Migrate to idiomatic error handling in app/command.go (#9675)

app/command.go

@@ -52,7 +52,9 @@ func (a *App) CreateCommandPost(post *model.Post, teamId string, response *model
 
 	if response.ResponseType == model.COMMAND_RESPONSE_TYPE_IN_CHANNEL {
 		return a.CreatePostMissingChannel(post, true)
-	} else if (response.ResponseType == "" || response.ResponseType == model.COMMAND_RESPONSE_TYPE_EPHEMERAL) && (response.Text != "" || response.Attachments != nil) {
+	}
+
+	if (response.ResponseType == "" || response.ResponseType == model.COMMAND_RESPONSE_TYPE_EPHEMERAL) && (response.Text != "" || response.Attachments != nil) {
 		post.ParentId = ""
 		a.SendEphemeralPost(post.UserId, post)
 	}
@@ -83,16 +85,17 @@ func (a *App) ListAutocompleteCommands(teamId string, T goi18n.TranslateFunc) ([
 	}
 
 	if *a.Config().ServiceSettings.EnableCommands {
-		if result := <-a.Srv.Store.Command().GetByTeam(teamId); result.Err != nil {
+		result := <-a.Srv.Store.Command().GetByTeam(teamId)
+		if result.Err != nil {
 			return nil, result.Err
-		} else {
-			teamCmds := result.Data.([]*model.Command)
-			for _, cmd := range teamCmds {
-				if cmd.AutoComplete && !seen[cmd.Id] {
-					cmd.Sanitize()
-					seen[cmd.Trigger] = true
-					commands = append(commands, cmd)
-				}
+		}
+
+		teamCmds := result.Data.([]*model.Command)
+		for _, cmd := range teamCmds {
+			if cmd.AutoComplete && !seen[cmd.Id] {
+				cmd.Sanitize()
+				seen[cmd.Trigger] = true
+				commands = append(commands, cmd)
 			}
 		}
 	}
@@ -105,11 +108,12 @@ func (a *App) ListTeamCommands(teamId string) ([]*model.Command, *model.AppError
 		return nil, model.NewAppError("ListTeamCommands", "api.command.disabled.app_error", nil, "", http.StatusNotImplemented)
 	}
 
-	if result := <-a.Srv.Store.Command().GetByTeam(teamId); result.Err != nil {
+	result := <-a.Srv.Store.Command().GetByTeam(teamId)
+	if result.Err != nil {
 		return nil, result.Err
-	} else {
-		return result.Data.([]*model.Command), nil
 	}
+
+	return result.Data.([]*model.Command), nil
 }
 
 func (a *App) ListAllCommands(teamId string, T goi18n.TranslateFunc) ([]*model.Command, *model.AppError) {
@@ -134,16 +138,16 @@ func (a *App) ListAllCommands(teamId string, T goi18n.TranslateFunc) ([]*model.C
 	}
 
 	if *a.Config().ServiceSettings.EnableCommands {
-		if result := <-a.Srv.Store.Command().GetByTeam(teamId); result.Err != nil {
+		result := <-a.Srv.Store.Command().GetByTeam(teamId)
+		if result.Err != nil {
 			return nil, result.Err
-		} else {
-			teamCmds := result.Data.([]*model.Command)
-			for _, cmd := range teamCmds {
-				if !seen[cmd.Trigger] {
-					cmd.Sanitize()
-					seen[cmd.Trigger] = true
-					commands = append(commands, cmd)
-				}
+		}
+		teamCmds := result.Data.([]*model.Command)
+		for _, cmd := range teamCmds {
+			if !seen[cmd.Trigger] {
+				cmd.Sanitize()
+				seen[cmd.Trigger] = true
+				commands = append(commands, cmd)
 			}
 		}
 	}
@@ -165,9 +169,11 @@ func (a *App) ExecuteCommand(args *model.CommandArgs) (*model.CommandResponse, *
 		}
 	}
 
-	if cmd, response, err := a.ExecutePluginCommand(args); err != nil {
-		return nil, err
-	} else if cmd != nil {
+	cmd, response, appErr := a.ExecutePluginCommand(args)
+	if appErr != nil {
+		return nil, appErr
+	}
+	if cmd != nil {
 		return a.HandleCommandResponse(cmd, args, response, true)
 	}
 
@@ -179,93 +185,91 @@ func (a *App) ExecuteCommand(args *model.CommandArgs) (*model.CommandResponse, *
 	teamChan := a.Srv.Store.Team().Get(args.TeamId)
 	userChan := a.Srv.Store.User().Get(args.UserId)
 
-	if result := <-a.Srv.Store.Command().GetByTeam(args.TeamId); result.Err != nil {
+	result := <-a.Srv.Store.Command().GetByTeam(args.TeamId)
+	if result.Err != nil {
 		return nil, result.Err
-	} else {
+	}
 
-		var team *model.Team
-		if tr := <-teamChan; tr.Err != nil {
-			return nil, tr.Err
-		} else {
-			team = tr.Data.(*model.Team)
-		}
+	tr := <-teamChan
+	if tr.Err != nil {
+		return nil, tr.Err
+	}
+	team := tr.Data.(*model.Team)
 
-		var user *model.User
-		if ur := <-userChan; ur.Err != nil {
-			return nil, ur.Err
-		} else {
-			user = ur.Data.(*model.User)
-		}
+	ur := <-userChan
+	if ur.Err != nil {
+		return nil, ur.Err
+	}
+	user := ur.Data.(*model.User)
 
-		var channel *model.Channel
-		if cr := <-chanChan; cr.Err != nil {
-			return nil, cr.Err
-		} else {
-			channel = cr.Data.(*model.Channel)
-		}
+	cr := <-chanChan
+	if cr.Err != nil {
+		return nil, cr.Err
+	}
+	channel := cr.Data.(*model.Channel)
 
-		teamCmds := result.Data.([]*model.Command)
-		for _, cmd := range teamCmds {
-			if trigger == cmd.Trigger {
-				mlog.Debug(fmt.Sprintf(utils.T("api.command.execute_command.debug"), trigger, args.UserId))
+	teamCmds := result.Data.([]*model.Command)
+	for _, cmd := range teamCmds {
+		if trigger == cmd.Trigger {
+			mlog.Debug(fmt.Sprintf(utils.T("api.command.execute_command.debug"), trigger, args.UserId))
 
-				p := url.Values{}
-				p.Set("token", cmd.Token)
+			p := url.Values{}
+			p.Set("token", cmd.Token)
 
-				p.Set("team_id", cmd.TeamId)
-				p.Set("team_domain", team.Name)
+			p.Set("team_id", cmd.TeamId)
+			p.Set("team_domain", team.Name)
 
-				p.Set("channel_id", args.ChannelId)
-				p.Set("channel_name", channel.Name)
+			p.Set("channel_id", args.ChannelId)
+			p.Set("channel_name", channel.Name)
 
-				p.Set("user_id", args.UserId)
-				p.Set("user_name", user.Username)
+			p.Set("user_id", args.UserId)
+			p.Set("user_name", user.Username)
 
-				p.Set("command", "/"+trigger)
-				p.Set("text", message)
+			p.Set("command", "/"+trigger)
+			p.Set("text", message)
 
-				if hook, err := a.CreateCommandWebhook(cmd.Id, args); err != nil {
-					return nil, model.NewAppError("command", "api.command.execute_command.failed.app_error", map[string]interface{}{"Trigger": trigger}, err.Error(), http.StatusInternalServerError)
-				} else {
-					p.Set("response_url", args.SiteURL+"/hooks/commands/"+hook.Id)
-				}
-
-				var req *http.Request
-				if cmd.Method == model.COMMAND_METHOD_GET {
-					req, _ = http.NewRequest(http.MethodGet, cmd.URL, nil)
-
-					if req.URL.RawQuery != "" {
-						req.URL.RawQuery += "&"
-					}
-					req.URL.RawQuery += p.Encode()
-				} else {
-					req, _ = http.NewRequest(http.MethodPost, cmd.URL, strings.NewReader(p.Encode()))
-				}
-
-				req.Header.Set("Accept", "application/json")
-				req.Header.Set("Authorization", "Token "+cmd.Token)
-				if cmd.Method == model.COMMAND_METHOD_POST {
-					req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
-				}
-
-				if resp, err := a.HTTPService.MakeClient(false).Do(req); err != nil {
-					return nil, model.NewAppError("command", "api.command.execute_command.failed.app_error", map[string]interface{}{"Trigger": trigger}, err.Error(), http.StatusInternalServerError)
-				} else {
-					if resp.StatusCode == http.StatusOK {
-						if response, err := model.CommandResponseFromHTTPBody(resp.Header.Get("Content-Type"), resp.Body); err != nil {
-							return nil, model.NewAppError("command", "api.command.execute_command.failed.app_error", map[string]interface{}{"Trigger": trigger}, err.Error(), http.StatusInternalServerError)
-						} else if response == nil {
-							return nil, model.NewAppError("command", "api.command.execute_command.failed_empty.app_error", map[string]interface{}{"Trigger": trigger}, "", http.StatusInternalServerError)
-						} else {
-							return a.HandleCommandResponse(cmd, args, response, false)
-						}
-					} else {
-						defer resp.Body.Close()
-						body, _ := ioutil.ReadAll(resp.Body)
-						return nil, model.NewAppError("command", "api.command.execute_command.failed_resp.app_error", map[string]interface{}{"Trigger": trigger, "Status": resp.Status}, string(body), http.StatusInternalServerError)
-					}
-				}
+			hook, appErr := a.CreateCommandWebhook(cmd.Id, args)
+			if appErr != nil {
+				return nil, model.NewAppError("command", "api.command.execute_command.failed.app_error", map[string]interface{}{"Trigger": trigger}, appErr.Error(), http.StatusInternalServerError)
 			}
+			p.Set("response_url", args.SiteURL+"/hooks/commands/"+hook.Id)
+
+			var req *http.Request
+			if cmd.Method == model.COMMAND_METHOD_GET {
+				req, _ = http.NewRequest(http.MethodGet, cmd.URL, nil)
+
+				if req.URL.RawQuery != "" {
+					req.URL.RawQuery += "&"
+				}
+				req.URL.RawQuery += p.Encode()
+			} else {
+				req, _ = http.NewRequest(http.MethodPost, cmd.URL, strings.NewReader(p.Encode()))
+			}
+
+			req.Header.Set("Accept", "application/json")
+			req.Header.Set("Authorization", "Token "+cmd.Token)
+			if cmd.Method == model.COMMAND_METHOD_POST {
+				req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+			}
+
+			resp, err := a.HTTPService.MakeClient(false).Do(req)
+			if err != nil {
+				return nil, model.NewAppError("command", "api.command.execute_command.failed.app_error", map[string]interface{}{"Trigger": trigger}, err.Error(), http.StatusInternalServerError)
+			}
+			if resp.StatusCode != http.StatusOK {
+				defer resp.Body.Close()
+				body, _ := ioutil.ReadAll(resp.Body)
+				return nil, model.NewAppError("command", "api.command.execute_command.failed_resp.app_error", map[string]interface{}{"Trigger": trigger, "Status": resp.Status}, string(body), http.StatusInternalServerError)
+			}
+
+			response, err := model.CommandResponseFromHTTPBody(resp.Header.Get("Content-Type"), resp.Body)
+			if err != nil {
+				return nil, model.NewAppError("command", "api.command.execute_command.failed.app_error", map[string]interface{}{"Trigger": trigger}, err.Error(), http.StatusInternalServerError)
+			}
+			if response == nil {
+				return nil, model.NewAppError("command", "api.command.execute_command.failed_empty.app_error", map[string]interface{}{"Trigger": trigger}, "", http.StatusInternalServerError)
+			}
+			return a.HandleCommandResponse(cmd, args, response, false)
 		}
 	}
 
@@ -327,28 +331,31 @@ func (a *App) CreateCommand(cmd *model.Command) (*model.Command, *model.AppError
 
 	cmd.Trigger = strings.ToLower(cmd.Trigger)
 
-	if result := <-a.Srv.Store.Command().GetByTeam(cmd.TeamId); result.Err != nil {
+	result := <-a.Srv.Store.Command().GetByTeam(cmd.TeamId)
+	if result.Err != nil {
 		return nil, result.Err
-	} else {
-		teamCmds := result.Data.([]*model.Command)
-		for _, existingCommand := range teamCmds {
-			if cmd.Trigger == existingCommand.Trigger {
-				return nil, model.NewAppError("CreateCommand", "api.command.duplicate_trigger.app_error", nil, "", http.StatusBadRequest)
-			}
-		}
-		for _, builtInProvider := range commandProviders {
-			builtInCommand := builtInProvider.GetCommand(a, utils.T)
-			if builtInCommand != nil && cmd.Trigger == builtInCommand.Trigger {
-				return nil, model.NewAppError("CreateCommand", "api.command.duplicate_trigger.app_error", nil, "", http.StatusBadRequest)
-			}
+	}
+
+	teamCmds := result.Data.([]*model.Command)
+	for _, existingCommand := range teamCmds {
+		if cmd.Trigger == existingCommand.Trigger {
+			return nil, model.NewAppError("CreateCommand", "api.command.duplicate_trigger.app_error", nil, "", http.StatusBadRequest)
 		}
 	}
 
-	if result := <-a.Srv.Store.Command().Save(cmd); result.Err != nil {
-		return nil, result.Err
-	} else {
-		return result.Data.(*model.Command), nil
+	for _, builtInProvider := range commandProviders {
+		builtInCommand := builtInProvider.GetCommand(a, utils.T)
+		if builtInCommand != nil && cmd.Trigger == builtInCommand.Trigger {
+			return nil, model.NewAppError("CreateCommand", "api.command.duplicate_trigger.app_error", nil, "", http.StatusBadRequest)
+		}
 	}
+
+	result = <-a.Srv.Store.Command().Save(cmd)
+	if result.Err != nil {
+		return nil, result.Err
+	}
+
+	return result.Data.(*model.Command), nil
 }
 
 func (a *App) GetCommand(commandId string) (*model.Command, *model.AppError) {
@@ -356,12 +363,13 @@ func (a *App) GetCommand(commandId string) (*model.Command, *model.AppError) {
 		return nil, model.NewAppError("GetCommand", "api.command.disabled.app_error", nil, "", http.StatusNotImplemented)
 	}
 
-	if result := <-a.Srv.Store.Command().Get(commandId); result.Err != nil {
+	result := <-a.Srv.Store.Command().Get(commandId)
+	if result.Err != nil {
 		result.Err.StatusCode = http.StatusNotFound
 		return nil, result.Err
-	} else {
-		return result.Data.(*model.Command), nil
 	}
+
+	return result.Data.(*model.Command), nil
 }
 
 func (a *App) UpdateCommand(oldCmd, updatedCmd *model.Command) (*model.Command, *model.AppError) {
@@ -378,17 +386,18 @@ func (a *App) UpdateCommand(oldCmd, updatedCmd *model.Command) (*model.Command,
 	updatedCmd.CreatorId = oldCmd.CreatorId
 	updatedCmd.TeamId = oldCmd.TeamId
 
-	if result := <-a.Srv.Store.Command().Update(updatedCmd); result.Err != nil {
+	result := <-a.Srv.Store.Command().Update(updatedCmd)
+	if result.Err != nil {
 		return nil, result.Err
-	} else {
-		return result.Data.(*model.Command), nil
 	}
+	return result.Data.(*model.Command), nil
 }
 
 func (a *App) MoveCommand(team *model.Team, command *model.Command) *model.AppError {
 	command.TeamId = team.Id
 
-	if result := <-a.Srv.Store.Command().Update(command); result.Err != nil {
+	result := <-a.Srv.Store.Command().Update(command)
+	if result.Err != nil {
 		return result.Err
 	}
 
@@ -402,11 +411,12 @@ func (a *App) RegenCommandToken(cmd *model.Command) (*model.Command, *model.AppE
 
 	cmd.Token = model.NewId()
 
-	if result := <-a.Srv.Store.Command().Update(cmd); result.Err != nil {
+	result := <-a.Srv.Store.Command().Update(cmd)
+	if result.Err != nil {
 		return nil, result.Err
-	} else {
-		return result.Data.(*model.Command), nil
 	}
+
+	return result.Data.(*model.Command), nil
 }
 
 func (a *App) DeleteCommand(commandId string) *model.AppError {