test(cmd): add CLI workflow coverage and harden GitHub null handling

AGENT.md

@@ -35,7 +35,10 @@ go build -o github2jira .
 go install .
 ```
 
-There is no Makefile, goreleaser, or CI pipeline. Standard Go tooling only.
+The repository uses standard Go tooling. There is no Makefile.
+
+Release builds are configured through `.goreleaser.yaml`, and GitHub Actions
+workflows under `.github/workflows/` run CI and tagged releases.
 
 ## Testing
 
@@ -56,7 +59,8 @@ go vet ./...
 golangci-lint run ./...
 ```
 
-No `.golangci.yml` config file; default rules apply.
+Use `golangci-lint` for local linting alongside `go vet`. CI currently enforces
+`go vet` and `go test`.
 
 ## Configuration
 
@@ -77,6 +81,7 @@ jira:
   statuses:
     with_pr: "In Development"
     without_pr: "Ready"
+    merged_pr: "Done"
     abandoned: "Abandoned"
   users:                     # optional GitHub login -> JIRA user mapping
     github-login: "jira-email@company.com"

cmd/root.go

@@ -2,7 +2,9 @@
 package cmd
 
 import (
+	"context"
 	"fmt"
+	"io"
 	"log"
 	"os"
 	"strings"
@@ -19,8 +21,29 @@ var version = "dev"
 var (
 	dryRun bool
 	debug  bool
+
+	userConfigDir = os.UserConfigDir
+	loadConfig    = config.Load
+	newGitHub     = func(token string) githubClient {
+		return github.NewClient(token)
+	}
+	newJira = func(url, user, token string) (jiraClient, error) {
+		return jira.NewClient(url, user, token)
+	}
 )
 
+type githubClient interface {
+	FetchIssue(ctx context.Context, owner, repo string, number int) (*github.IssueInfo, error)
+	FetchPullRequest(ctx context.Context, owner, repo string, number int) (*github.PRInfo, error)
+}
+
+type jiraClient interface {
+	ResolveUser(query string) (jira.ResolvedUser, error)
+	FindExisting(project, repo string, number int, urls []string) ([]jira.FindResult, error)
+	UpdateDescription(issueKey, description string) error
+	CreateIssue(params jira.CreateParams) (*jira.CreatedIssue, error)
+}
+
 func init() {
 	rootCmd.Version = version
 	rootCmd.PersistentFlags().BoolVarP(&dryRun, "dry-run", "n", false,
@@ -82,13 +105,37 @@ func formatLink(l ghLink) string {
 	return fmt.Sprintf("Issue: %s", smartLink(l.URL))
 }
 
+// lineWriter wraps an io.Writer and remembers the first write error,
+// turning subsequent writes into no-ops. This avoids repetitive
+// per-line error checks when printing CLI output.
+type lineWriter struct {
+	w   io.Writer
+	err error
+}
+
+func (lw *lineWriter) printf(format string, args ...any) {
+	if lw.err != nil {
+		return
+	}
+	_, lw.err = fmt.Fprintf(lw.w, format+"\n", args...)
+}
+
+func (lw *lineWriter) writeErr() error {
+	if lw.err == nil {
+		return nil
+	}
+	return fmt.Errorf("writing output: %w", lw.err)
+}
+
 func run(cmd *cobra.Command, args []string) error {
-	configDir, err := os.UserConfigDir()
+	out := &lineWriter{w: cmd.OutOrStdout()}
+
+	configDir, err := userConfigDir()
 	if err != nil {
 		return fmt.Errorf("finding config directory: %w", err)
 	}
 
-	cfg, err := config.Load(configDir)
+	cfg, err := loadConfig(configDir)
 	if err != nil {
 		return fmt.Errorf("loading config: %w", err)
 	}
@@ -100,7 +147,7 @@ func run(cmd *cobra.Command, args []string) error {
 
 	debugf("parsed URL: %s/%s %s #%d", parsed.Owner, parsed.Repo, parsed.Kind, parsed.Number)
 
-	ghClient := github.NewClient(cfg.GitHub.Token)
+	ghClient := newGitHub(cfg.GitHub.Token)
 
 	var (
 		summary       string
@@ -206,7 +253,7 @@ func run(cmd *cobra.Command, args []string) error {
 	issueType := issuetype.Detect(labels, prTitle)
 	debugf("detected issue type: %s", issueType)
 
-	jiraClient, err := jira.NewClient(cfg.Jira.URL, cfg.Jira.User, cfg.Jira.Token)
+	jiraClient, err := newJira(cfg.Jira.URL, cfg.Jira.User, cfg.Jira.Token)
 	if err != nil {
 		return fmt.Errorf("creating JIRA client: %w", err)
 	}
@@ -267,17 +314,17 @@ func run(cmd *cobra.Command, args []string) error {
 		}
 
 		if dryRun {
-			fmt.Println("mode: dry-run")
+			out.printf("mode: dry-run")
 		} else {
-			fmt.Println("mode: update")
+			out.printf("mode: update")
 		}
 
 		for _, e := range workingSet {
-			fmt.Printf("existing: %s  %s\n", e.Key, e.URL)
-			fmt.Printf("summary: %s (unchanged)\n", e.Summary)
-			fmt.Printf("status: %s (unchanged)\n", e.Status)
+			out.printf("existing: %s  %s", e.Key, e.URL)
+			out.printf("summary: %s (unchanged)", e.Summary)
+			out.printf("status: %s (unchanged)", e.Status)
 			if e.Assignee != "" {
-				fmt.Printf("assignee: %s (unchanged)\n", e.Assignee)
+				out.printf("assignee: %s (unchanged)", e.Assignee)
 			}
 		}
 
@@ -301,9 +348,12 @@ func run(cmd *cobra.Command, args []string) error {
 				}
 				updatedDesc := e.Description + "\n" + strings.Join(newParts, "\n")
 
-				fmt.Println("adding missing links:")
+				out.printf("adding missing links:")
 				for _, l := range missingLinks {
-					fmt.Println(" ", l.URL)
+					out.printf("  %s", l.URL)
+				}
+				if err := out.writeErr(); err != nil {
+					return err
 				}
 				if !dryRun {
 					if err := jiraClient.UpdateDescription(e.Key, updatedDesc); err != nil {
@@ -312,7 +362,7 @@ func run(cmd *cobra.Command, args []string) error {
 				}
 			}
 		}
-		return nil
+		return out.writeErr()
 	}
 
 	// No existing issue found — create a new one
@@ -329,20 +379,23 @@ func run(cmd *cobra.Command, args []string) error {
 	debugf("target status: %s (prState=%s)", targetStatus, prState)
 
 	if dryRun {
-		fmt.Println("mode: dry-run")
+		out.printf("mode: dry-run")
 	} else {
-		fmt.Println("mode: create")
+		out.printf("mode: create")
 	}
 
-	fmt.Printf("project: %s\n", cfg.Jira.Project)
-	fmt.Printf("type: %s\n", issueType)
-	fmt.Printf("summary: %s\n", summary)
-	fmt.Printf("description: %s\n", description)
+	out.printf("project: %s", cfg.Jira.Project)
+	out.printf("type: %s", issueType)
+	out.printf("summary: %s", summary)
+	out.printf("description: %s", description)
 	if assignee.AccountID != "" {
-		fmt.Printf("assignee: %s\n", assignee.DisplayName)
+		out.printf("assignee: %s", assignee.DisplayName)
 	}
-	fmt.Printf("transition to: %s\n", targetStatus)
+	out.printf("transition to: %s", targetStatus)
 
+	if err := out.writeErr(); err != nil {
+		return err
+	}
 	if dryRun {
 		return nil
 	}
@@ -360,7 +413,7 @@ func run(cmd *cobra.Command, args []string) error {
 		return fmt.Errorf("creating JIRA issue: %w", err)
 	}
 
-	fmt.Printf("created: %s  %s\n", created.Key, created.URL)
+	out.printf("created: %s  %s", created.Key, created.URL)
 
-	return nil
+	return out.err
 }