refactor: remove stdin support, use {prompt} placeholder only

Author: JonCanning

README.md

@@ -53,8 +53,8 @@ issuebot --repo owner/repo --ntfy-topic my-alerts --command "copilot -p {prompt}
 # Log to a file for background operation
 issuebot --org myorg --log-file ~/.issuebot/issuebot.log --command "claude -p {prompt} --dangerously-skip-permissions"
 
-# Use any command that reads from stdin
-issuebot --local --command "./my-issue-handler.sh"
+# Use a custom script
+issuebot --local --command "./my-issue-handler.sh {prompt}"
 ```
 
 ### Flags
@@ -69,7 +69,7 @@ issuebot --local --command "./my-issue-handler.sh"
 | `--workers` | `5` | Max concurrent repo workers |
 | `--workspace` | `~/.issuebot/repos` | Directory for cloned repos |
 | `--local` | `false` | Use current directory instead of cloning |
-| `--command` | **(required)** | Command to run (prompt via stdin or `{prompt}` placeholder) |
+| `--command` | **(required)** | Command to run (`{prompt}` is replaced with the rendered prompt) |
 | `--prompt-file` | `~/.issuebot/prompt.tmpl` | Path to prompt template file |
 | `--dry-run` | `false` | Run command but skip push/PR (print diff instead) |
 | `--max-retries` | `3` | Max retry attempts per issue |
@@ -94,7 +94,7 @@ Each repo gets at most one concurrent worker to prevent conflicts. Failed issues
 
 The prompt template controls what your command receives as input. On first run, issuebot writes a default template to `~/.issuebot/prompt.tmpl`. Use `--prompt-file` to specify a different path.
 
-The template uses Go's [text/template](https://pkg.go.dev/text/template) syntax. The rendered output is passed to your `--command` via stdin (or substituted into `{prompt}`).
+The template uses Go's [text/template](https://pkg.go.dev/text/template) syntax. The rendered output replaces `{prompt}` in your `--command`.
 
 **Default template:**
 
@@ -133,7 +133,7 @@ The `ISSUE_FAILED` marker is important — if the command output contains it, is
 
 ## Command Interface
 
-The `--command` flag is required. By default, the prompt is passed via stdin. If your tool needs it as an argument, use `{prompt}` as a placeholder (stdin is not used when `{prompt}` is present):
+The `--command` flag is required. Use `{prompt}` as a placeholder — issuebot substitutes it with the rendered prompt template:
 
 ```bash
 # Claude Code
@@ -144,9 +144,6 @@ issuebot --command "copilot -p {prompt} --yolo"
 
 # Google Gemini CLI
 issuebot --command "gemini -p {prompt} --yolo"
-
-# Any tool that reads stdin
-issuebot --command "./my-issue-handler.sh"
 ```
 
 ## Per-Issue Configuration

cmd/watch.go

@@ -44,7 +44,7 @@ func init() {
 	f.StringVar(&cfg.Workspace, "workspace", cfg.Workspace, "Workspace directory for repo clones")
 	f.BoolVar(&cfg.Local, "local", cfg.Local, "Use current directory instead of cloning")
 	f.BoolVar(&cfg.DryRun, "dry-run", cfg.DryRun, "Run command but skip push/PR (print diff instead)")
-	f.StringVar(&cfg.Command, "command", cfg.Command, "Command to run (prompt via stdin or {prompt} placeholder)")
+	f.StringVar(&cfg.Command, "command", cfg.Command, "Command to run ({prompt} is replaced with the rendered prompt)")
 
 	_ = rootCmd.MarkFlagRequired("command")
 

internal/worker/worker.go

@@ -82,22 +82,12 @@ func (w *Worker) pullRepo(ctx context.Context, repoDir string) (string, error) {
 // If the command contains {prompt}, the prompt is substituted as an argument.
 // Otherwise, the prompt is passed via stdin.
 func (w *Worker) RunCommand(ctx context.Context, workDir, prompt string) (string, error) {
-	cmdStr := w.CLIConfig.Command
-
-	// If {prompt} placeholder is present, substitute it and don't pipe stdin.
-	useStdin := !strings.Contains(cmdStr, "{prompt}")
-	if !useStdin {
-		cmdStr = strings.ReplaceAll(cmdStr, "{prompt}", shellescape(prompt))
-	}
+	cmdStr := strings.ReplaceAll(w.CLIConfig.Command, "{prompt}", shellescape(prompt))
 
 	cmd := exec.CommandContext(ctx, "sh", "-c", cmdStr)
 	cmd.Dir = workDir
 	cmd.Stderr = os.Stderr
 
-	if useStdin {
-		cmd.Stdin = strings.NewReader(prompt)
-	}
-
 	out, err := cmd.Output()
 	if err != nil {
 		return "", fmt.Errorf("command exited with error: %w", err)

internal/worker/worker_test.go

@@ -21,6 +21,7 @@ import (
 
 const (
 	testIssueTitle = "Test issue"
+	testEchoCmd    = "echo {prompt}"
 )
 
 // mockCommand creates a shell script that echoes output and exits with the given code.
@@ -90,7 +91,7 @@ func testWorker(t *testing.T) *Worker {
 	return &Worker{
 		State:     st,
 		Notifier:  notify.New(""),
-		CLIConfig: config.CLIConfig{Strategy: "pr", MaxRetries: 3, Workspace: filepath.Join(dir, "repos"), PromptFile: promptFile, Command: "cat"},
+		CLIConfig: config.CLIConfig{Strategy: "pr", MaxRetries: 3, Workspace: filepath.Join(dir, "repos"), PromptFile: promptFile, Command: testEchoCmd},
 	}
 }
 
@@ -155,24 +156,24 @@ func TestWorker_RunCommand_Failure(t *testing.T) {
 	}
 }
 
-func TestWorker_RunCommand_Stdin(t *testing.T) {
+func TestWorker_RunCommand_PromptSubstitution(t *testing.T) {
 	w := testWorker(t)
-	w.CLIConfig.Command = "cat"
+	w.CLIConfig.Command = testEchoCmd
 	dir := t.TempDir()
 
-	result, err := w.RunCommand(context.Background(), dir, "hello from stdin")
+	result, err := w.RunCommand(context.Background(), dir, "hello world")
 	if err != nil {
 		t.Fatalf("unexpected error: %v", err)
 	}
 
-	if result != "hello from stdin" {
-		t.Errorf("result = %q, want %q", result, "hello from stdin")
+	if result != "hello world" {
+		t.Errorf("result = %q, want %q", result, "hello world")
 	}
 }
 
 func TestWorker_RunCommand_PromptPlaceholder(t *testing.T) {
 	w := testWorker(t)
-	w.CLIConfig.Command = "echo {prompt}"
+	w.CLIConfig.Command = testEchoCmd
 	dir := t.TempDir()
 
 	result, err := w.RunCommand(context.Background(), dir, "fix the bug")
@@ -187,7 +188,7 @@ func TestWorker_RunCommand_PromptPlaceholder(t *testing.T) {
 
 func TestWorker_RunCommand_PromptPlaceholder_QuotesHandled(t *testing.T) {
 	w := testWorker(t)
-	w.CLIConfig.Command = "echo {prompt}"
+	w.CLIConfig.Command = testEchoCmd
 	dir := t.TempDir()
 
 	result, err := w.RunCommand(context.Background(), dir, "it's a test")