Mono repo -> Master (#22553)

Combines the following repositories into one:

https://github.com/mattermost/mattermost-server
https://github.com/mattermost/mattermost-webapp
https://github.com/mattermost/focalboard
https://github.com/mattermost/mattermost-plugin-playbooks

server/channels/store/storetest/utils_test.go

@@ -0,0 +1,21 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package storetest
+
+import (
+	"regexp"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestNewTestId(t *testing.T) {
+	rg := regexp.MustCompile(`(\S\d){13}`)
+
+	for i := 0; i < 1000; i++ {
+		id := NewTestId()
+		require.LessOrEqual(t, len(id), 26, "test ids shouldn't be longer than 26 chars")
+		require.Regexp(t, rg, id, "test ids should have pattern e.g a1b2c3...")
+	}
+}