show snapshot of lazygit when test fails for easier investigation

pkg/gui/gui_driver.go

@@ -50,10 +50,18 @@ func (self *GuiDriver) CurrentContext() types.Context {
 }
 
 func (self *GuiDriver) Fail(message string) {
+	currentView := self.gui.g.CurrentView()
+	fullMessage := fmt.Sprintf(
+		"%s\nFinal Lazygit state:\n%s\nUpon failure, focused view was '%s'.\nLog:\n%s", message,
+		self.gui.g.Snapshot(),
+		currentView.Name(),
+		strings.Join(self.gui.CmdLog, "\n"),
+	)
+
 	self.gui.g.Close()
 	// need to give the gui time to close
 	time.Sleep(time.Millisecond * 100)
-	panic(fmt.Sprintf("%s\nLog:\n%s", message, strings.Join(self.gui.CmdLog, "\n")))
+	panic(fullMessage)
 }
 
 // logs to the normal place that you log to i.e. viewable with `lazygit --logs`