PLT-7193: Regression - Custom slash commands don't work in direct or group message channels (#7635)

* No longer overriding specified team id for DMs/GMs, as these types of channels don't belong to a team, and doing so breaks slash commands for them

* Ensured user is on specified team in case of GM/DM, extended test suite

api4/command_test.go

@@ -493,7 +493,7 @@ func TestExecuteCommand(t *testing.T) {
 }
 
 func TestExecuteCommandAgainstChannelOnAnotherTeam(t *testing.T) {
-	th := Setup().InitBasic().InitSystemAdmin()
+	th := Setup().InitBasic()
 	defer th.TearDown()
 	Client := th.Client
 	channel := th.BasicChannel
@@ -516,7 +516,6 @@ func TestExecuteCommandAgainstChannelOnAnotherTeam(t *testing.T) {
 		Method:    model.COMMAND_METHOD_POST,
 		Trigger:   "postcommand",
 	}
-
 	if _, err := th.App.CreateCommand(postCmd); err != nil {
 		t.Fatal("failed to create post command")
 	}
@@ -526,3 +525,131 @@ func TestExecuteCommandAgainstChannelOnAnotherTeam(t *testing.T) {
 	_, resp := Client.ExecuteCommand(channel.Id, "/postcommand")
 	CheckNotFoundStatus(t, resp)
 }
+
+func TestExecuteCommandAgainstChannelUserIsNotIn(t *testing.T) {
+	th := Setup().InitBasic()
+	defer th.TearDown()
+	client := th.Client
+
+	enableCommands := *utils.Cfg.ServiceSettings.EnableCommands
+	allowedInternalConnections := *utils.Cfg.ServiceSettings.AllowedUntrustedInternalConnections
+	defer func() {
+		utils.Cfg.ServiceSettings.EnableCommands = &enableCommands
+		utils.Cfg.ServiceSettings.AllowedUntrustedInternalConnections = &allowedInternalConnections
+	}()
+	*utils.Cfg.ServiceSettings.EnableCommands = true
+	*utils.Cfg.ServiceSettings.AllowedUntrustedInternalConnections = "localhost"
+
+	// create a slash command on some other team where we have permission to do so
+	team2 := th.CreateTeam()
+	postCmd := &model.Command{
+		CreatorId: th.BasicUser.Id,
+		TeamId:    team2.Id,
+		URL:       fmt.Sprintf("http://localhost:%v", th.App.Srv.ListenAddr.Port) + model.API_URL_SUFFIX_V4 + "/teams/command_test",
+		Method:    model.COMMAND_METHOD_POST,
+		Trigger:   "postcommand",
+	}
+	if _, err := th.App.CreateCommand(postCmd); err != nil {
+		t.Fatal("failed to create post command")
+	}
+
+	// make a channel on that team, ensuring that our test user isn't in it
+	channel2 := th.CreateChannelWithClientAndTeam(client, model.CHANNEL_OPEN, team2.Id)
+	if success, _ := client.RemoveUserFromChannel(channel2.Id, th.BasicUser.Id); !success {
+		t.Fatal("Failed to remove user from channel")
+	}
+
+	// we should not be able to run the slash command in channel2, because we aren't in it
+	_, resp := client.ExecuteCommandWithTeam(channel2.Id, team2.Id, "/postcommand")
+	CheckForbiddenStatus(t, resp)
+}
+
+func TestExecuteCommandInDirectMessageChannel(t *testing.T) {
+	th := Setup().InitBasic()
+	defer th.TearDown()
+	client := th.Client
+
+	enableCommands := *utils.Cfg.ServiceSettings.EnableCommands
+	allowedInternalConnections := *utils.Cfg.ServiceSettings.AllowedUntrustedInternalConnections
+	defer func() {
+		utils.Cfg.ServiceSettings.EnableCommands = &enableCommands
+		utils.Cfg.ServiceSettings.AllowedUntrustedInternalConnections = &allowedInternalConnections
+	}()
+	*utils.Cfg.ServiceSettings.EnableCommands = true
+	*utils.Cfg.ServiceSettings.AllowedUntrustedInternalConnections = "localhost"
+
+	// create a slash command on some other team where we have permission to do so
+	team2 := th.CreateTeam()
+	postCmd := &model.Command{
+		CreatorId: th.BasicUser.Id,
+		TeamId:    team2.Id,
+		URL:       fmt.Sprintf("http://localhost:%v", th.App.Srv.ListenAddr.Port) + model.API_URL_SUFFIX_V4 + "/teams/command_test",
+		Method:    model.COMMAND_METHOD_POST,
+		Trigger:   "postcommand",
+	}
+	if _, err := th.App.CreateCommand(postCmd); err != nil {
+		t.Fatal("failed to create post command")
+	}
+
+	// make a direct message channel
+	dmChannel, response := client.CreateDirectChannel(th.BasicUser.Id, th.BasicUser2.Id)
+	CheckCreatedStatus(t, response)
+
+	// we should be able to run the slash command in the DM channel
+	_, resp := client.ExecuteCommandWithTeam(dmChannel.Id, team2.Id, "/postcommand")
+	CheckOKStatus(t, resp)
+
+	// but we can't run the slash command in the DM channel if we sub in some other team's id
+	_, resp = client.ExecuteCommandWithTeam(dmChannel.Id, th.BasicTeam.Id, "/postcommand")
+	CheckNotFoundStatus(t, resp)
+}
+
+func TestExecuteCommandInTeamUserIsNotOn(t *testing.T) {
+	th := Setup().InitBasic()
+	defer th.TearDown()
+	client := th.Client
+
+	enableCommands := *utils.Cfg.ServiceSettings.EnableCommands
+	allowedInternalConnections := *utils.Cfg.ServiceSettings.AllowedUntrustedInternalConnections
+	defer func() {
+		utils.Cfg.ServiceSettings.EnableCommands = &enableCommands
+		utils.Cfg.ServiceSettings.AllowedUntrustedInternalConnections = &allowedInternalConnections
+	}()
+	*utils.Cfg.ServiceSettings.EnableCommands = true
+	*utils.Cfg.ServiceSettings.AllowedUntrustedInternalConnections = "localhost"
+
+	// create a team that the user isn't a part of
+	team2 := th.CreateTeam()
+
+	// create a slash command on that team
+	postCmd := &model.Command{
+		CreatorId: th.BasicUser.Id,
+		TeamId:    team2.Id,
+		URL:       fmt.Sprintf("http://localhost:%v", th.App.Srv.ListenAddr.Port) + model.API_URL_SUFFIX_V4 + "/teams/command_test",
+		Method:    model.COMMAND_METHOD_POST,
+		Trigger:   "postcommand",
+	}
+	if _, err := th.App.CreateCommand(postCmd); err != nil {
+		t.Fatal("failed to create post command")
+	}
+
+	// make a direct message channel
+	dmChannel, response := client.CreateDirectChannel(th.BasicUser.Id, th.BasicUser2.Id)
+	CheckCreatedStatus(t, response)
+
+	// we should be able to run the slash command in the DM channel
+	_, resp := client.ExecuteCommandWithTeam(dmChannel.Id, team2.Id, "/postcommand")
+	CheckOKStatus(t, resp)
+
+	// if the user is removed from the team, they should NOT be able to run the slash command in the DM channel
+	if success, _ := client.RemoveTeamMember(team2.Id, th.BasicUser.Id); !success {
+		t.Fatal("Failed to remove user from team")
+	}
+	_, resp = client.ExecuteCommandWithTeam(dmChannel.Id, team2.Id, "/postcommand")
+	CheckForbiddenStatus(t, resp)
+
+	// if we omit the team id from the request, the slash command will fail because this is a DM channel, and the
+	// team id can't be inherited from the channel
+	_, resp = client.ExecuteCommand(dmChannel.Id, "/postcommand")
+	CheckForbiddenStatus(t, resp)
+}