github.com/manifoldco/promptui v0.9.0: Prompt

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify github.com/manifoldco/promptui.Prompt in pkg:golang/github.com/manifoldco/promptui@v0.9.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/manifoldco/promptui@v0.9.0
Demonstrate these symbols/APIs:
  - github.com/manifoldco/promptui.Prompt

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:522bb7d7618db98b7f6bbb28e3ed12137e1a14c25b0a61ca2656413678666d69","contract":["promptui.Prompt runs text input prompt and returns entered string","promptui.Prompt with Default uses default value when empty input is submitted","promptui.Prompt with Validate validates user input using ValidateFunc and rejects invalid values","promptui.Prompt with Mask hides characters for confidential input","promptui.Prompt with IsConfirm handles yes/no confirmation prompts","promptui.Prompt with PromptTemplates renders custom prompt formatting with template colors"],"goal":"verify github.com/manifoldco/promptui.Prompt in pkg:golang/github.com/manifoldco/promptui@v0.9.0","kind":"HOW","packages":["pkg:golang/github.com/manifoldco/promptui@v0.9.0"],"schemaVersion":1,"symbols":["github.com/manifoldco/promptui.Prompt"]},"contractCommand":["go","run","./test"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/manifoldco/promptui@v0.9.0"],"schemaVersion":1,"subject":"pkg:golang/github.com/manifoldco/promptui@v0.9.0","symbols":["github.com/manifoldco/promptui.Prompt"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require github.com/manifoldco/promptui v0.9.0

require (
	github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e // indirect
	golang.org/x/sys v0.0.0-20181122145206-62eef0e2fa9b // indirect
)

github.com/chzyer/logex v1.1.10 h1:Swpa1K6QvQznwJRcfTfQJmTE72DqScAa40E+fbHEXEE=
github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=
github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e h1:fY5BOSpyZCqRo5OhCuC+XN+r/bBCmeuuJtjz+bCNIf8=
github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e/go.mod h1:nSuG5e5PlCu98SY8svDHJxuZscDgtXS6KTTbou5AhLI=
github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1 h1:q763qf9huN11kDQavWsoZXJNW3xEE4JJyHa5Q25/sd8=
github.com/chzyer/test v0.0.0-20180213035817-a1ea475d72b1/go.mod h1:Q3SI9o4m/ZMnBNeIyt5eFwwo7qiLfzFZmjNmxjkiQlU=
github.com/manifoldco/promptui v0.9.0 h1:3V4HzJk1TtXW1MTZMP7mdlwbBpIinw3HztaIlYthEiA=
github.com/manifoldco/promptui v0.9.0/go.mod h1:ka04sppxSGFAtxX0qhlYQjISsg9mR4GWtQEhdbn6Pgg=
golang.org/x/sys v0.0.0-20181122145206-62eef0e2fa9b h1:MQE+LT/ABUuuvEZ+YQAMSXindAdUh7slEmAkup74op4=
golang.org/x/sys v0.0.0-20181122145206-62eef0e2fa9b/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=

package main

import (
	"fmt"

	"github.com/manifoldco/promptui"
)

func main() {
	prompt := promptui.Prompt{
		Label: "Username",
	}
	fmt.Printf("Configured prompt with label %q\n", prompt.Label)
}

{
  "schemaVersion": 1,
  "goal": "verify github.com/manifoldco/promptui.Prompt in pkg:golang/github.com/manifoldco/promptui@v0.9.0",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/manifoldco/promptui@v0.9.0"
  ],
  "symbols": [
    "github.com/manifoldco/promptui.Prompt"
  ]
}

package main

import (
	"bytes"
	"errors"
	"fmt"
	"io"
	"os"
	"strings"

	"github.com/manifoldco/promptui"
)

type nopWriteCloser struct {
	io.Writer
}

func (n nopWriteCloser) Close() error { return nil }

func main() {
	if err := runContract(); err != nil {
		fmt.Fprintf(os.Stderr, "Contract verification failed: %v\n", err)
		os.Exit(1)
	}
	fmt.Println("All promptui.Prompt contract assertions passed successfully.")
}

func runContract() error {
	// 1. promptui.Prompt runs text input prompt and returns entered string
	var out1 bytes.Buffer
	p1 := promptui.Prompt{
		Label:  "Username",
		Stdin:  io.NopCloser(strings.NewReader("octocat\n")),
		Stdout: nopWriteCloser{&out1},
	}
	val1, err := p1.Run()
	if err != nil {
		return fmt.Errorf("p1.Run failed: %w", err)
	}
	if val1 != "octocat" {
		return fmt.Errorf("expected val1 'octocat', got %q", val1)
	}

	// 2. promptui.Prompt with Default uses default value when empty input is submitted
	var out2 bytes.Buffer
	p2 := promptui.Prompt{
		Label:   "Port",
		Default: "8080",
		Stdin:   io.NopCloser(strings.NewReader("\r\n")),
		Stdout:  nopWriteCloser{&out2},
	}
	val2, err := p2.Run()
	if err != nil {
		return fmt.Errorf("p2.Run failed: %w", err)
	}
	if val2 != "8080" {
		return fmt.Errorf("expected default '8080', got %q", val2)
	}

	// 3. promptui.Prompt with Validate validates user input using ValidateFunc and rejects invalid values
	validateEmail := func(s string) error {
		if !strings.Contains(s, "@") {
			return errors.New("missing @ symbol")
		}
		return nil
	}
	if err := validateEmail("invalid-email"); err == nil {
		return fmt.Errorf("expected validation failure for invalid email")
	}
	if err := validateEmail("dev@example.com"); err != nil {
		return fmt.Errorf("expected validation success for valid email, got: %w", err)
	}

	var out3 bytes.Buffer
	p3 := promptui.Prompt{
		Label:    "Email",
		Validate: validateEmail,
		Stdin:    io.NopCloser(strings.NewReader("dev@example.com\n")),
		Stdout:   nopWriteCloser{&out3},
	}
	val3, err := p3.Run()
	if err != nil {
		return fmt.Errorf("p3.Run failed: %w", err)
	}
	if val3 != "dev@example.com" {
		return fmt.Errorf("expected email 'dev@example.com', got %q", val3)
	}

	// 4. promptui.Prompt with Mask hides characters for confidential input
	var out4 bytes.Buffer
	p4 := promptui.Prompt{
		Label:  "Password",
		Mask:   '*',
		Stdin:  io.NopCloser(strings.NewReader("secret123\n")),
		Stdout: nopWriteCloser{&out4},
	}
	val4, err := p4.Run()
	if err != nil {
		return fmt.Errorf("p4.Run failed: %w", err)
	}
	if val4 != "secret123" {
		return fmt.Errorf("expected mask prompt value 'secret123', got %q", val4)
	}

	// 5. promptui.Prompt with IsConfirm handles yes/no confirmation prompts
	var out5 bytes.Buffer
	p5 := promptui.Prompt{
		Label:     "Continue",
		IsConfirm: true,
		Stdin:     io.NopCloser(strings.NewReader("y\n")),
		Stdout:    nopWriteCloser{&out5},
	}
	val5, err := p5.Run()
	if err != nil {
		return fmt.Errorf("p5.Run failed: %w", err)
	}
	if val5 != "y" && val5 != "Y" {
		return fmt.Errorf("expected confirmation 'y' or 'Y', got %q", val5)
	}

	// 6. promptui.Prompt with PromptTemplates renders custom prompt formatting with template colors
	var out6 bytes.Buffer
	p6 := promptui.Prompt{
		Label: "Custom Prompt",
		Templates: &promptui.PromptTemplates{
			Prompt:  "{{ . | bold }} ",
			Valid:   "{{ . | green }} ",
			Invalid: "{{ . | red }} ",
			Success: "{{ . | bold | green }} ",
		},
		Stdin:  io.NopCloser(strings.NewReader("custom-value\n")),
		Stdout: nopWriteCloser{&out6},
	}
	val6, err := p6.Run()
	if err != nil {
		return fmt.Errorf("p6.Run failed: %w", err)
	}
	if val6 != "custom-value" {
		return fmt.Errorf("expected custom prompt value 'custom-value', got %q", val6)
	}

	return nil
}