[PLT-7362] Option to add user to channel if mentioned user is not currently in the channel (#7619)

* Option to add user to channel if mentioned user is not currently in the channel

* instead of link from server, just add component on client side to add channel member

* change implementation using post.props

* do clean up and add test

* sanitize post.props['add_channel_member'] on post creation

* move sanitize to app.CreatePost and also apply to app.UpdatePost

1 files changed, 77 insertions, 1 deletions

diff --git a/api4/post_test.go b/api4/post_test.go
index 3a410f2b4..05c5c3d97 100644
--- a/api4/post_test.go
+++ b/api4/post_test.go
@@ -24,7 +24,7 @@ func TestCreatePost(t *testing.T) {
 	defer th.TearDown()
 	Client := th.Client
 
-	post := &model.Post{ChannelId: th.BasicChannel.Id, Message: "#hashtag a" + model.NewId() + "a"}
+	post := &model.Post{ChannelId: th.BasicChannel.Id, Message: "#hashtag a" + model.NewId() + "a", Props: model.StringInterface{model.PROPS_ADD_CHANNEL_MEMBER: "no good"}}
 	rpost, resp := Client.CreatePost(post)
 	CheckNoError(t, resp)
 	CheckCreatedStatus(t, resp)
@@ -45,6 +45,10 @@ func TestCreatePost(t *testing.T) {
 		t.Fatal("newly created post shouldn't have EditAt set")
 	}
 
+	if rpost.Props[model.PROPS_ADD_CHANNEL_MEMBER] != nil {
+		t.Fatal("newly created post shouldn't have Props['add_channel_member'] set")
+	}
+
 	post.RootId = rpost.Id
 	post.ParentId = rpost.Id
 	_, resp = Client.CreatePost(post)
@@ -371,6 +375,73 @@ func TestCreatePostAll(t *testing.T) {
 	CheckForbiddenStatus(t, resp)
 }
 
+func TestCreatePostSendOutOfChannelMentions(t *testing.T) {
+	th := Setup().InitBasic().InitSystemAdmin()
+	defer th.TearDown()
+	Client := th.Client
+
+	WebSocketClient, err := th.CreateWebSocketClient()
+	if err != nil {
+		t.Fatal(err)
+	}
+	WebSocketClient.Listen()
+
+	inChannelUser := th.CreateUser()
+	th.LinkUserToTeam(inChannelUser, th.BasicTeam)
+	th.App.AddUserToChannel(inChannelUser, th.BasicChannel)
+
+	post1 := &model.Post{ChannelId: th.BasicChannel.Id, Message: "@" + inChannelUser.Username}
+	_, resp := Client.CreatePost(post1)
+	CheckNoError(t, resp)
+	CheckCreatedStatus(t, resp)
+
+	timeout := time.After(300 * time.Millisecond)
+	waiting := true
+	for waiting {
+		select {
+		case event := <-WebSocketClient.EventChannel:
+			if event.Event == model.WEBSOCKET_EVENT_EPHEMERAL_MESSAGE {
+				t.Fatal("should not have ephemeral message event")
+			}
+
+		case <-timeout:
+			waiting = false
+		}
+	}
+
+	outOfChannelUser := th.CreateUser()
+	th.LinkUserToTeam(outOfChannelUser, th.BasicTeam)
+
+	post2 := &model.Post{ChannelId: th.BasicChannel.Id, Message: "@" + outOfChannelUser.Username}
+	_, resp = Client.CreatePost(post2)
+	CheckNoError(t, resp)
+	CheckCreatedStatus(t, resp)
+
+	timeout = time.After(300 * time.Millisecond)
+	waiting = true
+	for waiting {
+		select {
+		case event := <-WebSocketClient.EventChannel:
+			if event.Event != model.WEBSOCKET_EVENT_EPHEMERAL_MESSAGE {
+				// Ignore any other events
+				continue
+			}
+
+			wpost := model.PostFromJson(strings.NewReader(event.Data["post"].(string)))
+			if acm, ok := wpost.Props[model.PROPS_ADD_CHANNEL_MEMBER].(map[string]interface{}); !ok {
+				t.Fatal("should have received ephemeral post with 'add_channel_member' in props")
+			} else {
+				if acm["post_id"] == nil || acm["user_ids"] == nil || acm["usernames"] == nil {
+					t.Fatal("should not be nil")
+				}
+			}
+			waiting = false
+		case <-timeout:
+			t.Fatal("timed out waiting for ephemeral message event")
+		}
+	}
+}
+
 func TestUpdatePost(t *testing.T) {
 	th := Setup().InitBasic().InitSystemAdmin()
 	defer th.TearDown()
@@ -421,6 +492,7 @@ func TestUpdatePost(t *testing.T) {
 
 	msg1 := "#hashtag a" + model.NewId() + " update post again"
 	rpost.Message = msg1
+	rpost.Props[model.PROPS_ADD_CHANNEL_MEMBER] = "no good"
 	rrupost, resp := Client.UpdatePost(rpost.Id, rpost)
 	CheckNoError(t, resp)
 
@@ -428,6 +500,10 @@ func TestUpdatePost(t *testing.T) {
 		t.Fatal("failed to updates")
 	}
 
+	if rrupost.Props[model.PROPS_ADD_CHANNEL_MEMBER] != nil {
+		t.Fatal("failed to sanitize Props['add_channel_member'], should be nil")
+	}
+
 	rpost2, err := th.App.CreatePost(&model.Post{ChannelId: channel.Id, Message: "zz" + model.NewId() + "a", Type: model.POST_JOIN_LEAVE, UserId: th.BasicUser.Id}, channel, false)
 	if err != nil {
 		t.Fatal(err)