feat(01-03): add deterministic rich CLI output

- Inject bonfire.Output from stdin/stdout/stderr with stdlib widgets and x/term
- Degrade spinner, progress, table and prompts without a TTY or color
- Reject plugin command names that are not namespace:verb

bonfire/command.go

@@ -2,12 +2,15 @@ package bonfire
 
 import (
 	"context"
-	"fmt"
+	"errors"
-	"io"
+	"strings"
 
 	"github.com/spf13/cobra"
 )
 
+// ErrCommandName is returned when a plugin command is missing namespace:verb.
+var ErrCommandName = errors.New("bonfire: plugin command name must be namespace:verb")
+
 // Command is a console command value collected from plugins or the tool.
 type Command struct {
 	Name        string
@@ -39,13 +42,6 @@ type Input interface {
 	Flag(name string) (string, bool)
 }
 
-// Output is an injected writer used by commands instead of package-level stdout.
-type Output interface {
-	io.Writer
-	Println(a ...any)
-	Printf(format string, a ...any)
-}
-
 type cobraInput struct {
 	cmd  *cobra.Command
 	spec Command
@@ -84,27 +80,39 @@ func (in cobraInput) Flag(name string) (string, bool) {
 	return val, true
 }
 
-type writerOutput struct {
+func validCommandName(name string) bool {
-	w io.Writer
+	switch name {
+	case "build", "dev":
+		return true
+	}
+	ns, verb, ok := strings.Cut(name, ":")
+	return ok && ns != "" && verb != "" && !strings.Contains(verb, " ")
 }
 
-func (o writerOutput) Write(p []byte) (int, error) {
+func commandUsage(c Command) string {
-	if o.w == nil {
+	parts := []string{c.Name}
-		return 0, io.ErrClosedPipe
+	for _, a := range c.Args {
+		if a.Required {
+			parts = append(parts, "<"+a.Name+">")
+		} else {
+			parts = append(parts, "["+a.Name+"]")
+		}
 	}
-	return o.w.Write(p)
+	return strings.Join(parts, " ")
 }
 
-func (o writerOutput) Println(a ...any) {
+func positionalArgs(args []Arg) cobra.PositionalArgs {
-	if o.w == nil {
+	required := 0
-		return
+	for _, a := range args {
+		if a.Required {
+			required++
+		}
 	}
-	fmt.Fprintln(o.w, a...)
+	if required == 0 {
-}
+		return cobra.ArbitraryArgs
-
-func (o writerOutput) Printf(format string, a ...any) {
-	if o.w == nil {
-		return
 	}
-	fmt.Fprintf(o.w, format, a...)
+	if required == len(args) {
+		return cobra.ExactArgs(required)
+	}
+	return cobra.MinimumNArgs(required)
 }

bonfire/output.go

@@ -0,0 +1,170 @@
+package bonfire
+
+import (
+	"fmt"
+	"io"
+	"os"
+
+	"golang.org/x/term"
+)
+
+const (
+	ansiReset  = "\x1b[0m"
+	ansiRed    = "\x1b[31m"
+	ansiGreen  = "\x1b[32m"
+	ansiYellow = "\x1b[33m"
+	ansiCyan   = "\x1b[36m"
+	ansiDim    = "\x1b[90m"
+
+	symCheck  = "✓"
+	symCross  = "✗"
+	symWarn   = "⚠"
+	symInfo   = "ℹ"
+	symArrow  = "→"
+	symPrompt = "?"
+)
+
+// Output is the injected console used by commands. Tests supply streams.
+type Output interface {
+	io.Writer
+	Println(a ...any)
+	Printf(format string, a ...any)
+	Info(message string)
+	Success(message string)
+	Error(message string)
+	Warning(message string)
+	Table(headers []string, rows [][]string)
+	Spinner(message string, fn func() error) error
+	Progress(total int, fn func(Progress) error) error
+	Ask(question, def string) (string, error)
+	Confirm(question string, def bool) (bool, error)
+	Choice(question string, choices []string, def int) (string, error)
+	Secret(question string) (string, error)
+}
+
+// Progress is a single progress bar advanced from a command.
+type Progress interface {
+	Advance(step int)
+}
+
+type console struct {
+	in          io.Reader
+	out         io.Writer
+	err         io.Writer
+	lookup      func(string) string
+	tty         bool
+	interactive bool
+	color       bool
+}
+
+// NewOutput builds Output from injected streams and the process color policy.
+func NewOutput(in io.Reader, out, errW io.Writer) Output {
+	return newConsole(in, out, errW, os.Getenv, nil, nil)
+}
+
+func newConsole(in io.Reader, out, errW io.Writer, lookup func(string) string, tty, interactive *bool) *console {
+	if in == nil {
+		in = os.Stdin
+	}
+	if out == nil {
+		out = os.Stdout
+	}
+	if errW == nil {
+		errW = out
+	}
+	if lookup == nil {
+		lookup = os.Getenv
+	}
+	c := &console{in: in, out: out, err: errW, lookup: lookup}
+	if tty != nil {
+		c.tty = *tty
+	} else {
+		c.tty = isTerminal(out)
+	}
+	if interactive != nil {
+		c.interactive = *interactive
+	} else {
+		c.interactive = isTerminal(in) && c.tty
+	}
+	c.color = supportsColor(lookup, c.tty)
+	return c
+}
+
+func supportsColor(lookup func(string) string, tty bool) bool {
+	if lookup == nil {
+		lookup = os.Getenv
+	}
+	if lookup("NO_COLOR") != "" || lookup("TERM") == "dumb" {
+		return false
+	}
+	if lookup("FORCE_COLOR") != "" {
+		return true
+	}
+	return tty
+}
+
+func isTerminal(rw any) bool {
+	type fd interface{ Fd() uintptr }
+	f, ok := rw.(fd)
+	if !ok {
+		return false
+	}
+	return term.IsTerminal(int(f.Fd()))
+}
+
+func (c *console) Write(p []byte) (int, error) {
+	if c.out == nil {
+		return 0, io.ErrClosedPipe
+	}
+	return c.out.Write(p)
+}
+
+func (c *console) Println(a ...any) {
+	if c.out == nil {
+		return
+	}
+	fmt.Fprintln(c.out, a...)
+}
+
+func (c *console) Printf(format string, a ...any) {
+	if c.out == nil {
+		return
+	}
+	fmt.Fprintf(c.out, format, a...)
+}
+
+func (c *console) Info(message string) {
+	c.Println(c.style(ansiCyan, symInfo) + " " + message)
+}
+
+func (c *console) Success(message string) {
+	c.Println(c.style(ansiGreen, symCheck) + " " + message)
+}
+
+func (c *console) Error(message string) {
+	w := c.err
+	if w == nil {
+		w = c.out
+	}
+	if w == nil {
+		return
+	}
+	fmt.Fprintln(w, c.style(ansiRed, symCross)+" "+message)
+}
+
+func (c *console) Warning(message string) {
+	c.Println(c.style(ansiYellow, symWarn) + " " + message)
+}
+
+func (c *console) style(code, s string) string {
+	if !c.color {
+		return s
+	}
+	return code + s + ansiReset
+}
+
+func (c *console) dim(s string) string {
+	return c.style(ansiDim, s)
+}
+
+func boolPtr(v bool) *bool { return &v }

bonfire/output_test.go

@@ -0,0 +1,157 @@
+package bonfire
+
+import (
+	"bytes"
+	"errors"
+	"strings"
+	"testing"
+)
+
+func TestNonTTYSpinner(t *testing.T) {
+	var buf bytes.Buffer
+	out := NewOutput(strings.NewReader(""), &buf, &buf)
+	if err := out.Spinner("building", func() error { return nil }); err != nil {
+		t.Fatal(err)
+	}
+	if got := buf.String(); got != "[...] building\n" {
+		t.Fatalf("spinner = %q", got)
+	}
+}
+
+func TestNonTTYProgress(t *testing.T) {
+	var buf bytes.Buffer
+	out := NewOutput(strings.NewReader(""), &buf, &buf)
+	if err := out.Progress(10, func(p Progress) error {
+		for i := 0; i < 10; i++ {
+			p.Advance(1)
+		}
+		return nil
+	}); err != nil {
+		t.Fatal(err)
+	}
+	got := buf.String()
+	for _, want := range []string{"[1/10] 10%", "[5/10] 50%", "[10/10] 100%"} {
+		if !strings.Contains(got, want) {
+			t.Fatalf("missing %q in %q", want, got)
+		}
+	}
+	if strings.Contains(got, "\x1b[") {
+		t.Fatalf("non-tty progress has ansi: %q", got)
+	}
+}
+
+func TestNonTTYTable(t *testing.T) {
+	var buf bytes.Buffer
+	out := NewOutput(strings.NewReader(""), &buf, &buf)
+	out.Table([]string{"plugin", "status"}, [][]string{{"golem15.blog", "active"}})
+	got := buf.String()
+	if got != "plugin\tstatus\ngolem15.blog\tactive\n" {
+		t.Fatalf("table = %q", got)
+	}
+}
+
+func TestColorPolicy(t *testing.T) {
+	t.Run("NO_COLOR", func(t *testing.T) {
+		var buf bytes.Buffer
+		out := newConsole(strings.NewReader(""), &buf, &buf, func(k string) string {
+			if k == "NO_COLOR" {
+				return "1"
+			}
+			if k == "FORCE_COLOR" {
+				return "1"
+			}
+			return ""
+		}, boolPtr(true), boolPtr(true))
+		out.Success("ok")
+		if strings.Contains(buf.String(), "\x1b[") {
+			t.Fatalf("NO_COLOR leaked ansi: %q", buf.String())
+		}
+	})
+	t.Run("TERM=dumb", func(t *testing.T) {
+		var buf bytes.Buffer
+		out := newConsole(strings.NewReader(""), &buf, &buf, func(k string) string {
+			if k == "TERM" {
+				return "dumb"
+			}
+			if k == "FORCE_COLOR" {
+				return "1"
+			}
+			return ""
+		}, boolPtr(true), boolPtr(true))
+		out.Info("hi")
+		if strings.Contains(buf.String(), "\x1b[") {
+			t.Fatalf("TERM=dumb leaked ansi: %q", buf.String())
+		}
+	})
+	t.Run("FORCE_COLOR", func(t *testing.T) {
+		var buf bytes.Buffer
+		out := newConsole(strings.NewReader(""), &buf, &buf, func(k string) string {
+			if k == "FORCE_COLOR" {
+				return "1"
+			}
+			return ""
+		}, boolPtr(false), boolPtr(false))
+		out.Success("ok")
+		if !strings.Contains(buf.String(), "\x1b[") {
+			t.Fatalf("FORCE_COLOR did not enable ansi: %q", buf.String())
+		}
+	})
+	t.Run("default non-tty", func(t *testing.T) {
+		var buf bytes.Buffer
+		out := NewOutput(strings.NewReader(""), &buf, &buf)
+		out.Success("ok")
+		if strings.Contains(buf.String(), "\x1b[") {
+			t.Fatalf("non-tty default has ansi: %q", buf.String())
+		}
+	})
+}
+
+func TestPluginCommandRequiresColon(t *testing.T) {
+	var buf bytes.Buffer
+	_, err := NewRoot("app", []Command{{Name: "hello", Description: "bad"}}, &buf)
+	if err == nil || !errors.Is(err, ErrCommandName) {
+		t.Fatalf("want ErrCommandName, got %v", err)
+	}
+	if !strings.Contains(err.Error(), "hello") {
+		t.Fatalf("error should name the command: %v", err)
+	}
+}
+
+func TestKernelAndNamespacedCommands(t *testing.T) {
+	var buf bytes.Buffer
+	root, err := NewRoot("summer", []Command{
+		{Name: "build", Description: "Build the app"},
+		{Name: "dev", Description: "Watch and rebuild"},
+		{Name: "make:plugin", Description: "Scaffold a plugin from a vendor.plugin id"},
+		{Name: "greeter:hello", Description: "Say hello"},
+	}, &buf)
+	if err != nil {
+		t.Fatal(err)
+	}
+	root.SetArgs([]string{"make:plugin", "--help"})
+	if err := root.Execute(); err != nil {
+		t.Fatal(err)
+	}
+	if !strings.Contains(buf.String(), "vendor.plugin") && !strings.Contains(buf.String(), "make:plugin") {
+		t.Fatalf("help = %q", buf.String())
+	}
+}
+
+func TestHelpUsesSharedAdapter(t *testing.T) {
+	var buf bytes.Buffer
+	root, err := NewRoot("hello", []Command{{
+		Name:        "greeter:hello",
+		Description: "Print the configured application name",
+	}}, &buf)
+	if err != nil {
+		t.Fatal(err)
+	}
+	root.SetArgs([]string{"greeter:hello", "--help"})
+	if err := root.Execute(); err != nil {
+		t.Fatal(err)
+	}
+	got := buf.String()
+	if !strings.Contains(got, "greeter:hello") || !strings.Contains(got, "Print the configured application name") {
+		t.Fatalf("help = %q", got)
+	}
+}

bonfire/prompts.go

@@ -0,0 +1,133 @@
+package bonfire
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+
+	"golang.org/x/term"
+)
+
+func (c *console) Ask(question, def string) (string, error) {
+	c.writeQuestion(question, def)
+	line, err := c.readLine()
+	if err != nil {
+		if err == io.EOF {
+			return def, nil
+		}
+		return "", err
+	}
+	if line == "" {
+		return def, nil
+	}
+	return line, nil
+}
+
+func (c *console) Confirm(question string, def bool) (bool, error) {
+	if !c.interactive {
+		return def, nil
+	}
+	hint := "y/N"
+	if def {
+		hint = "Y/n"
+	}
+	line, err := c.Ask(question+" ["+hint+"]", "")
+	if err != nil {
+		return false, err
+	}
+	if line == "" {
+		return def, nil
+	}
+	switch strings.ToLower(line) {
+	case "y", "yes":
+		return true, nil
+	case "n", "no":
+		return false, nil
+	default:
+		return def, nil
+	}
+}
+
+func (c *console) Choice(question string, choices []string, def int) (string, error) {
+	if len(choices) == 0 {
+		return "", fmt.Errorf("bonfire: choice has no options")
+	}
+	if def < 0 || def >= len(choices) {
+		def = 0
+	}
+	c.Println(c.style(ansiCyan, symPrompt) + " " + question)
+	for i, choice := range choices {
+		mark := " "
+		if i == def {
+			mark = "*"
+		}
+		c.Printf("  %s %d) %s\n", mark, i+1, choice)
+	}
+	line, err := c.readLine()
+	if err != nil {
+		if err == io.EOF {
+			return choices[def], nil
+		}
+		return "", err
+	}
+	if line == "" {
+		return choices[def], nil
+	}
+	n, convErr := strconv.Atoi(line)
+	if convErr != nil || n < 1 || n > len(choices) {
+		return choices[def], nil
+	}
+	return choices[n-1], nil
+}
+
+// Secret reads a hidden password on a TTY via term.ReadPassword.
+// When stdin is not a terminal it reads a plain line and never logs the value.
+func (c *console) Secret(question string) (string, error) {
+	c.writeQuestion(question, "")
+	if f, ok := c.in.(*os.File); ok && term.IsTerminal(int(f.Fd())) {
+		b, err := term.ReadPassword(int(f.Fd()))
+		c.Println()
+		if err != nil {
+			return "", err
+		}
+		return string(b), nil
+	}
+	line, err := c.readLine()
+	if err != nil {
+		if err == io.EOF {
+			return "", nil
+		}
+		return "", err
+	}
+	return line, nil
+}
+
+func (c *console) writeQuestion(question, def string) {
+	suffix := ""
+	if def != "" {
+		suffix = " " + c.dim("("+def+")")
+	}
+	c.Printf("%s %s%s %s ", c.style(ansiCyan, symPrompt), question, suffix, symArrow)
+}
+
+func (c *console) readLine() (string, error) {
+	if c.in == nil {
+		return "", io.EOF
+	}
+	reader, ok := c.in.(*bufio.Reader)
+	if !ok {
+		reader = bufio.NewReader(c.in)
+	}
+	line, err := reader.ReadString('\n')
+	line = strings.TrimRight(line, "\r\n")
+	if err != nil && err != io.EOF {
+		return "", err
+	}
+	if err == io.EOF && line == "" {
+		return "", io.EOF
+	}
+	return strings.TrimSpace(line), nil
+}

bonfire/prompts_test.go

@@ -0,0 +1,92 @@
+package bonfire
+
+import (
+	"bytes"
+	"io"
+	"strings"
+	"testing"
+)
+
+func TestConfirmUsesDefaultWhenNonTTY(t *testing.T) {
+	var buf bytes.Buffer
+	out := NewOutput(strings.NewReader("n\n"), &buf, &buf)
+	got, err := out.Confirm("continue?", true)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !got {
+		t.Fatal("non-tty confirm should use default true without reading stdin")
+	}
+	if buf.Len() != 0 {
+		t.Fatalf("confirm wrote %q", buf.String())
+	}
+}
+
+func TestAskReadsStdinLine(t *testing.T) {
+	var buf bytes.Buffer
+	out := NewOutput(strings.NewReader("alice\n"), &buf, &buf)
+	got, err := out.Ask("name", "bob")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != "alice" {
+		t.Fatalf("ask = %q", got)
+	}
+}
+
+func TestAskEOFUsesDefault(t *testing.T) {
+	var buf bytes.Buffer
+	out := NewOutput(strings.NewReader(""), &buf, &buf)
+	got, err := out.Ask("name", "bob")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != "bob" {
+		t.Fatalf("ask eof = %q", got)
+	}
+}
+
+func TestChoiceReadsStdinLine(t *testing.T) {
+	var buf bytes.Buffer
+	out := NewOutput(strings.NewReader("2\n"), &buf, &buf)
+	got, err := out.Choice("pick", []string{"a", "b", "c"}, 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != "b" {
+		t.Fatalf("choice = %q", got)
+	}
+}
+
+func TestSecretReadsPlainStdinLine(t *testing.T) {
+	var buf bytes.Buffer
+	out := NewOutput(strings.NewReader("s3cret\n"), &buf, &buf)
+	got, err := out.Secret("token")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != "s3cret" {
+		t.Fatalf("secret = %q", got)
+	}
+	if strings.Contains(buf.String(), "s3cret") {
+		t.Fatal("secret value was written to output")
+	}
+}
+
+func TestClosedStdinDoesNotHang(t *testing.T) {
+	var buf bytes.Buffer
+	out := NewOutput(io.NopCloser(strings.NewReader("")), &buf, &buf)
+	if _, err := out.Ask("name", "def"); err != nil {
+		t.Fatal(err)
+	}
+	ok, err := out.Confirm("ok?", false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if ok {
+		t.Fatal("confirm default false")
+	}
+	if _, err := out.Secret("pw"); err != nil {
+		t.Fatal(err)
+	}
+}

bonfire/root.go

@@ -1,6 +1,7 @@
 package bonfire
 
 import (
+	"fmt"
 	"io"
 	"os"
 
@@ -9,10 +10,22 @@ import (
 
 // NewRoot builds the shared cobra root used by the summer tool and app binaries.
 // It accepts command values rather than a party registry to avoid an import cycle.
-func NewRoot(name string, commands []Command, out io.Writer) *cobra.Command {
+func NewRoot(name string, commands []Command, out io.Writer) (*cobra.Command, error) {
+	return NewRootIO(name, commands, os.Stdin, out, out)
+}
+
+// NewRootIO is NewRoot with injected stdin/stdout/stderr for tests.
+func NewRootIO(name string, commands []Command, in io.Reader, out, errW io.Writer) (*cobra.Command, error) {
 	if out == nil {
 		out = os.Stdout
 	}
+	if errW == nil {
+		errW = out
+	}
+	if in == nil {
+		in = os.Stdin
+	}
+	output := NewOutput(in, out, errW)
 	root := &cobra.Command{
 		Use:           name,
 		SilenceUsage:  true,
@@ -21,30 +34,32 @@ func NewRoot(name string, commands []Command, out io.Writer) *cobra.Command {
 			DisableDefaultCmd: true,
 		},
 	}
+	root.SetIn(in)
 	root.SetOut(out)
-	root.SetErr(out)
+	root.SetErr(errW)
 	for _, command := range commands {
-		root.AddCommand(wrap(command, out))
+		cmd, err := wrap(command, output)
+		if err != nil {
+			return nil, err
+		}
+		root.AddCommand(cmd)
 	}
-	return root
+	return root, nil
 }
 
-func wrap(c Command, out io.Writer) *cobra.Command {
+func wrap(c Command, out Output) (*cobra.Command, error) {
+	if !validCommandName(c.Name) {
+		return nil, fmt.Errorf("%w: %q", ErrCommandName, c.Name)
+	}
 	cmd := &cobra.Command{
-		Use:   c.Name,
+		Use:   commandUsage(c),
 		Short: c.Description,
-		Args:  cobra.ArbitraryArgs,
+		Args:  positionalArgs(c.Args),
 		RunE: func(cmd *cobra.Command, args []string) error {
 			if c.Run == nil {
 				return nil
 			}
-			writer := out
+			return c.Run(cmd.Context(), cobraInput{cmd: cmd, spec: c, args: args}, out)
-			if cmd != nil {
-				if w := cmd.OutOrStdout(); w != nil {
-					writer = w
-				}
-			}
-			return c.Run(cmd.Context(), cobraInput{cmd: cmd, spec: c, args: args}, writerOutput{w: writer})
 		},
 	}
 	for _, flag := range c.Flags {
@@ -54,5 +69,5 @@ func wrap(c Command, out io.Writer) *cobra.Command {
 		}
 		cmd.Flags().String(flag.Name, flag.Default, flag.Description)
 	}
-	return cmd
+	return cmd, nil
 }

bonfire/widgets.go

@@ -0,0 +1,210 @@
+package bonfire
+
+import (
+	"fmt"
+	"strings"
+	"sync"
+	"time"
+	"unicode/utf8"
+)
+
+var spinnerFrames = []rune{'⠋', '⠙', '⠹', '⠸', '⠼', '⠴', '⠦', '⠧', '⠇', '⠏'}
+
+const (
+	boxTopLeft     = "┌"
+	boxTopRight    = "┐"
+	boxBottomLeft  = "└"
+	boxBottomRight = "┘"
+	boxHorizontal  = "─"
+	boxVertical    = "│"
+	boxTeeRight    = "├"
+	boxTeeLeft     = "┤"
+	boxTeeDown     = "┬"
+	boxTeeUp       = "┴"
+	boxCross       = "┼"
+)
+
+func (c *console) Spinner(message string, fn func() error) error {
+	if fn == nil {
+		fn = func() error { return nil }
+	}
+	if !c.tty {
+		c.Printf("[...] %s\n", message)
+		return fn()
+	}
+
+	done := make(chan struct{})
+	var wg sync.WaitGroup
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		i := 0
+		ticker := time.NewTicker(80 * time.Millisecond)
+		defer ticker.Stop()
+		c.Printf("\r%s %s", c.style(ansiCyan, string(spinnerFrames[0])), message)
+		for {
+			select {
+			case <-done:
+				return
+			case <-ticker.C:
+				i++
+				frame := spinnerFrames[i%len(spinnerFrames)]
+				c.Printf("\r%s %s", c.style(ansiCyan, string(frame)), message)
+			}
+		}
+	}()
+
+	err := fn()
+	close(done)
+	wg.Wait()
+	if err != nil {
+		c.Printf("\r%s %s\n", c.style(ansiRed, symCross), message)
+		return err
+	}
+	c.Printf("\r%s %s\n", c.style(ansiGreen, symCheck), message)
+	return nil
+}
+
+func (c *console) Progress(total int, fn func(Progress) error) error {
+	if total < 1 {
+		total = 1
+	}
+	bar := &progressBar{c: c, total: total, lastPct: -1}
+	if fn == nil {
+		return nil
+	}
+	err := fn(bar)
+	if c.tty && bar.current >= bar.total {
+		c.Println()
+	}
+	return err
+}
+
+type progressBar struct {
+	c       *console
+	total   int
+	current int
+	lastPct int
+}
+
+func (p *progressBar) Advance(step int) {
+	if step < 1 {
+		step = 1
+	}
+	p.current += step
+	if p.current > p.total {
+		p.current = p.total
+	}
+	pct := 0
+	if p.total > 0 {
+		pct = p.current * 100 / p.total
+	}
+	if p.c.tty {
+		p.renderTTY(pct)
+		return
+	}
+	if p.lastPct >= 0 && pct/10 == p.lastPct/10 && pct != 100 {
+		return
+	}
+	if pct == 0 && p.lastPct < 0 {
+		p.lastPct = 0
+		return
+	}
+	if pct%10 == 0 || pct == 100 {
+		p.c.Printf("[%d/%d] %d%%\n", p.current, p.total, pct)
+		p.lastPct = pct
+	}
+}
+
+func (p *progressBar) renderTTY(pct int) {
+	width := 40
+	filled := 0
+	if p.total > 0 {
+		filled = p.current * width / p.total
+	}
+	if filled > width {
+		filled = width
+	}
+	bar := strings.Repeat("█", filled) + strings.Repeat(" ", width-filled)
+	color := progressColor(pct)
+	p.c.Printf("\r %s %5.1f%% %d/%d", p.c.style(color, bar), float64(pct), p.current, p.total)
+}
+
+func progressColor(pct int) string {
+	switch {
+	case pct >= 100:
+		return "\x1b[38;5;34m"
+	case pct >= 50:
+		return "\x1b[38;5;36m"
+	default:
+		return "\x1b[38;5;37m"
+	}
+}
+
+func (c *console) Table(headers []string, rows [][]string) {
+	if !c.tty {
+		c.Println(strings.Join(headers, "\t"))
+		for _, row := range rows {
+			c.Println(strings.Join(padRow(row, len(headers)), "\t"))
+		}
+		return
+	}
+	cols := len(headers)
+	all := make([][]string, 0, 1+len(rows))
+	all = append(all, headers)
+	for _, row := range rows {
+		all = append(all, padRow(row, cols))
+	}
+	widths := make([]int, cols)
+	for _, row := range all {
+		for i, cell := range row {
+			if n := utf8.RuneCountInString(cell); n > widths[i] {
+				widths[i] = n
+			}
+		}
+	}
+	c.Println(boxLine(widths, boxTopLeft, boxTeeDown, boxTopRight))
+	c.Println(boxRow(headers, widths, true, c))
+	c.Println(boxLine(widths, boxTeeRight, boxCross, boxTeeLeft))
+	for _, row := range rows {
+		c.Println(boxRow(padRow(row, cols), widths, false, c))
+	}
+	c.Println(boxLine(widths, boxBottomLeft, boxTeeUp, boxBottomRight))
+}
+
+func padRow(row []string, n int) []string {
+	out := make([]string, n)
+	for i := 0; i < n; i++ {
+		if i < len(row) {
+			out[i] = row[i]
+		}
+	}
+	return out
+}
+
+func boxLine(widths []int, left, mid, right string) string {
+	var b strings.Builder
+	b.WriteString(left)
+	for i, w := range widths {
+		if i > 0 {
+			b.WriteString(mid)
+		}
+		b.WriteString(strings.Repeat(boxHorizontal, w+2))
+	}
+	b.WriteString(right)
+	return b.String()
+}
+
+func boxRow(cells []string, widths []int, header bool, c *console) string {
+	var b strings.Builder
+	b.WriteString(boxVertical)
+	for i, cell := range cells {
+		pad := widths[i] - utf8.RuneCountInString(cell)
+		text := cell
+		if header {
+			text = c.style("\x1b[1m", cell)
+		}
+		fmt.Fprintf(&b, " %s%s %s", text, strings.Repeat(" ", pad), boxVertical)
+	}
+	return b.String()
+}

cmd/summer/main.go

@@ -10,7 +10,11 @@ import (
 )
 
 func main() {
-	root := bonfire.NewRoot("summer", toolCommands(), os.Stdout)
+	root, err := bonfire.NewRoot("summer", toolCommands(), os.Stdout)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
 	root.SetArgs(os.Args[1:])
 	if err := root.Execute(); err != nil {
 		fmt.Fprintln(os.Stderr, err)

cmd/summer/main_test.go

@@ -26,7 +26,10 @@ func TestToolCommandNames(t *testing.T) {
 	}
 
 	var buf bytes.Buffer
-	root := bonfire.NewRoot("summer", toolCommands(), &buf)
+	root, err := bonfire.NewRoot("summer", toolCommands(), &buf)
+	if err != nil {
+		t.Fatal(err)
+	}
 	root.SetArgs([]string{"make:plugin", "--help"})
 	if err := root.Execute(); err != nil {
 		t.Fatal(err)

examples/hello/hello_test.go

@@ -18,17 +18,13 @@ import (
 func TestGreeterHelloPrintsLayeredConfig(t *testing.T) {
 	got := runHello(t, nil)
 	want := "name=hello-app posts_per_page=10 debug=false extra=hello-from-optional events=ok collected=greeter handled=true"
-	if got != want {
+	assertGreeting(t, got, want)
-		t.Fatalf("output = %q, want %q", got, want)
-	}
 }
 
 func TestGreeterHelloSeesDevelopmentOverlay(t *testing.T) {
 	got := runHello(t, map[string]string{"SUMMER_ENV": "development"})
 	want := "name=hello-dev posts_per_page=10 debug=true extra=hello-from-optional events=ok collected=greeter handled=true"
-	if got != want {
+	assertGreeting(t, got, want)
-		t.Fatalf("output = %q, want %q", got, want)
-	}
 }
 
 func TestGreeterHelloSeesEnvVarOverrideOfPluginDefault(t *testing.T) {
@@ -36,9 +32,7 @@ func TestGreeterHelloSeesEnvVarOverrideOfPluginDefault(t *testing.T) {
 		"SUMMER_GOLEM15__HELLO__POSTS_PER_PAGE": "25",
 	})
 	want := "name=hello-app posts_per_page=25 debug=false extra=hello-from-optional events=ok collected=greeter handled=true"
-	if got != want {
+	assertGreeting(t, got, want)
-		t.Fatalf("output = %q, want %q", got, want)
-	}
 }
 
 func runHello(t *testing.T, env map[string]string) string {
@@ -56,9 +50,7 @@ func runHello(t *testing.T, env map[string]string) string {
 func TestGreeterRunsWithoutOptionalPlugin(t *testing.T) {
 	got := runHelloIDs(t, []string{"golem15.hello", "golem15.greeter"}, nil)
 	want := "name=hello-app posts_per_page=10 debug=false extra= events=ok collected=greeter handled=true"
-	if got != want {
+	assertGreeting(t, got, want)
-		t.Fatalf("output = %q, want %q", got, want)
-	}
 }
 
 func runHelloIDs(t *testing.T, ids []string, env map[string]string) string {
@@ -82,7 +74,10 @@ func runHelloIDs(t *testing.T, ids []string, env map[string]string) string {
 		}
 	}
 	var buf bytes.Buffer
-	root := bonfire.NewRoot("hello", commands, &buf)
+	root, err := bonfire.NewRoot("hello", commands, &buf)
+	if err != nil {
+		t.Fatalf("NewRoot: %v", err)
+	}
 	root.SetArgs([]string{"greeter:hello"})
 	if err := root.Execute(); err != nil {
 		t.Fatalf("execute: %v", err)
@@ -104,9 +99,27 @@ func TestBuiltBinaryGreeterHello(t *testing.T) {
 	if err != nil {
 		t.Fatalf("bin/hello greeter:hello: %v\n%s", err, out)
 	}
-	if got := strings.TrimSpace(string(out)); got != "name=hello-app posts_per_page=10 debug=false extra=hello-from-optional events=ok collected=greeter handled=true" {
+	got := strings.TrimSpace(string(out))
-		t.Fatalf("output = %q, want layered production config with optional extra and events", got)
+	want := "name=hello-app posts_per_page=10 debug=false extra=hello-from-optional events=ok collected=greeter handled=true"
+	assertGreeting(t, got, want)
+}
+
+func assertGreeting(t *testing.T, got, want string) {
+	t.Helper()
+	if !strings.Contains(got, "plugin\tstatus") || !strings.Contains(got, "golem15.greeter\tactive") {
+		t.Fatalf("missing non-tty table:\n%s", got)
 	}
+	if lastLine(got) != want {
+		t.Fatalf("greeting = %q, want %q\nfull:\n%s", lastLine(got), want, got)
+	}
+}
+
+func lastLine(s string) string {
+	s = strings.TrimSpace(s)
+	if i := strings.LastIndex(s, "\n"); i >= 0 {
+		return s[i+1:]
+	}
+	return s
 }
 
 func runSummerBuild(t *testing.T) string {

examples/hello/main.go

@@ -37,7 +37,10 @@ func run(args []string, out io.Writer) error {
 			commands = append(commands, hasCommands.Commands()...)
 		}
 	}
-	root := bonfire.NewRoot("hello", commands, out)
+	root, err := bonfire.NewRoot("hello", commands, out)
+	if err != nil {
+		return err
+	}
 	root.SetArgs(args)
 	return root.Execute()
 }

examples/hello/plugins/greeter/plugin.go

@@ -82,6 +82,10 @@ func (p *Plugin) Commands() []bonfire.Command {
 				}
 				handled = ok
 			}
+			out.Table([]string{"plugin", "status"}, [][]string{{"golem15.greeter", "active"}})
+			if _, err := out.Confirm("show greeting?", true); err != nil {
+				return err
+			}
 			out.Printf("name=%s posts_per_page=%d debug=%t extra=%s events=%s collected=%s handled=%t\n", name, posts, debug, p.extra, events, collected, handled)
 			return nil
 		},

examples/hello/plugins/greeter/plugin_test.go

@@ -3,8 +3,6 @@ package greeter
 import (
 	"bytes"
 	"context"
-	"fmt"
-	"io"
 	"os"
 	"strings"
 	"testing"
@@ -15,17 +13,6 @@ import (
 	"git.golem15.com/golem15/summercms/pact"
 )
 
-type testOut struct{ bytes.Buffer }
-
-func (o *testOut) Write(p []byte) (int, error) { return o.Buffer.Write(p) }
-func (o *testOut) Println(a ...any)            { fmt.Fprintln(&o.Buffer, a...) }
-func (o *testOut) Printf(format string, a ...any) {
-	fmt.Fprintf(&o.Buffer, format, a...)
-}
-
-var _ bonfire.Output = (*testOut)(nil)
-var _ io.Writer = (*testOut)(nil)
-
 type extraMsg struct{ msg string }
 
 func (e extraMsg) Message() string { return e.msg }
@@ -78,9 +65,10 @@ func runHelloCmd(t *testing.T, p *Plugin) string {
 	if len(cmds) == 0 {
 		t.Fatal("no commands")
 	}
-	var out testOut
+	var buf bytes.Buffer
-	if err := cmds[0].Run(context.Background(), nil, &out); err != nil {
+	out := bonfire.NewOutput(strings.NewReader(""), &buf, &buf)
+	if err := cmds[0].Run(context.Background(), nil, out); err != nil {
 		t.Fatalf("Run: %v", err)
 	}
-	return strings.TrimSpace(out.String())
+	return strings.TrimSpace(buf.String())
 }

go.mod

@@ -11,6 +11,7 @@ require (
 	github.com/knadh/koanf/providers/file v1.2.1
 	github.com/knadh/koanf/v2 v2.3.6
 	github.com/spf13/cobra v1.10.2
+	golang.org/x/term v0.46.0
 )
 
 require (
@@ -22,5 +23,5 @@ require (
 	github.com/mitchellh/reflectwalk v1.0.2 // indirect
 	github.com/spf13/pflag v1.0.9 // indirect
 	go.yaml.in/yaml/v3 v3.0.4 // indirect
-	golang.org/x/sys v0.32.0 // indirect
+	golang.org/x/sys v0.48.0 // indirect
 )

go.sum

@@ -38,8 +38,10 @@ github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcU
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 go.yaml.in/yaml/v3 v3.0.4 h1:tfq32ie2Jv2UxXFdLJdh3jXuOzWiL1fo0bu/FbuKpbc=
 go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
-golang.org/x/sys v0.32.0 h1:s77OFDvIQeibCmezSnk/q6iAfkdiQaJi4VzroCFrN20=
+golang.org/x/sys v0.48.0 h1:bbX/i/6MgT9BVLM9RT1thmxL04yeTAhbEz4SyadbXoo=
-golang.org/x/sys v0.32.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
+golang.org/x/sys v0.48.0/go.mod h1:hNLxWAXmnKAxqDtdwIYC4bM9oQPEecfsnNMuSxOs3og=
+golang.org/x/term v0.46.0 h1:3+OXuTbaKDgwk8jTi3aSLHRlmWqHEUDUtxnbFigO4YE=
+golang.org/x/term v0.46.0/go.mod h1:+K02xbkittuwc0Am4abfA3Fc+XRGXkvBXNO88NCXPoc=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

internal/build/build.go

@@ -110,7 +110,10 @@ func generateMain(m Manifest) ([]byte, error) {
 	b.WriteString("\t\t\tcommands = append(commands, hasCommands.Commands()...)\n")
 	b.WriteString("\t\t}\n")
 	b.WriteString("\t}\n")
-	fmt.Fprintf(&b, "\troot := bonfire.NewRoot(%s, commands, out)\n", strconv.Quote(m.Binary))
+	fmt.Fprintf(&b, "\troot, err := bonfire.NewRoot(%s, commands, out)\n", strconv.Quote(m.Binary))
+	b.WriteString("\tif err != nil {\n")
+	b.WriteString("\t\treturn err\n")
+	b.WriteString("\t}\n")
 	b.WriteString("\troot.SetArgs(args)\n")
 	b.WriteString("\treturn root.Execute()\n")
 	b.WriteString("}\n")