golang.org/x/term v0.0.0-20210927222741-03fcf44c2211: IsTerminal, NewTerminal, Terminal.ReadLine

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 pkg:golang/golang.org/x/term@v0.0.0-20210927222741-03fcf44c2211
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/golang.org/x/term@v0.0.0-20210927222741-03fcf44c2211
Demonstrate these symbols/APIs:
  - golang.org/x/term.IsTerminal
  - golang.org/x/term.NewTerminal
  - golang.org/x/term.Terminal.ReadLine
  - golang.org/x/term.Terminal.ReadPassword
  - golang.org/x/term.Terminal.SetPrompt
  - golang.org/x/term.Terminal.SetSize
  - golang.org/x/term.Terminal.Write

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.

package sample_test

import (
	"bytes"
	"os"
	"strings"
	"testing"

	"golang.org/x/term"
)

type bufferRW struct {
	in  *bytes.Buffer
	out *bytes.Buffer
}

func (rw *bufferRW) Read(p []byte) (n int, err error) {
	return rw.in.Read(p)
}

func (rw *bufferRW) Write(p []byte) (n int, err error) {
	return rw.out.Write(p)
}

func newBufferRW(input string) *bufferRW {
	return &bufferRW{
		in:  bytes.NewBufferString(input),
		out: &bytes.Buffer{},
	}
}

func TestIsTerminal(t *testing.T) {
	// 1. Invalid file descriptor returns false
	if term.IsTerminal(-1) {
		t.Fatal("expected IsTerminal(-1) to be false")
	}

	// 2. Non-terminal pipe file descriptor returns false
	r, w, err := os.Pipe()
	if err != nil {
		t.Fatalf("failed to create pipe: %v", err)
	}
	defer r.Close()
	defer w.Close()

	if term.IsTerminal(int(r.Fd())) {
		t.Fatal("expected pipe reader to not be a terminal")
	}
	if term.IsTerminal(int(w.Fd())) {
		t.Fatal("expected pipe writer to not be a terminal")
	}
}

func TestTerminalReadLine(t *testing.T) {
	rw := newBufferRW("hello world\r\n")
	terminal := term.NewTerminal(rw, "> ")

	line, err := terminal.ReadLine()
	if err != nil {
		t.Fatalf("ReadLine failed: %v", err)
	}
	if line != "hello world" {
		t.Fatalf("expected 'hello world', got '%s'", line)
	}

	if !strings.Contains(rw.out.String(), "> ") {
		t.Fatalf("expected prompt '> ' in output, got '%s'", rw.out.String())
	}
}

func TestTerminalSetPrompt(t *testing.T) {
	rw := newBufferRW("cmd1\r\ncmd2\r\n")
	terminal := term.NewTerminal(rw, "first> ")

	line1, err := terminal.ReadLine()
	if err != nil || line1 != "cmd1" {
		t.Fatalf("first ReadLine failed: line=%s, err=%v", line1, err)
	}

	terminal.SetPrompt("second> ")
	line2, err := terminal.ReadLine()
	if err != nil || line2 != "cmd2" {
		t.Fatalf("second ReadLine failed: line=%s, err=%v", line2, err)
	}

	outStr := rw.out.String()
	if !strings.Contains(outStr, "first> ") || !strings.Contains(outStr, "second> ") {
		t.Fatalf("expected output to contain both prompts, got '%s'", outStr)
	}
}

func TestTerminalReadPassword(t *testing.T) {
	rw := newBufferRW("mysecretpassword\r\n")
	terminal := term.NewTerminal(rw, "")

	pass, err := terminal.ReadPassword("Password: ")
	if err != nil {
		t.Fatalf("ReadPassword failed: %v", err)
	}
	if pass != "mysecretpassword" {
		t.Fatalf("expected 'mysecretpassword', got '%s'", pass)
	}

	outStr := rw.out.String()
	if !strings.Contains(outStr, "Password: ") {
		t.Fatalf("expected prompt in output, got '%s'", outStr)
	}
	if strings.Contains(outStr, "mysecretpassword") {
		t.Fatalf("password should not be echoed in output, got '%s'", outStr)
	}
}

func TestTerminalSetSize(t *testing.T) {
	rw := newBufferRW("")
	terminal := term.NewTerminal(rw, "")

	if err := terminal.SetSize(80, 24); err != nil {
		t.Fatalf("SetSize(80, 24) failed: %v", err)
	}
	if err := terminal.SetSize(120, 40); err != nil {
		t.Fatalf("SetSize(120, 40) failed: %v", err)
	}
}

func TestTerminalWrite(t *testing.T) {
	rw := newBufferRW("")
	terminal := term.NewTerminal(rw, "")

	n, err := terminal.Write([]byte("line1\nline2\n"))
	if err != nil {
		t.Fatalf("terminal.Write failed: %v", err)
	}
	if n != 12 {
		t.Fatalf("expected 12 bytes written, got %d", n)
	}

	expected := "line1\r\nline2\r\n"
	if rw.out.String() != expected {
		t.Fatalf("expected output %q, got %q", expected, rw.out.String())
	}
}

{"case":{"caseId":"case:sha256:dc804ea7511945bf74af91134d90833c0af4ff2fb07b3f6c7098ebea343e2bf2","contract":["term.IsTerminal reports whether the given file descriptor is a terminal","term.NewTerminal initializes a VT100 terminal handler over an io.ReadWriter with a prompt","term.Terminal.ReadLine reads a line of input terminated by newline and strips trailing newline","term.Terminal.SetPrompt updates the prompt string displayed before reading input","term.Terminal.ReadPassword reads password input without echoing characters to output","term.Terminal.SetSize configures the terminal dimensions","term.Terminal.Write writes formatted output translating newline characters"],"goal":"verify pkg:golang/golang.org/x/term@v0.0.0-20210927222741-03fcf44c2211","kind":"HOW","packages":["pkg:golang/golang.org/x/term@v0.0.0-20210927222741-03fcf44c2211"],"schemaVersion":1,"symbols":["golang.org/x/term.IsTerminal","golang.org/x/term.NewTerminal","golang.org/x/term.Terminal.ReadLine","golang.org/x/term.Terminal.ReadPassword","golang.org/x/term.Terminal.SetPrompt","golang.org/x/term.Terminal.SetSize","golang.org/x/term.Terminal.Write"]},"contractCommand":["go","test","-v","./..."],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"golang","language":"go","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"go","packageManagerVersion":"1.26.6","runtime":"go","runtimeVersion":"1.26.6","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/golang.org/x/term@v0.0.0-20210927222741-03fcf44c2211"],"schemaVersion":1,"subject":"pkg:golang/golang.org/x/term@v0.0.0-20210927222741-03fcf44c2211","symbols":["golang.org/x/term.IsTerminal","golang.org/x/term.NewTerminal","golang.org/x/term.Terminal.ReadLine","golang.org/x/term.Terminal.ReadPassword","golang.org/x/term.Terminal.SetPrompt","golang.org/x/term.Terminal.SetSize","golang.org/x/term.Terminal.Write"],"verifierAdapter":"golang@1"}

module sample

go 1.26.6

require golang.org/x/term v0.0.0-20210927222741-03fcf44c2211

require golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1 // indirect

golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1 h1:SrN+KX8Art/Sf4HNj6Zcz06G7VEz+7w9tdXTPOZ7+l4=
golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
golang.org/x/term v0.0.0-20210927222741-03fcf44c2211 h1:JGgROgKl9N8DuW20oFS5gxc+lE67/N3FcwmBPMe7ArY=
golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=

{
  "schemaVersion": 1,
  "goal": "verify pkg:golang/golang.org/x/term@v0.0.0-20210927222741-03fcf44c2211",
  "kind": "HOW",
  "packages": [
    "pkg:golang/golang.org/x/term@v0.0.0-20210927222741-03fcf44c2211"
  ],
  "symbols": [
    "golang.org/x/term.IsTerminal",
    "golang.org/x/term.NewTerminal",
    "golang.org/x/term.Terminal.ReadLine",
    "golang.org/x/term.Terminal.ReadPassword",
    "golang.org/x/term.Terminal.SetPrompt",
    "golang.org/x/term.Terminal.SetSize",
    "golang.org/x/term.Terminal.Write"
  ]
}