PLT-7824 Added support for mentions with <@userid> and <!here> (#7615) (#7737)

9 files changed, 170 insertions, 123 deletions

diff --git a/app/command.go b/app/command.go
index 96dd2656c..8bd025c8e 100644
--- a/app/command.go
+++ b/app/command.go
@@ -275,6 +275,10 @@ func (a *App) HandleCommandResponse(command *model.Command, args *model.CommandA
 		}
 	}
 
+	// Process Slack text replacements
+	response.Text = a.ProcessSlackText(response.Text)
+	response.Attachments = a.ProcessSlackAttachments(response.Attachments)
+
 	if _, err := a.CreateCommandPost(post, args.TeamId, response); err != nil {
 		l4g.Error(err.Error())
 	}
diff --git a/app/slack.go b/app/slack.go
new file mode 100644
index 000000000..f05c27478
--- /dev/null
+++ b/app/slack.go
@@ -0,0 +1,76 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package app
+
+import (
+	"regexp"
+
+	"fmt"
+	"strings"
+
+	"github.com/mattermost/mattermost-server/model"
+	"github.com/mattermost/mattermost-server/store"
+)
+
+func (a *App) ProcessSlackText(text string) string {
+	text = expandAnnouncement(text)
+	text = replaceUserIds(a.Srv.Store.User(), text)
+
+	return text
+}
+
+// Expand announcements in incoming webhooks from Slack. Those announcements
+// can be found in the text attribute, or in the pretext, text, title and value
+// attributes of the attachment structure. The Slack attachment structure is
+// documented here: https://api.slack.com/docs/attachments
+func (app *App) ProcessSlackAttachments(a []*model.SlackAttachment) []*model.SlackAttachment {
+	var nonNilAttachments = model.StringifySlackFieldValue(a)
+	for _, attachment := range a {
+		attachment.Pretext = app.ProcessSlackText(attachment.Pretext)
+		attachment.Text = app.ProcessSlackText(attachment.Text)
+		attachment.Title = app.ProcessSlackText(attachment.Title)
+
+		for _, field := range attachment.Fields {
+			if field.Value != nil {
+				// Ensure the value is set to a string if it is set
+				field.Value = app.ProcessSlackText(fmt.Sprintf("%v", field.Value))
+			}
+		}
+	}
+	return nonNilAttachments
+}
+
+// To mention @channel or @here via a webhook in Slack, the message should contain
+// <!channel> or <!here>, as explained at the bottom of this article:
+// https://get.slack.help/hc/en-us/articles/202009646-Making-announcements
+func expandAnnouncement(text string) string {
+	a1 := [3]string{"<!channel>", "<!here>", "<!all>"}
+	a2 := [3]string{"@channel", "@here", "@all"}
+
+	for i, a := range a1 {
+		text = strings.Replace(text, a, a2[i], -1)
+	}
+	return text
+}
+
+// Replaces user IDs mentioned like this <@userID> to a normal username (eg. @bob)
+// This is required so that Mattermost maintains Slack compatibility
+// Refer to: https://api.slack.com/changelog/2017-09-the-one-about-usernames
+func replaceUserIds(userStore store.UserStore, text string) string {
+	rgx, err := regexp.Compile("<@([a-zA-Z0-9]+)>")
+	if err == nil {
+		userIds := make([]string, 0)
+		matches := rgx.FindAllStringSubmatch(text, -1)
+		for _, match := range matches {
+			userIds = append(userIds, match[1])
+		}
+
+		if res := <-userStore.GetProfileByIds(userIds, true); res.Err == nil {
+			for _, user := range res.Data.([]*model.User) {
+				text = strings.Replace(text, "<@"+user.Id+">", "@"+user.Username, -1)
+			}
+		}
+	}
+	return text
+}
diff --git a/app/slack_test.go b/app/slack_test.go
new file mode 100644
index 000000000..370942ba0
--- /dev/null
+++ b/app/slack_test.go
@@ -0,0 +1,83 @@
+package app
+
+import (
+	"testing"
+
+	"github.com/mattermost/mattermost-server/model"
+)
+
+func TestProcessSlackText(t *testing.T) {
+	th := Setup().InitBasic()
+	defer th.TearDown()
+
+	if th.App.ProcessSlackText("<!channel> foo <!channel>") != "@channel foo @channel" {
+		t.Fail()
+	}
+
+	if th.App.ProcessSlackText("<!here> bar <!here>") != "@here bar @here" {
+		t.Fail()
+	}
+
+	if th.App.ProcessSlackText("<!all> bar <!all>") != "@all bar @all" {
+		t.Fail()
+	}
+
+	userId := th.BasicUser.Id
+	username := th.BasicUser.Username
+	if th.App.ProcessSlackText("<@"+userId+"> hello") != "@"+username+" hello" {
+		t.Fail()
+	}
+}
+
+func TestProcessSlackAnnouncement(t *testing.T) {
+	th := Setup().InitBasic()
+	defer th.TearDown()
+
+	userId := th.BasicUser.Id
+	username := th.BasicUser.Username
+
+	attachments := []*model.SlackAttachment{
+		{
+			Pretext: "<!channel> pretext <!here>",
+			Text:    "<!channel> text <!here>",
+			Title:   "<!channel> title <!here>",
+			Fields: []*model.SlackAttachmentField{
+				{
+					Title: "foo",
+					Value: "<!channel> bar <!here>",
+					Short: true,
+				},
+			},
+		},
+		{
+			Pretext: "<@" + userId + "> pretext",
+			Text:    "<@" + userId + "> text",
+			Title:   "<@" + userId + "> title",
+			Fields: []*model.SlackAttachmentField{
+				{
+					Title: "foo",
+					Value: "<@" + userId + "> bar",
+					Short: true,
+				},
+			},
+		},
+	}
+	attachments = th.App.ProcessSlackAttachments(attachments)
+	if len(attachments) != 2 || len(attachments[0].Fields) != 1 || len(attachments[1].Fields) != 1 {
+		t.Fail()
+	}
+
+	if attachments[0].Pretext != "@channel pretext @here" ||
+		attachments[0].Text != "@channel text @here" ||
+		attachments[0].Title != "@channel title @here" ||
+		attachments[0].Fields[0].Value != "@channel bar @here" {
+		t.Fail()
+	}
+
+	if attachments[1].Pretext != "@"+username+" pretext" ||
+		attachments[1].Text != "@"+username+" text" ||
+		attachments[1].Title != "@"+username+" title" ||
+		attachments[1].Fields[0].Value != "@"+username+" bar" {
+		t.Fail()
+	}
+}
diff --git a/app/webhook.go b/app/webhook.go
index f7efd3af0..5ce56aa88 100644
--- a/app/webhook.go
+++ b/app/webhook.go
@@ -537,6 +537,9 @@ func (a *App) HandleIncomingWebhook(hookId string, req *model.IncomingWebhookReq
 	channelName := req.ChannelName
 	webhookType := req.Type
 
+	text = a.ProcessSlackText(text)
+	req.Attachments = a.ProcessSlackAttachments(req.Attachments)
+
 	// attachments is in here for slack compatibility
 	if len(req.Attachments) > 0 {
 		if len(req.Props) == 0 {
diff --git a/model/command_response.go b/model/command_response.go
index f5c628b71..a3a171ce4 100644
--- a/model/command_response.go
+++ b/model/command_response.go
@@ -59,8 +59,7 @@ func CommandResponseFromJson(data io.Reader) *CommandResponse {
 		return nil
 	}
 
-	o.Text = ExpandAnnouncement(o.Text)
-	o.Attachments = ProcessSlackAttachments(o.Attachments)
+	o.Attachments = StringifySlackFieldValue(o.Attachments)
 
 	return &o
 }
diff --git a/model/incoming_webhook.go b/model/incoming_webhook.go
index e8ed6dc82..e9468e87b 100644
--- a/model/incoming_webhook.go
+++ b/model/incoming_webhook.go
@@ -208,8 +208,7 @@ func IncomingWebhookRequestFromJson(data io.Reader) (*IncomingWebhookRequest, *A
 		}
 	}
 
-	o.Text = ExpandAnnouncement(o.Text)
-	o.Attachments = ProcessSlackAttachments(o.Attachments)
+	o.Attachments = StringifySlackFieldValue(o.Attachments)
 
 	return o, nil
 }
diff --git a/model/incoming_webhook_test.go b/model/incoming_webhook_test.go
index a716432f2..5b78f877f 100644
--- a/model/incoming_webhook_test.go
+++ b/model/incoming_webhook_test.go
@@ -101,64 +101,6 @@ func TestIncomingWebhookPreUpdate(t *testing.T) {
 	o.PreUpdate()
 }
 
-func TestIncomingWebhookRequestFromJson_Announcements(t *testing.T) {
-	text := "This message will send a notification to all team members in the channel where you post the message, because it contains: <!channel>"
-	expected := "This message will send a notification to all team members in the channel where you post the message, because it contains: @channel"
-
-	// simple payload
-	payload := `{"text": "` + text + `"}`
-	data := strings.NewReader(payload)
-	iwr, _ := IncomingWebhookRequestFromJson(data)
-
-	if iwr == nil {
-		t.Fatal("IncomingWebhookRequest should not be nil")
-	}
-	if iwr.Text != expected {
-		t.Fatalf("Sample text should be: %s, got: %s", expected, iwr.Text)
-	}
-
-	// payload with attachment (pretext, title, text, value)
-	payload = `{
-			"attachments": [
-				{
-					"pretext": "` + text + `",
-					"title": "` + text + `",
-					"text": "` + text + `",
-					"fields": [
-						{
-							"title": "A title",
-							"value": "` + text + `",
-							"short": false
-						}
-					]
-				}
-			]
-		}`
-
-	data = strings.NewReader(payload)
-	iwr, _ = IncomingWebhookRequestFromJson(data)
-
-	if iwr == nil {
-		t.Fatal("IncomingWebhookRequest should not be nil")
-	}
-
-	attachment := iwr.Attachments[0]
-	if attachment.Pretext != expected {
-		t.Fatalf("Sample attachment pretext should be:%s, got: %s", expected, attachment.Pretext)
-	}
-	if attachment.Text != expected {
-		t.Fatalf("Sample attachment text should be: %s, got: %s", expected, attachment.Text)
-	}
-	if attachment.Title != expected {
-		t.Fatalf("Sample attachment title should be: %s, got: %s", expected, attachment.Title)
-	}
-
-	field := attachment.Fields[0]
-	if field.Value != expected {
-		t.Fatalf("Sample attachment field value should be: %s, got: %s", expected, field.Value)
-	}
-}
-
 func TestIncomingWebhookRequestFromJson(t *testing.T) {
 	texts := []string{
 		`this is a test`,
diff --git a/model/slack_attachment.go b/model/slack_attachment.go
index fe3958316..197d3f0f9 100644
--- a/model/slack_attachment.go
+++ b/model/slack_attachment.go
@@ -5,7 +5,6 @@ package model
 
 import (
 	"fmt"
-	"strings"
 )
 
 type SlackAttachment struct {
@@ -34,23 +33,7 @@ type SlackAttachmentField struct {
 	Short bool        `json:"short"`
 }
 
-// To mention @channel via a webhook in Slack, the message should contain
-// <!channel>, as explained at the bottom of this article:
-// https://get.slack.help/hc/en-us/articles/202009646-Making-announcements
-func ExpandAnnouncement(text string) string {
-	c1 := "<!channel>"
-	c2 := "@channel"
-	if strings.Contains(text, c1) {
-		return strings.Replace(text, c1, c2, -1)
-	}
-	return text
-}
-
-// Expand announcements in incoming webhooks from Slack. Those announcements
-// can be found in the text attribute, or in the pretext, text, title and value
-// attributes of the attachment structure. The Slack attachment structure is
-// documented here: https://api.slack.com/docs/attachments
-func ProcessSlackAttachments(a []*SlackAttachment) []*SlackAttachment {
+func StringifySlackFieldValue(a []*SlackAttachment) []*SlackAttachment {
 	var nonNilAttachments []*SlackAttachment
 	for _, attachment := range a {
 		if attachment == nil {
@@ -58,10 +41,6 @@ func ProcessSlackAttachments(a []*SlackAttachment) []*SlackAttachment {
 		}
 		nonNilAttachments = append(nonNilAttachments, attachment)
 
-		attachment.Pretext = ExpandAnnouncement(attachment.Pretext)
-		attachment.Text = ExpandAnnouncement(attachment.Text)
-		attachment.Title = ExpandAnnouncement(attachment.Title)
-
 		var nonNilFields []*SlackAttachmentField
 		for _, field := range attachment.Fields {
 			if field == nil {
@@ -71,7 +50,7 @@ func ProcessSlackAttachments(a []*SlackAttachment) []*SlackAttachment {
 
 			if field.Value != nil {
 				// Ensure the value is set to a string if it is set
-				field.Value = ExpandAnnouncement(fmt.Sprintf("%v", field.Value))
+				field.Value = fmt.Sprintf("%v", field.Value)
 			}
 		}
 		attachment.Fields = nonNilFields
diff --git a/model/slack_attachment_test.go b/model/slack_attachment_test.go
deleted file mode 100644
index 2ba32baf2..000000000
--- a/model/slack_attachment_test.go
+++ /dev/null
@@ -1,38 +0,0 @@
-package model
-
-import (
-	"testing"
-)
-
-func TestExpandAnnouncement(t *testing.T) {
-	if ExpandAnnouncement("<!channel> foo <!channel>") != "@channel foo @channel" {
-		t.Fail()
-	}
-}
-
-func TestProcessSlackAnnouncement(t *testing.T) {
-	attachments := []*SlackAttachment{
-		{
-			Pretext: "<!channel> pretext",
-			Text:    "<!channel> text",
-			Title:   "<!channel> title",
-			Fields: []*SlackAttachmentField{
-				{
-					Title: "foo",
-					Value: "<!channel> bar",
-					Short: true,
-				}, nil,
-			},
-		}, nil,
-	}
-	attachments = ProcessSlackAttachments(attachments)
-	if len(attachments) != 1 || len(attachments[0].Fields) != 1 {
-		t.Fail()
-	}
-	if attachments[0].Pretext != "@channel pretext" ||
-		attachments[0].Text != "@channel text" ||
-		attachments[0].Title != "@channel title" ||
-		attachments[0].Fields[0].Value != "@channel bar" {
-		t.Fail()
-	}
-}