github.com/urfave/cli v1.22.14: App

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/urfave/cli.App in pkg:golang/github.com/urfave/cli@v1.22.14
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:golang/github.com/urfave/cli@v1.22.14
Demonstrate these symbols/APIs:
  - github.com/urfave/cli.App

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 main

import (
	"fmt"
	"os"

	"github.com/urfave/cli"
)

// NewApp creates a cli.App configured with custom metadata, handlers, and actions.
func NewApp() *cli.App {
	app := cli.NewApp()
	app.Name = "cliapp"
	app.Usage = "demonstrate urfave/cli.App features"
	app.Version = "1.0.0"

	app.Action = func(c *cli.Context) error {
		name := "world"
		if c.Args().Present() {
			name = c.Args().First()
		}
		if c.App.Writer != nil {
			fmt.Fprintf(c.App.Writer, "Hello, %s!\n", name)
		}
		return nil
	}

	app.Commands = []cli.Command{
		{
			Name:  "status",
			Usage: "report application status",
			Action: func(c *cli.Context) error {
				if c.App.Writer != nil {
					fmt.Fprintln(c.App.Writer, "status: operational")
				}
				return nil
			},
		},
	}

	app.CommandNotFound = func(c *cli.Context, command string) {
		if c.App.ErrWriter != nil {
			fmt.Fprintf(c.App.ErrWriter, "command not found: %s\n", command)
		}
	}

	return app
}

func main() {
	app := NewApp()
	if err := app.Run(os.Args); err != nil {
		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
		os.Exit(1)
	}
}

{"case":{"caseId":"case:sha256:e44a1923a94c165ff93580b6ea961453be5f92805a9f891f754109650758d840","contract":["cli.App executes Action with Context and positional arguments","cli.App redirects output to custom Writer and ErrWriter","cli.App propagates error returned by Action","cli.App invokes CommandNotFound handler for unrecognized commands"],"goal":"verify github.com/urfave/cli.App in pkg:golang/github.com/urfave/cli@v1.22.14","kind":"HOW","packages":["pkg:golang/github.com/urfave/cli@v1.22.14"],"schemaVersion":1,"symbols":["github.com/urfave/cli.App"]},"contractCommand":["go","test","./..."],"environment":{"arch":"amd64","distro":"ubuntu","ecosystem":"golang","language":"go","languageVersion":"1.26.6","libc":"glibc","libcVersion":"2.39","moduleSystem":"go-mod","os":"linux","osVersionBucket":"24","packageManager":"go","packageManagerVersion":"1.26.6","runtime":"go","runtimeVersion":"1.26.6","schemaVersion":1},"license":"MIT-0","packages":["pkg:golang/github.com/urfave/cli@v1.22.14"],"schemaVersion":1,"subject":"pkg:golang/github.com/urfave/cli@v1.22.14","symbols":["github.com/urfave/cli.App"],"verifierAdapter":"golang@1"}

module test-urfave-app

go 1.26.6

require (
	github.com/cpuguy83/go-md2man/v2 v2.0.2 // indirect
	github.com/russross/blackfriday/v2 v2.1.0 // indirect
	github.com/urfave/cli v1.22.14
)

github.com/BurntSushi/toml v1.3.2/go.mod h1:CxXYINrC8qIiEnFrOxCa7Jy5BFHlXnUU2pbicEuybxQ=
github.com/cpuguy83/go-md2man/v2 v2.0.2 h1:p1EgwI/C7NhT0JmVkwCD2ZBK8j4aeHQX2pMHHBfMQ6w=
github.com/cpuguy83/go-md2man/v2 v2.0.2/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/russross/blackfriday/v2 v2.1.0 h1:JIOH55/0cWyOuilr9/qlrm0BSXldqnqwMsf35Ld67mk=
github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
github.com/urfave/cli v1.22.14 h1:ebbhrRiGK2i4naQJr+1Xj92HXZCrK7MsyTS/ob3HnAk=
github.com/urfave/cli v1.22.14/go.mod h1:X0eDS6pD6Exaclxm99NJ3FiCDRED7vIHpx2mDOHLvkA=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

{
  "schemaVersion": 1,
  "goal": "verify github.com/urfave/cli.App in pkg:golang/github.com/urfave/cli@v1.22.14",
  "kind": "HOW",
  "packages": [
    "pkg:golang/github.com/urfave/cli@v1.22.14"
  ],
  "symbols": [
    "github.com/urfave/cli.App"
  ]
}

package contract_test

import (
	"bytes"
	"errors"
	"strings"
	"testing"

	"github.com/urfave/cli"
)

func TestContract_AppActionWithContextAndArgs(t *testing.T) {
	app := cli.NewApp()
	app.Name = "cliapp"

	var actionExecuted bool
	var capturedAppName string
	var capturedFirst string
	var capturedSecond string

	app.Action = func(c *cli.Context) error {
		actionExecuted = true
		capturedAppName = c.App.Name
		capturedFirst = c.Args().First()
		capturedSecond = c.Args().Get(1)
		return nil
	}

	err := app.Run([]string{"cliapp", "arg1", "arg2"})
	if err != nil {
		t.Fatalf("unexpected error running app: %v", err)
	}
	if !actionExecuted {
		t.Fatal("expected action to execute")
	}
	if capturedAppName != "cliapp" {
		t.Fatalf("expected app name %q, got %q", "cliapp", capturedAppName)
	}
	if capturedFirst != "arg1" {
		t.Fatalf("expected first arg 'arg1', got %q", capturedFirst)
	}
	if capturedSecond != "arg2" {
		t.Fatalf("expected second arg 'arg2', got %q", capturedSecond)
	}
}

func TestContract_AppCustomWriters(t *testing.T) {
	app := cli.NewApp()
	app.Name = "cliapp"

	var stdoutBuf bytes.Buffer
	var stderrBuf bytes.Buffer
	app.Writer = &stdoutBuf
	app.ErrWriter = &stderrBuf

	app.Action = func(c *cli.Context) error {
		_, _ = c.App.Writer.Write([]byte("standard message\n"))
		_, _ = c.App.ErrWriter.Write([]byte("diagnostic message\n"))
		return nil
	}

	err := app.Run([]string{"cliapp"})
	if err != nil {
		t.Fatalf("unexpected error running app: %v", err)
	}

	if !strings.Contains(stdoutBuf.String(), "standard message") {
		t.Fatalf("expected stdout to contain 'standard message', got %q", stdoutBuf.String())
	}
	if !strings.Contains(stderrBuf.String(), "diagnostic message") {
		t.Fatalf("expected stderr to contain 'diagnostic message', got %q", stderrBuf.String())
	}
}

func TestContract_AppErrorPropagation(t *testing.T) {
	app := cli.NewApp()
	app.Name = "cliapp"

	expectedErr := errors.New("simulated action failure")
	app.Action = func(c *cli.Context) error {
		return expectedErr
	}

	err := app.Run([]string{"cliapp"})
	if err == nil {
		t.Fatal("expected error from app.Run, got nil")
	}
	if err.Error() != expectedErr.Error() {
		t.Fatalf("expected error %q, got %q", expectedErr.Error(), err.Error())
	}
}

func TestContract_AppCommandNotFound(t *testing.T) {
	app := cli.NewApp()
	app.Name = "cliapp"

	var notFoundTriggered bool
	var notFoundCmd string

	app.CommandNotFound = func(c *cli.Context, command string) {
		notFoundTriggered = true
		notFoundCmd = command
	}

	app.Commands = []cli.Command{
		{
			Name: "status",
			Action: func(c *cli.Context) error {
				return nil
			},
		},
	}

	_ = app.Run([]string{"cliapp", "unknown-command"})

	if !notFoundTriggered {
		t.Fatal("expected CommandNotFound handler to be triggered")
	}
	if notFoundCmd != "unknown-command" {
		t.Fatalf("expected command %q, got %q", "unknown-command", notFoundCmd)
	}
}