+ arguments, starting with destination chat, followed by

context.go

@@ -11,6 +11,15 @@ import (
 // used to handle actual endpoints.
 type HandlerFunc func(Context) error
 
+// NewContext returns a new native context object,
+// field by the passed update.
+func NewContext(b API, u Update) Context {
+	return &nativeContext{
+		b: b,
+		u: u,
+	}
+}
+
 // Context wraps an update and represents the context of current event.
 type Context interface {
 	// Bot returns the bot instance.

update.go

@@ -29,7 +29,13 @@ type Update struct {
 // ProcessUpdate processes a single incoming update.
 // A started bot calls this function automatically.
 func (b *Bot) ProcessUpdate(u Update) {
-	c := b.NewContext(u)
+	b.ProcessContext(b.NewContext(u))
+}
+
+// ProcessContext processes the given context.
+// A started bot calls this function automatically.
+func (b *Bot) ProcessContext(c Context) {
+	u := c.Update()
 
 	if u.Message != nil {
 		m := u.Message