Fix: Prevent duplicate CLI errors and unescape AI newlines

cmd/matecommit/main.go

@@ -47,8 +47,15 @@ func main() {
 	// through the slog handler at Info level. With the handler's default
 	// Warn threshold, that silently drops every fatal error unless --debug
 	// is passed — and even then it prints mislabeled as "[INFO]".
+	//
+	// Commands are expected to display their own errors via ui.PrintError /
+	// ui.HandleAppError before returning them (wrapped with ui.Shown) — this
+	// is the last-resort net for the few paths that don't, so it only prints
+	// when nothing has shown the error yet.
 	if err := app.Run(context.Background(), os.Args); err != nil {
-		fmt.Fprintln(os.Stderr, err)
+		if !ui.IsShown(err) {
+			fmt.Fprintln(os.Stderr, err)
+		}
 		os.Exit(1)
 	}
 }

internal/ai/gemini/helper.go

@@ -114,6 +114,16 @@ func extractTextFromMap(respMap map[string]interface{}) string {
 	return result.String()
 }
 
+// unescapeLiteralNewlines converts a literal two-character "\n" escape
+// sequence into a real newline character. Despite explicit prompt
+// instructions asking the model not to, it sometimes still emits the
+// escape sequence as text instead of an actual line break inside
+// multi-line Markdown fields (PR bodies, issue descriptions) — this is a
+// deterministic safety net for when that instruction isn't followed.
+func unescapeLiteralNewlines(s string) string {
+	return strings.ReplaceAll(s, `\n`, "\n")
+}
+
 // CleanLabels cleans and validates labels, keeping only the allowed ones.
 // It accepts a list of labels to clean and a list of available labels from the repository.
 // If availableLabels is empty, it falls back to a default list of common labels.

internal/ai/gemini/helper_test.go

@@ -33,6 +33,24 @@ func TestExtractUsage(t *testing.T) {
 	})
 }
 
+func TestUnescapeLiteralNewlines(t *testing.T) {
+	t.Run("replaces literal backslash-n with a real newline", func(t *testing.T) {
+		input := `## Summary\nThis is the body.\n\n## Changes\n- one\n- two`
+		result := unescapeLiteralNewlines(input)
+		assert.Equal(t, "## Summary\nThis is the body.\n\n## Changes\n- one\n- two", result)
+		assert.NotContains(t, result, `\n`)
+	})
+
+	t.Run("leaves real newlines untouched", func(t *testing.T) {
+		input := "## Summary\nAlready a real newline."
+		assert.Equal(t, input, unescapeLiteralNewlines(input))
+	})
+
+	t.Run("empty string stays empty", func(t *testing.T) {
+		assert.Equal(t, "", unescapeLiteralNewlines(""))
+	})
+}
+
 func TestGetGenerateConfig(t *testing.T) {
 	t.Run("default config", func(t *testing.T) {
 		cfg := GetGenerateConfig("gemini-1.5-flash", "", nil)

internal/ai/gemini/issue_content_generator.go

@@ -325,7 +325,7 @@ func (s *GeminiIssueContentGenerator) parseIssueResponse(content string) (*model
 
 	result := &models.IssueGenerationResult{
 		Title:       strings.TrimSpace(jsonResult.Title),
-		Description: strings.TrimSpace(jsonResult.Description),
+		Description: unescapeLiteralNewlines(strings.TrimSpace(jsonResult.Description)),
 		Labels:      jsonResult.Labels,
 	}
 

internal/ai/gemini/pull_requests_summarizer_service.go

@@ -225,7 +225,7 @@ func (gps *GeminiPRSummarizer) GeneratePRSummary(ctx context.Context, prContent
 
 	return models.PRSummary{
 		Title:  jsonSummary.Title,
-		Body:   jsonSummary.Body,
+		Body:   unescapeLiteralNewlines(jsonSummary.Body),
 		Labels: CleanLabels(jsonSummary.Labels, availableLabels),
 		Usage:  usage,
 	}, nil

internal/commands/config/doctor.go

@@ -99,7 +99,7 @@ func (d *DoctorCommand) runHealthCheck(ctx context.Context, t *i18n.Translations
 	} else if len(errors) == 0 {
 		ui.PrintWarning(t.GetMessage("doctor.has_warnings", 0, nil))
 	} else {
-		ui.PrintError(os.Stdout, t.GetMessage("doctor.has_errors", 0, nil))
+		_ = ui.PrintError(os.Stdout, t.GetMessage("doctor.has_errors", 0, nil))
 	}
 
 	fmt.Println()

internal/commands/config/init.go

@@ -55,8 +55,7 @@ func initConfigAction(cfg *config.Config, t *i18n.Translations) cli.ActionFunc {
 	return func(ctx context.Context, command *cli.Command) error {
 		localCfg, useLocal, err := resolveTargetConfig(command, cfg, t)
 		if err != nil {
-			ui.PrintError(os.Stdout, err.Error())
-			return err
+			return ui.PrintError(os.Stdout, err.Error())
 		}
 
 		if useLocal {
@@ -454,7 +453,7 @@ func validateGeminiAPIKey(ctx context.Context, apiKey string, t *i18n.Translatio
 	summarizer, err := gemini.NewGeminiCommitSummarizer(testCtx, testCfg, nil)
 	if err != nil {
 		spinner.Error(t.GetMessage("config.api_key_invalid", 0, nil))
-		ui.PrintError(os.Stdout, t.GetMessage("config.check_api_key_error", 0, struct{ Error string }{err.Error()}))
+		_ = ui.PrintError(os.Stdout, t.GetMessage("config.check_api_key_error", 0, struct{ Error string }{err.Error()}))
 		return false
 	}
 
@@ -463,7 +462,7 @@ func validateGeminiAPIKey(ctx context.Context, apiKey string, t *i18n.Translatio
 	// is authorized — CountTokens is the cheapest real call available.
 	if _, err := summarizer.CountTokens(testCtx, "ping"); err != nil {
 		spinner.Error(t.GetMessage("config.api_key_invalid", 0, nil))
-		ui.PrintError(os.Stdout, t.GetMessage("config.check_api_key_error", 0, struct{ Error string }{err.Error()}))
+		_ = ui.PrintError(os.Stdout, t.GetMessage("config.check_api_key_error", 0, struct{ Error string }{err.Error()}))
 		return false
 	}
 
@@ -488,7 +487,7 @@ func validateGitHubToken(ctx context.Context, token string, t *i18n.Translations
 	user, resp, err := client.Users.Get(testCtx, "")
 	if err != nil {
 		spinner.Error(t.GetMessage("config.github_token_invalid", 0, nil))
-		ui.PrintError(os.Stdout, t.GetMessage("config.check_token_error", 0, struct{ Error string }{err.Error()}))
+		_ = ui.PrintError(os.Stdout, t.GetMessage("config.check_token_error", 0, struct{ Error string }{err.Error()}))
 		return false
 	}
 
@@ -573,7 +572,7 @@ func validateJiraConnection(ctx context.Context, baseURL, email, token string, t
 	req, err := http.NewRequestWithContext(testCtx, "GET", testURL, nil)
 	if err != nil {
 		spinner.Error(t.GetMessage("config.jira_connection_failed", 0, nil))
-		ui.PrintError(os.Stdout, t.GetMessage("config.jira_error_creating_request", 0, struct{ Error error }{err}))
+		_ = ui.PrintError(os.Stdout, t.GetMessage("config.jira_error_creating_request", 0, struct{ Error error }{err}))
 		return false
 	}
 
@@ -583,7 +582,7 @@ func validateJiraConnection(ctx context.Context, baseURL, email, token string, t
 	resp, err := client.Do(req)
 	if err != nil {
 		spinner.Error(t.GetMessage("config.jira_connection_failed", 0, nil))
-		ui.PrintError(os.Stdout, t.GetMessage("config.check_jira_error", 0, struct{ Error string }{err.Error()}))
+		_ = ui.PrintError(os.Stdout, t.GetMessage("config.check_jira_error", 0, struct{ Error string }{err.Error()}))
 		return false
 	}
 	defer func() {
@@ -603,7 +602,7 @@ func validateJiraConnection(ctx context.Context, baseURL, email, token string, t
 		default:
 			errorMsg = t.GetMessage("config.jira_http_error", 0, struct{ Code int }{resp.StatusCode})
 		}
-		ui.PrintError(os.Stdout, errorMsg)
+		_ = ui.PrintError(os.Stdout, errorMsg)
 		return false
 	}
 

internal/commands/config/set.go

@@ -32,42 +32,34 @@ func (c *ConfigCommandFactory) newSetCommand(t *i18n.Translations, cfg *config.C
 		},
 		Action: func(ctx context.Context, command *cli.Command) error {
 			if command.Args().Len() < 2 {
-				ui.PrintError(os.Stdout, t.GetMessage("config_set_error_args", 0, nil))
-				return fmt.Errorf("missing arguments")
+				return ui.PrintError(os.Stdout, t.GetMessage("config_set_error_args", 0, nil))
 			}
 
 			key := strings.ToLower(command.Args().Get(0))
 			value := command.Args().Get(1)
 
 			targetCfg, useLocal, err := resolveTargetConfig(command, cfg, t)
 			if err != nil {
-				ui.PrintError(os.Stdout, err.Error())
-				return err
+				return ui.PrintError(os.Stdout, err.Error())
 			}
 
 			switch key {
 			case "lang", "language":
 				if isValidLanguage(value) {
 					targetCfg.Language = value
 				} else {
-					err := fmt.Errorf("invalid language: %s", value)
-					ui.PrintError(os.Stdout, err.Error())
-					return err
+					return ui.PrintError(os.Stdout, fmt.Sprintf("invalid language: %s", value))
 				}
 			case "emoji", "use_emoji":
 				boolVal, parseErr := strconv.ParseBool(value)
 				if parseErr != nil {
-					err := fmt.Errorf("invalid boolean value: %s", value)
-					ui.PrintError(os.Stdout, err.Error())
-					return err
+					return ui.PrintError(os.Stdout, fmt.Sprintf("invalid boolean value: %s", value))
 				}
 				targetCfg.UseEmoji = boolVal
 			case "count", "suggestions_count":
 				intVal, parseErr := strconv.Atoi(value)
 				if parseErr != nil || intVal < 1 || intVal > 10 {
-					err := fmt.Errorf("invalid count (must be 1-10): %s", value)
-					ui.PrintError(os.Stdout, err.Error())
-					return err
+					return ui.PrintError(os.Stdout, fmt.Sprintf("invalid count (must be 1-10): %s", value))
 				}
 				targetCfg.SuggestionsCount = intVal
 			case "active-ai", "active_ai":
@@ -79,9 +71,7 @@ func (c *ConfigCommandFactory) newSetCommand(t *i18n.Translations, cfg *config.C
 					}
 					targetCfg.AIConfig.Models[targetCfg.AIConfig.ActiveAI] = config.Model(value)
 				} else {
-					err := fmt.Errorf("no active AI provider configured")
-					ui.PrintError(os.Stdout, err.Error())
-					return err
+					return ui.PrintError(os.Stdout, "no active AI provider configured")
 				}
 			case "active-vcs", "active_vcs":
 				targetCfg.ActiveVCSProvider = value
@@ -90,9 +80,7 @@ func (c *ConfigCommandFactory) newSetCommand(t *i18n.Translations, cfg *config.C
 			case "git.email", "git-email":
 				targetCfg.GitFallback.UserEmail = value
 			default:
-				err := fmt.Errorf("unknown configuration key: %s", key)
-				ui.PrintError(os.Stdout, err.Error())
-				return err
+				return ui.PrintError(os.Stdout, fmt.Sprintf("unknown configuration key: %s", key))
 			}
 
 			if useLocal {
@@ -102,8 +90,7 @@ func (c *ConfigCommandFactory) newSetCommand(t *i18n.Translations, cfg *config.C
 			}
 
 			if err != nil {
-				ui.PrintError(os.Stdout, t.GetMessage("ui_error.error_saving_config", 0, nil))
-				return err
+				return ui.PrintError(os.Stdout, t.GetMessage("ui_error.error_saving_config", 0, nil))
 			}
 
 			scope := "global"

internal/commands/handler/suggestions.go

@@ -209,8 +209,7 @@ func (h *SuggestionHandler) handleCommitSelection(ctx context.Context, suggestio
 	if _, err := fmt.Scan(&input); err != nil {
 		logger.Error(ctx, "failed to read user selection", err)
 		msg := h.t.GetMessage("commit.error_reading_selection", 0, struct{ Error error }{err})
-		ui.PrintError(os.Stdout, msg)
-		return fmt.Errorf("%s", msg)
+		return ui.PrintError(os.Stdout, msg)
 	}
 
 	input = strings.TrimSpace(strings.ToLower(input))
@@ -234,8 +233,7 @@ func (h *SuggestionHandler) handleCommitSelection(ctx context.Context, suggestio
 	if _, err := fmt.Sscanf(input, "%d", &selection); err != nil || selection < 1 || selection > len(suggestions) {
 		log.Warn("invalid selection", "input", input, "max", len(suggestions))
 		msg := h.t.GetMessage("commit.invalid_selection", 0, struct{ Number int }{len(suggestions)})
-		ui.PrintError(os.Stdout, msg)
-		return fmt.Errorf("%s", msg)
+		return ui.PrintError(os.Stdout, msg)
 	}
 
 	log.Info("processing selected commit", "selection", selection)
@@ -279,8 +277,7 @@ func (h *SuggestionHandler) processCommit(ctx context.Context, suggestion models
 		editedMessage, err := ui.EditCommitMessage(commitTitle, editorError)
 		if err != nil {
 			logger.Error(ctx, "failed to edit commit message", err)
-			ui.PrintError(os.Stdout, h.t.GetMessage("ui_preview.error_editing_message", 0, struct{ Error error }{err}))
-			return err
+			return ui.PrintError(os.Stdout, h.t.GetMessage("ui_preview.error_editing_message", 0, struct{ Error error }{err}))
 		}
 		if editedMessage == "" {
 			ui.PrintWarning(h.t.GetMessage("ui_preview.commit_cancelled", 0, nil))

internal/commands/issues/from_plan.go

@@ -114,8 +114,7 @@ func (f *IssuesCommandFactory) createFromPlanAction(t *i18n.Translations, cfg *c
 					Number int
 					Error  string
 				}{1, err.Error()})
-			ui.PrintError(os.Stdout, errMsg)
-			return err
+			return ui.PrintError(os.Stdout, errMsg)
 		}
 
 		emoji := ""

internal/commands/issues/issues.go

@@ -177,15 +177,13 @@ func (f *IssuesCommandFactory) createGenerateAction(t *i18n.Translations, cfg *c
 		if sourcesCount == 0 {
 			log.Error("no input source provided",
 				"duration_ms", time.Since(start).Milliseconds())
-			ui.PrintError(os.Stdout, t.GetMessage("issue.error_no_input", 0, nil))
-			return fmt.Errorf("%s", t.GetMessage("issue.error_no_input", 0, nil))
+			return ui.PrintError(os.Stdout, t.GetMessage("issue.error_no_input", 0, nil))
 		}
 
 		if sourcesCount > 1 {
 			log.Error("multiple input sources provided",
 				"duration_ms", time.Since(start).Milliseconds())
-			ui.PrintError(os.Stdout, t.GetMessage("issue.error_multiple_sources", 0, nil))
-			return fmt.Errorf("%s", t.GetMessage("issue.error_multiple_sources", 0, nil))
+			return ui.PrintError(os.Stdout, t.GetMessage("issue.error_multiple_sources", 0, nil))
 		}
 
 		ui.PrintSectionBanner(t.GetMessage("issue.banner", 0, nil))
@@ -195,8 +193,7 @@ func (f *IssuesCommandFactory) createGenerateAction(t *i18n.Translations, cfg *c
 			log.Error("failed to create issue service",
 				"error", err,
 				"duration_ms", time.Since(start).Milliseconds())
-			ui.PrintError(os.Stdout, fmt.Sprintf("%s: %v", t.GetMessage("issue.error_generating", 0, nil), err))
-			return err
+			return ui.PrintError(os.Stdout, fmt.Sprintf("%s: %v", t.GetMessage("issue.error_generating", 0, nil), err))
 		}
 
 		var spinnerMsg string
@@ -229,8 +226,7 @@ func (f *IssuesCommandFactory) createGenerateAction(t *i18n.Translations, cfg *c
 				"from_diff", fromDiff,
 				"from_pr", fromPR,
 				"duration_ms", time.Since(start).Milliseconds())
-			ui.HandleAppError(err)
-			return err
+			return ui.HandleAppError(err)
 		}
 
 		log.Debug("issue generated",
@@ -283,8 +279,7 @@ func (f *IssuesCommandFactory) createGenerateAction(t *i18n.Translations, cfg *c
 			log.Error("failed to create issue",
 				"error", err,
 				"duration_ms", time.Since(start).Milliseconds())
-			ui.HandleAppError(err)
-			return err
+			return ui.HandleAppError(err)
 		}
 
 		log.Info("issue created successfully",
@@ -394,16 +389,14 @@ func (f *IssuesCommandFactory) createLinkAction(t *i18n.Translations, _ *config.
 			log.Error("invalid PR number",
 				"pr_number", prNumber,
 				"duration_ms", time.Since(start).Milliseconds())
-			ui.PrintError(os.Stdout, t.GetMessage("issue.error_invalid_pr", 0, nil))
-			return fmt.Errorf("invalid PR number")
+			return ui.PrintError(os.Stdout, t.GetMessage("issue.error_invalid_pr", 0, nil))
 		}
 
 		if issueNumber <= 0 {
 			log.Error("invalid issue number",
 				"issue_number", issueNumber,
 				"duration_ms", time.Since(start).Milliseconds())
-			ui.PrintError(os.Stdout, t.GetMessage("issue.error_invalid_issue", 0, nil))
-			return fmt.Errorf("invalid issue number")
+			return ui.PrintError(os.Stdout, t.GetMessage("issue.error_invalid_issue", 0, nil))
 		}
 
 		ui.PrintSectionBanner(t.GetMessage("issue.link_banner", 0, nil))
@@ -413,8 +406,7 @@ func (f *IssuesCommandFactory) createLinkAction(t *i18n.Translations, _ *config.
 			log.Error("failed to create issue service",
 				"error", err,
 				"duration_ms", time.Since(start).Milliseconds())
-			ui.HandleAppError(err)
-			return err
+			return ui.HandleAppError(err)
 		}
 
 		spinner := ui.NewSmartSpinner(t.GetMessage("issue.linking", 0, struct {
@@ -432,8 +424,7 @@ func (f *IssuesCommandFactory) createLinkAction(t *i18n.Translations, _ *config.
 				"pr_number", prNumber,
 				"issue_number", issueNumber,
 				"duration_ms", time.Since(start).Milliseconds())
-			ui.PrintError(os.Stdout, fmt.Sprintf("%s: %v", t.GetMessage("issue.error_linking", 0, nil), err))
-			return err
+			return ui.PrintError(os.Stdout, fmt.Sprintf("%s: %v", t.GetMessage("issue.error_linking", 0, nil), err))
 		}
 
 		log.Info("issue linked to PR successfully",

internal/commands/issues/templates.go

@@ -37,8 +37,7 @@ func (f *IssuesCommandFactory) newTemplateCommand(t *i18n.Translations, _ *confi
 					ui.PrintInfo(t.GetMessage("issue.template_init_info", 0, nil))
 
 					if err := templateService.InitializeTemplates(ctx, force); err != nil {
-						ui.HandleAppError(err, t)
-						return err
+						return ui.HandleAppError(err, t)
 					}
 
 					templatesDir, _ := templateService.GetTemplatesDir(ctx)
@@ -54,8 +53,7 @@ func (f *IssuesCommandFactory) newTemplateCommand(t *i18n.Translations, _ *confi
 				Action: func(ctx context.Context, cmd *cli.Command) error {
 					templates, err := templateService.ListTemplates(ctx)
 					if err != nil {
-						ui.HandleAppError(err, t)
-						return err
+						return ui.HandleAppError(err, t)
 					}
 
 					if len(templates) == 0 {

internal/commands/pull_requests/summarize.go

@@ -103,8 +103,8 @@ func (c *SummarizeCommand) CreateCommand(t *i18n.Translations, _ *cfg.Config) *c
 					"pr_number", prNumber,
 					"duration_ms", time.Since(start).Milliseconds())
 				spinner.Error(t.GetMessage("ui.error_generating_pr_summary", 0, nil))
-				ui.HandleAppError(err)
-				return fmt.Errorf(t.GetMessage("error.pr_summary_error", 0, nil)+": %w", err)
+				_ = ui.HandleAppError(err)
+				return ui.Shown(fmt.Errorf(t.GetMessage("error.pr_summary_error", 0, nil)+": %w", err))
 			}
 
 			log.Info("PR summarized successfully",

internal/commands/release/edit.go

@@ -60,8 +60,7 @@ func editReleaseAction(releaseSvc releaseService, gitSvc gitService, trans *i18n
 
 		existingRelease, err := releaseSvc.GetRelease(ctx, version)
 		if err != nil {
-			ui.HandleAppError(err)
-			return fmt.Errorf("%s", trans.GetMessage("release.error_fetching_release", 0, struct{ Error string }{err.Error()}))
+			return ui.HandleAppError(err)
 		}
 
 		content := existingRelease.Body