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/app/email/notification_email_test.go

@@ -0,0 +1,73 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package email
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/mattermost/mattermost-server/v6/model"
+)
+
+func TestProcessMessageAttachments(t *testing.T) {
+	th := Setup(t).InitBasic()
+	defer th.TearDown()
+
+	post := &model.Post{
+		Message: "This is the message",
+	}
+
+	messageAttachments := []*model.SlackAttachment{
+		{
+			Color:      "#FF0000",
+			Pretext:    "message attachment 1 pretext",
+			AuthorName: "author name",
+			AuthorLink: "https://example.com/slack_attachment_1/author_link",
+			AuthorIcon: "https://example.com/slack_attachment_1/author_icon",
+			Title:      "message attachment 1 title",
+			TitleLink:  "https://example.com/slack_attachment_1/title_link",
+			Text:       "message attachment 1 text",
+			ImageURL:   "https://example.com/slack_attachment_1/image",
+			ThumbURL:   "https://example.com/slack_attachment_1/thumb",
+			Fields: []*model.SlackAttachmentField{
+				{
+					Short: true,
+					Title: "message attachment 1 field 1 title",
+					Value: "message attachment 1 field 1 value",
+				},
+				{
+					Short: false,
+					Title: "message attachment 1 field 2 title",
+					Value: "message attachment 1 field 2 value",
+				},
+				{
+					Short: true,
+					Title: "message attachment 1 field 3 title",
+					Value: "message attachment 1 field 3 value",
+				},
+				{
+					Short: true,
+					Title: "message attachment 1 field 4 title",
+					Value: "message attachment 1 field 4 value",
+				},
+			},
+		},
+		{
+			Color:      "#FF0000",
+			Pretext:    "message attachment 2 pretext",
+			AuthorName: "author name 2",
+			Text:       "message attachment 2 text",
+		},
+	}
+
+	model.ParseSlackAttachment(post, messageAttachments)
+
+	processedAttachmentsPost := ProcessMessageAttachments(post, "https://example.com")
+	require.NotNil(t, processedAttachmentsPost)
+	require.Len(t, processedAttachmentsPost, 2)
+	require.Equal(t, processedAttachmentsPost[0].Color, "#FF0000")
+	require.Equal(t, processedAttachmentsPost[0].FieldRows[0].Cells[0].Title, "message attachment 1 field 1 title")
+	require.Equal(t, processedAttachmentsPost[1].Color, "#FF0000")
+}