Update channel permissions for v4 endpoints (#5829)

* Fix join channel permission for v4 endpoint

* Allow regular users to get public channels they are not in

* Fix unit test

api4/channel_test.go

@@ -308,9 +308,24 @@ func TestGetChannel(t *testing.T) {
 		t.Fatal("ids did not match")
 	}
 
-	_, resp = Client.GetChannel(model.NewId(), "")
+	Client.RemoveUserFromChannel(th.BasicChannel.Id, th.BasicUser.Id)
+	_, resp = Client.GetChannel(th.BasicChannel.Id, "")
+	CheckNoError(t, resp)
+
+	channel, resp = Client.GetChannel(th.BasicPrivateChannel.Id, "")
+	CheckNoError(t, resp)
+
+	if channel.Id != th.BasicPrivateChannel.Id {
+		t.Fatal("ids did not match")
+	}
+
+	Client.RemoveUserFromChannel(th.BasicPrivateChannel.Id, th.BasicUser.Id)
+	_, resp = Client.GetChannel(th.BasicPrivateChannel.Id, "")
 	CheckForbiddenStatus(t, resp)
 
+	_, resp = Client.GetChannel(model.NewId(), "")
+	CheckNotFoundStatus(t, resp)
+
 	Client.Logout()
 	_, resp = Client.GetChannel(th.BasicChannel.Id, "")
 	CheckUnauthorizedStatus(t, resp)
@@ -323,6 +338,9 @@ func TestGetChannel(t *testing.T) {
 	_, resp = th.SystemAdminClient.GetChannel(th.BasicChannel.Id, "")
 	CheckNoError(t, resp)
 
+	_, resp = th.SystemAdminClient.GetChannel(th.BasicPrivateChannel.Id, "")
+	CheckNoError(t, resp)
+
 	_, resp = th.SystemAdminClient.GetChannel(th.BasicUser.Id, "")
 	CheckNotFoundStatus(t, resp)
 }
@@ -657,9 +675,27 @@ func TestGetChannelByName(t *testing.T) {
 		t.Fatal("names did not match")
 	}
 
+	channel, resp = Client.GetChannelByName(th.BasicPrivateChannel.Name, th.BasicTeam.Id, "")
+	CheckNoError(t, resp)
+
+	if channel.Name != th.BasicPrivateChannel.Name {
+		t.Fatal("names did not match")
+	}
+
+	Client.RemoveUserFromChannel(th.BasicChannel.Id, th.BasicUser.Id)
+	_, resp = Client.GetChannelByName(th.BasicChannel.Name, th.BasicTeam.Id, "")
+	CheckNoError(t, resp)
+
+	Client.RemoveUserFromChannel(th.BasicPrivateChannel.Id, th.BasicUser.Id)
+	_, resp = Client.GetChannelByName(th.BasicPrivateChannel.Name, th.BasicTeam.Id, "")
+	CheckForbiddenStatus(t, resp)
+
 	_, resp = Client.GetChannelByName(GenerateTestChannelName(), th.BasicTeam.Id, "")
 	CheckNotFoundStatus(t, resp)
 
+	_, resp = Client.GetChannelByName(GenerateTestChannelName(), "junk", "")
+	CheckBadRequestStatus(t, resp)
+
 	Client.Logout()
 	_, resp = Client.GetChannelByName(th.BasicChannel.Name, th.BasicTeam.Id, "")
 	CheckUnauthorizedStatus(t, resp)
@@ -861,8 +897,8 @@ func TestGetChannelMembersForUser(t *testing.T) {
 	members, resp := Client.GetChannelMembersForUser(th.BasicUser.Id, th.BasicTeam.Id, "")
 	CheckNoError(t, resp)
 
-	if len(*members) != 4 {
-		t.Fatal("should have 4 members on team")
+	if len(*members) != 5 {
+		t.Fatal("should have 5 members on team")
 	}
 
 	_, resp = Client.GetChannelMembersForUser("", th.BasicTeam.Id, "")
@@ -1149,6 +1185,10 @@ func TestAddChannelMember(t *testing.T) {
 		t.Fatal("should have returned exact user added to private channel")
 	}
 
+	Client.RemoveUserFromChannel(publicChannel.Id, user.Id)
+	_, resp = Client.AddChannelMember(publicChannel.Id, user.Id)
+	CheckNoError(t, resp)
+
 	cm, resp = Client.AddChannelMember(publicChannel.Id, "junk")
 	CheckBadRequestStatus(t, resp)
 
@@ -1227,6 +1267,9 @@ func TestRemoveChannelMember(t *testing.T) {
 	_, resp = Client.RemoveUserFromChannel(th.BasicChannel.Id, model.NewId())
 	CheckNotFoundStatus(t, resp)
 
+	_, resp = Client.RemoveUserFromChannel(model.NewId(), th.BasicUser2.Id)
+	CheckNotFoundStatus(t, resp)
+
 	th.LoginBasic2()
 	_, resp = Client.RemoveUserFromChannel(th.BasicChannel.Id, th.BasicUser.Id)
 	CheckForbiddenStatus(t, resp)
@@ -1248,6 +1291,10 @@ func TestRemoveChannelMember(t *testing.T) {
 	_, resp = Client.RemoveUserFromChannel(private.Id, th.BasicUser2.Id)
 	CheckNoError(t, resp)
 
+	th.LoginBasic2()
+	_, resp = Client.RemoveUserFromChannel(private.Id, th.BasicUser.Id)
+	CheckForbiddenStatus(t, resp)
+
 	_, resp = th.SystemAdminClient.RemoveUserFromChannel(private.Id, th.BasicUser.Id)
 	CheckNoError(t, resp)
 }