src/pkg/flag/flag_test.go

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package flag_test

import (
	"bytes"
	. "flag"
	"fmt"
	"os"
	"sort"
	"strings"
	"testing"
	"time"
)

var (
	test_bool     = Bool("test_bool", false, "bool value")
	test_int      = Int("test_int", 0, "int value")
	test_int64    = Int64("test_int64", 0, "int64 value")
	test_uint     = Uint("test_uint", 0, "uint value")
	test_uint64   = Uint64("test_uint64", 0, "uint64 value")
	test_string   = String("test_string", "0", "string value")
	test_float64  = Float64("test_float64", 0, "float64 value")
	test_duration = Duration("test_duration", 0, "time.Duration value")
)

func boolString(s string) string {
	if s == "0" {
		return "false"
	}
	return "true"
}

func TestEverything(t *testing.T) {
	m := make(map[string]*Flag)
	desired := "0"
	visitor := func(f *Flag) {
		if len(f.Name) > 5 && f.Name[0:5] == "test_" {
			m[f.Name] = f
			ok := false
			switch {
			case f.Value.String() == desired:
				ok = true
			case f.Name == "test_bool" && f.Value.String() == boolString(desired):
				ok = true
			case f.Name == "test_duration" && f.Value.String() == desired+"s":
				ok = true
			}
			if !ok {
				t.Error("Visit: bad value", f.Value.String(), "for", f.Name)
			}
		}
	}
	VisitAll(visitor)
	if len(m) != 8 {
		t.Error("VisitAll misses some flags")
		for k, v := range m {
			t.Log(k, *v)
		}
	}
	m = make(map[string]*Flag)
	Visit(visitor)
	if len(m) != 0 {
		t.Errorf("Visit sees unset flags")
		for k, v := range m {
			t.Log(k, *v)
		}
	}
	// Now set all flags
	Set("test_bool", "true")
	Set("test_int", "1")
	Set("test_int64", "1")
	Set("test_uint", "1")
	Set("test_uint64", "1")
	Set("test_string", "1")
	Set("test_float64", "1")
	Set("test_duration", "1s")
	desired = "1"
	Visit(visitor)
	if len(m) != 8 {
		t.Error("Visit fails after set")
		for k, v := range m {
			t.Log(k, *v)
		}
	}
	// Now test they're visited in sort order.
	var flagNames []string
	Visit(func(f *Flag) { flagNames = append(flagNames, f.Name) })
	if !sort.StringsAreSorted(flagNames) {
		t.Errorf("flag names not sorted: %v", flagNames)
	}
}

func TestUsage(t *testing.T) {
	called := false
	ResetForTesting(func() { called = true })
	if CommandLine().Parse([]string{"-x"}) == nil {
		t.Error("parse did not fail for unknown flag")
	}
	if !called {
		t.Error("did not call Usage for unknown flag")
	}
}

func testParse(f *FlagSet, t *testing.T) {
	if f.Parsed() {
		t.Error("f.Parse() = true before Parse")
	}
	boolFlag := f.Bool("bool", false, "bool value")
	bool2Flag := f.Bool("bool2", false, "bool2 value")
	intFlag := f.Int("int", 0, "int value")
	int64Flag := f.Int64("int64", 0, "int64 value")
	uintFlag := f.Uint("uint", 0, "uint value")
	uint64Flag := f.Uint64("uint64", 0, "uint64 value")
	stringFlag := f.String("string", "0", "string value")
	float64Flag := f.Float64("float64", 0, "float64 value")
	durationFlag := f.Duration("duration", 5*time.Second, "time.Duration value")
	extra := "one-extra-argument"
	args := []string{
		"-bool",
		"-bool2=true",
		"--int", "22",
		"--int64", "0x23",
		"-uint", "24",
		"--uint64", "25",
		"-string", "hello",
		"-float64", "2718e28",
		"-duration", "2m",
		extra,
	}
	if err := f.Parse(args); err != nil {
		t.Fatal(err)
	}
	if !f.Parsed() {
		t.Error("f.Parse() = false after Parse")
	}
	if *boolFlag != true {
		t.Error("bool flag should be true, is ", *boolFlag)
	}
	if *bool2Flag != true {
		t.Error("bool2 flag should be true, is ", *bool2Flag)
	}
	if *intFlag != 22 {
		t.Error("int flag should be 22, is ", *intFlag)
	}
	if *int64Flag != 0x23 {
		t.Error("int64 flag should be 0x23, is ", *int64Flag)
	}
	if *uintFlag != 24 {
		t.Error("uint flag should be 24, is ", *uintFlag)
	}
	if *uint64Flag != 25 {
		t.Error("uint64 flag should be 25, is ", *uint64Flag)
	}
	if *stringFlag != "hello" {
		t.Error("string flag should be `hello`, is ", *stringFlag)
	}
	if *float64Flag != 2718e28 {
		t.Error("float64 flag should be 2718e28, is ", *float64Flag)
	}
	if *durationFlag != 2*time.Minute {
		t.Error("duration flag should be 2m, is ", *durationFlag)
	}
	if len(f.Args()) != 1 {
		t.Error("expected one argument, got", len(f.Args()))
	} else if f.Args()[0] != extra {
		t.Errorf("expected argument %q got %q", extra, f.Args()[0])
	}
}

func TestParse(t *testing.T) {
	ResetForTesting(func() { t.Error("bad parse") })
	testParse(CommandLine(), t)
}

func TestFlagSetParse(t *testing.T) {
	testParse(NewFlagSet("test", ContinueOnError), t)
}

// Declare a user-defined flag type.
type flagVar []string

func (f *flagVar) String() string {
	return fmt.Sprint([]string(*f))
}

func (f *flagVar) Set(value string) error {
	*f = append(*f, value)
	return nil
}

func TestUserDefined(t *testing.T) {
	var flags FlagSet
	flags.Init("test", ContinueOnError)
	var v flagVar
	flags.Var(&v, "v", "usage")
	if err := flags.Parse([]string{"-v", "1", "-v", "2", "-v=3"}); err != nil {
		t.Error(err)
	}
	if len(v) != 3 {
		t.Fatal("expected 3 args; got ", len(v))
	}
	expect := "[1 2 3]"
	if v.String() != expect {
		t.Errorf("expected value %q got %q", expect, v.String())
	}
}

func TestSetOutput(t *testing.T) {
	var flags FlagSet
	var buf bytes.Buffer
	flags.SetOutput(&buf)
	flags.Init("test", ContinueOnError)
	flags.Parse([]string{"-unknown"})
	if out := buf.String(); !strings.Contains(out, "-unknown") {
		t.Logf("expected output mentioning unknown; got %q", out)
	}
}

// This tests that one can reset the flags. This still works but not well, and is
// superseded by FlagSet.
func TestChangingArgs(t *testing.T) {
	ResetForTesting(func() { t.Fatal("bad parse") })
	oldArgs := os.Args
	defer func() { os.Args = oldArgs }()
	os.Args = []string{"cmd", "-before", "subcmd", "-after", "args"}
	before := Bool("before", false, "")
	if err := CommandLine().Parse(os.Args[1:]); err != nil {
		t.Fatal(err)
	}
	cmd := Arg(0)
	os.Args = Args()
	after := Bool("after", false, "")
	Parse()
	args := Args()

	if !*before || cmd != "subcmd" || !*after || len(args) != 1 || args[0] != "args" {
		t.Fatalf("expected true subcmd true [args] got %v %v %v %v", *before, cmd, *after, args)
	}
}

// Test that -help invokes the usage message and returns ErrHelp.
func TestHelp(t *testing.T) {
	var helpCalled = false
	fs := NewFlagSet("help test", ContinueOnError)
	fs.Usage = func() { helpCalled = true }
	var flag bool
	fs.BoolVar(&flag, "flag", false, "regular flag")
	// Regular flag invocation should work
	err := fs.Parse([]string{"-flag=true"})
	if err != nil {
		t.Fatal("expected no error; got ", err)
	}
	if !flag {
		t.Error("flag was not set by -flag")
	}
	if helpCalled {
		t.Error("help called for regular flag")
		helpCalled = false // reset for next test
	}
	// Help flag should work as expected.
	err = fs.Parse([]string{"-help"})
	if err == nil {
		t.Fatal("error expected")
	}
	if err != ErrHelp {
		t.Fatal("expected ErrHelp; got ", err)
	}
	if !helpCalled {
		t.Fatal("help was not called")
	}
	// If we define a help flag, that should override.
	var help bool
	fs.BoolVar(&help, "help", false, "help flag")
	helpCalled = false
	err = fs.Parse([]string{"-help"})
	if err != nil {
		t.Fatal("expected no error for defined -help; got ", err)
	}
	if helpCalled {
		t.Fatal("help was called; should not have been for defined help flag")
	}
}