add human friendly error messages

pkg/bot/discord.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"net/http"
 	"regexp"
 	"strings"
 	"sync"
@@ -269,7 +270,7 @@ func (b *Discord) send(channelID string, resp interactive.CoreMessage) error {
 		return fmt.Errorf("while formatting message: %w", err)
 	}
 	if _, err := b.api.ChannelMessageSendComplex(channelID, discordMsg); err != nil {
-		return fmt.Errorf("while sending message: %w", err)
+		return fmt.Errorf("while sending message: %w", discordError(err, channelID))
 	}
 
 	b.log.Debugf("Message successfully sent to channel %q", channelID)
@@ -355,7 +356,7 @@ func discordChannelsConfigFrom(log logrus.FieldLogger, api *discordgo.Session, c
 
 		channelData, err := api.Channel(channCfg.Identifier())
 		if err != nil {
-			return nil, fmt.Errorf("while getting channel name for ID %q: %w", channCfg.Identifier(), err)
+			return nil, fmt.Errorf("while getting channel name for ID %q: %w", channCfg.Identifier(), discordError(err, channCfg.Identifier()))
 		}
 
 		res[channCfg.Identifier()] = channelConfigByID{
@@ -377,3 +378,16 @@ func discordBotMentionRegex(botID string) (*regexp.Regexp, error) {
 
 	return botMentionRegex, nil
 }
+
+func discordError(err error, channel string) error {
+	switch err := err.(type) {
+	case *discordgo.RESTError:
+		switch err.Response.StatusCode {
+		case http.StatusUnauthorized:
+			return errors.New("invalid discord credentials")
+		case http.StatusNotFound:
+			return fmt.Errorf("channel %q not found", channel)
+		}
+	}
+	return err
+}

pkg/bot/slack_shared.go

@@ -42,6 +42,18 @@ func slackBotMentionRegex(botID string) (*regexp.Regexp, error) {
 	return botMentionRegex, nil
 }
 
+func slackError(err error, channel string) error {
+	switch err.Error() {
+	case "channel_not_found":
+		err = fmt.Errorf("channel %q not found", channel)
+	case "not_in_channel":
+		err = fmt.Errorf("botkube is not in channel %q", channel)
+	case "invalid_auth":
+		err = fmt.Errorf("invalid slack credentials")
+	}
+	return err
+}
+
 // slackMessage contains message details to execute command and send back the result
 type slackMessage struct {
 	Text            string

pkg/bot/slack_socket.go

@@ -60,7 +60,7 @@ func NewSocketSlack(log logrus.FieldLogger, commGroupName string, cfg config.Soc
 
 	authResp, err := client.AuthTest()
 	if err != nil {
-		return nil, fmt.Errorf("while testing the ability to do auth Slack request: %w", err)
+		return nil, fmt.Errorf("while testing the ability to do auth Slack request: %w", slackError(err, ""))
 	}
 	botID := authResp.UserID
 
@@ -422,7 +422,7 @@ func (b *SocketSlack) send(ctx context.Context, event slackMessage, resp interac
 		}
 	} else {
 		if _, _, err := b.client.PostMessageContext(ctx, event.Channel, options...); err != nil {
-			return fmt.Errorf("while posting Slack message: %w", err)
+			return fmt.Errorf("while posting Slack message: %w", slackError(err, event.Channel))
 		}
 	}