diff options
Diffstat (limited to 'src/flag/flag_test.go')
-rw-r--r-- | src/flag/flag_test.go | 858 |
1 files changed, 858 insertions, 0 deletions
diff --git a/src/flag/flag_test.go b/src/flag/flag_test.go new file mode 100644 index 0000000..8e9ae31 --- /dev/null +++ b/src/flag/flag_test.go @@ -0,0 +1,858 @@ +// 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" + "internal/testenv" + "io" + "os" + "os/exec" + "regexp" + "runtime" + "sort" + "strconv" + "strings" + "testing" + "time" +) + +func boolString(s string) string { + if s == "0" { + return "false" + } + return "true" +} + +func TestEverything(t *testing.T) { + ResetForTesting(nil) + Bool("test_bool", false, "bool value") + Int("test_int", 0, "int value") + Int64("test_int64", 0, "int64 value") + Uint("test_uint", 0, "uint value") + Uint64("test_uint64", 0, "uint64 value") + String("test_string", "0", "string value") + Float64("test_float64", 0, "float64 value") + Duration("test_duration", 0, "time.Duration value") + Func("test_func", "func value", func(string) error { return nil }) + BoolFunc("test_boolfunc", "func", func(string) error { return nil }) + + 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 + case f.Name == "test_func" && f.Value.String() == "": + ok = true + case f.Name == "test_boolfunc" && f.Value.String() == "": + ok = true + } + if !ok { + t.Error("Visit: bad value", f.Value.String(), "for", f.Name) + } + } + } + VisitAll(visitor) + if len(m) != 10 { + 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") + Set("test_func", "1") + Set("test_boolfunc", "") + desired = "1" + Visit(visitor) + if len(m) != 10 { + 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 TestGet(t *testing.T) { + ResetForTesting(nil) + Bool("test_bool", true, "bool value") + Int("test_int", 1, "int value") + Int64("test_int64", 2, "int64 value") + Uint("test_uint", 3, "uint value") + Uint64("test_uint64", 4, "uint64 value") + String("test_string", "5", "string value") + Float64("test_float64", 6, "float64 value") + Duration("test_duration", 7, "time.Duration value") + + visitor := func(f *Flag) { + if len(f.Name) > 5 && f.Name[0:5] == "test_" { + g, ok := f.Value.(Getter) + if !ok { + t.Errorf("Visit: value does not satisfy Getter: %T", f.Value) + return + } + switch f.Name { + case "test_bool": + ok = g.Get() == true + case "test_int": + ok = g.Get() == int(1) + case "test_int64": + ok = g.Get() == int64(2) + case "test_uint": + ok = g.Get() == uint(3) + case "test_uint64": + ok = g.Get() == uint64(4) + case "test_string": + ok = g.Get() == "5" + case "test_float64": + ok = g.Get() == float64(6) + case "test_duration": + ok = g.Get() == time.Duration(7) + } + if !ok { + t.Errorf("Visit: bad value %T(%v) for %s", g.Get(), g.Get(), f.Name) + } + } + } + VisitAll(visitor) +} + +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) + flags.SetOutput(io.Discard) + 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 TestUserDefinedFunc(t *testing.T) { + flags := NewFlagSet("test", ContinueOnError) + flags.SetOutput(io.Discard) + var ss []string + flags.Func("v", "usage", func(s string) error { + ss = append(ss, s) + return nil + }) + if err := flags.Parse([]string{"-v", "1", "-v", "2", "-v=3"}); err != nil { + t.Error(err) + } + if len(ss) != 3 { + t.Fatal("expected 3 args; got ", len(ss)) + } + expect := "[1 2 3]" + if got := fmt.Sprint(ss); got != expect { + t.Errorf("expected value %q got %q", expect, got) + } + // test usage + var buf strings.Builder + flags.SetOutput(&buf) + flags.Parse([]string{"-h"}) + if usage := buf.String(); !strings.Contains(usage, "usage") { + t.Errorf("usage string not included: %q", usage) + } + // test Func error + flags = NewFlagSet("test", ContinueOnError) + flags.SetOutput(io.Discard) + flags.Func("v", "usage", func(s string) error { + return fmt.Errorf("test error") + }) + // flag not set, so no error + if err := flags.Parse(nil); err != nil { + t.Error(err) + } + // flag set, expect error + if err := flags.Parse([]string{"-v", "1"}); err == nil { + t.Error("expected error; got none") + } else if errMsg := err.Error(); !strings.Contains(errMsg, "test error") { + t.Errorf(`error should contain "test error"; got %q`, errMsg) + } +} + +func TestUserDefinedForCommandLine(t *testing.T) { + const help = "HELP" + var result string + ResetForTesting(func() { result = help }) + Usage() + if result != help { + t.Fatalf("got %q; expected %q", result, help) + } +} + +// Declare a user-defined boolean flag type. +type boolFlagVar struct { + count int +} + +func (b *boolFlagVar) String() string { + return fmt.Sprintf("%d", b.count) +} + +func (b *boolFlagVar) Set(value string) error { + if value == "true" { + b.count++ + } + return nil +} + +func (b *boolFlagVar) IsBoolFlag() bool { + return b.count < 4 +} + +func TestUserDefinedBool(t *testing.T) { + var flags FlagSet + flags.Init("test", ContinueOnError) + flags.SetOutput(io.Discard) + var b boolFlagVar + var err error + flags.Var(&b, "b", "usage") + if err = flags.Parse([]string{"-b", "-b", "-b", "-b=true", "-b=false", "-b", "barg", "-b"}); err != nil { + if b.count < 4 { + t.Error(err) + } + } + + if b.count != 4 { + t.Errorf("want: %d; got: %d", 4, b.count) + } + + if err == nil { + t.Error("expected error; got none") + } +} + +func TestUserDefinedBoolUsage(t *testing.T) { + var flags FlagSet + flags.Init("test", ContinueOnError) + var buf bytes.Buffer + flags.SetOutput(&buf) + var b boolFlagVar + flags.Var(&b, "b", "X") + b.count = 0 + // b.IsBoolFlag() will return true and usage will look boolean. + flags.PrintDefaults() + got := buf.String() + want := " -b\tX\n" + if got != want { + t.Errorf("false: want %q; got %q", want, got) + } + b.count = 4 + // b.IsBoolFlag() will return false and usage will look non-boolean. + flags.PrintDefaults() + got = buf.String() + want = " -b\tX\n -b value\n \tX\n" + if got != want { + t.Errorf("false: want %q; got %q", want, got) + } +} + +func TestSetOutput(t *testing.T) { + var flags FlagSet + var buf strings.Builder + 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") + } +} + +// zeroPanicker is a flag.Value whose String method panics if its dontPanic +// field is false. +type zeroPanicker struct { + dontPanic bool + v string +} + +func (f *zeroPanicker) Set(s string) error { + f.v = s + return nil +} + +func (f *zeroPanicker) String() string { + if !f.dontPanic { + panic("panic!") + } + return f.v +} + +const defaultOutput = ` -A for bootstrapping, allow 'any' type + -Alongflagname + disable bounds checking + -C a boolean defaulting to true (default true) + -D path + set relative path for local imports + -E string + issue 23543 (default "0") + -F number + a non-zero number (default 2.7) + -G float + a float that defaults to zero + -M string + a multiline + help + string + -N int + a non-zero int (default 27) + -O a flag + multiline help string (default true) + -V list + a list of strings (default [a b]) + -Z int + an int that defaults to zero + -ZP0 value + a flag whose String method panics when it is zero + -ZP1 value + a flag whose String method panics when it is zero + -maxT timeout + set timeout for dial + +panic calling String method on zero flag_test.zeroPanicker for flag ZP0: panic! +panic calling String method on zero flag_test.zeroPanicker for flag ZP1: panic! +` + +func TestPrintDefaults(t *testing.T) { + fs := NewFlagSet("print defaults test", ContinueOnError) + var buf strings.Builder + fs.SetOutput(&buf) + fs.Bool("A", false, "for bootstrapping, allow 'any' type") + fs.Bool("Alongflagname", false, "disable bounds checking") + fs.Bool("C", true, "a boolean defaulting to true") + fs.String("D", "", "set relative `path` for local imports") + fs.String("E", "0", "issue 23543") + fs.Float64("F", 2.7, "a non-zero `number`") + fs.Float64("G", 0, "a float that defaults to zero") + fs.String("M", "", "a multiline\nhelp\nstring") + fs.Int("N", 27, "a non-zero int") + fs.Bool("O", true, "a flag\nmultiline help string") + fs.Var(&flagVar{"a", "b"}, "V", "a `list` of strings") + fs.Int("Z", 0, "an int that defaults to zero") + fs.Var(&zeroPanicker{true, ""}, "ZP0", "a flag whose String method panics when it is zero") + fs.Var(&zeroPanicker{true, "something"}, "ZP1", "a flag whose String method panics when it is zero") + fs.Duration("maxT", 0, "set `timeout` for dial") + fs.PrintDefaults() + got := buf.String() + if got != defaultOutput { + t.Errorf("got:\n%q\nwant:\n%q", got, defaultOutput) + } +} + +// Issue 19230: validate range of Int and Uint flag values. +func TestIntFlagOverflow(t *testing.T) { + if strconv.IntSize != 32 { + return + } + ResetForTesting(nil) + Int("i", 0, "") + Uint("u", 0, "") + if err := Set("i", "2147483648"); err == nil { + t.Error("unexpected success setting Int") + } + if err := Set("u", "4294967296"); err == nil { + t.Error("unexpected success setting Uint") + } +} + +// Issue 20998: Usage should respect CommandLine.output. +func TestUsageOutput(t *testing.T) { + ResetForTesting(DefaultUsage) + var buf strings.Builder + CommandLine.SetOutput(&buf) + defer func(old []string) { os.Args = old }(os.Args) + os.Args = []string{"app", "-i=1", "-unknown"} + Parse() + const want = "flag provided but not defined: -i\nUsage of app:\n" + if got := buf.String(); got != want { + t.Errorf("output = %q; want %q", got, want) + } +} + +func TestGetters(t *testing.T) { + expectedName := "flag set" + expectedErrorHandling := ContinueOnError + expectedOutput := io.Writer(os.Stderr) + fs := NewFlagSet(expectedName, expectedErrorHandling) + + if fs.Name() != expectedName { + t.Errorf("unexpected name: got %s, expected %s", fs.Name(), expectedName) + } + if fs.ErrorHandling() != expectedErrorHandling { + t.Errorf("unexpected ErrorHandling: got %d, expected %d", fs.ErrorHandling(), expectedErrorHandling) + } + if fs.Output() != expectedOutput { + t.Errorf("unexpected output: got %#v, expected %#v", fs.Output(), expectedOutput) + } + + expectedName = "gopher" + expectedErrorHandling = ExitOnError + expectedOutput = os.Stdout + fs.Init(expectedName, expectedErrorHandling) + fs.SetOutput(expectedOutput) + + if fs.Name() != expectedName { + t.Errorf("unexpected name: got %s, expected %s", fs.Name(), expectedName) + } + if fs.ErrorHandling() != expectedErrorHandling { + t.Errorf("unexpected ErrorHandling: got %d, expected %d", fs.ErrorHandling(), expectedErrorHandling) + } + if fs.Output() != expectedOutput { + t.Errorf("unexpected output: got %v, expected %v", fs.Output(), expectedOutput) + } +} + +func TestParseError(t *testing.T) { + for _, typ := range []string{"bool", "int", "int64", "uint", "uint64", "float64", "duration"} { + fs := NewFlagSet("parse error test", ContinueOnError) + fs.SetOutput(io.Discard) + _ = fs.Bool("bool", false, "") + _ = fs.Int("int", 0, "") + _ = fs.Int64("int64", 0, "") + _ = fs.Uint("uint", 0, "") + _ = fs.Uint64("uint64", 0, "") + _ = fs.Float64("float64", 0, "") + _ = fs.Duration("duration", 0, "") + // Strings cannot give errors. + args := []string{"-" + typ + "=x"} + err := fs.Parse(args) // x is not a valid setting for any flag. + if err == nil { + t.Errorf("Parse(%q)=%v; expected parse error", args, err) + continue + } + if !strings.Contains(err.Error(), "invalid") || !strings.Contains(err.Error(), "parse error") { + t.Errorf("Parse(%q)=%v; expected parse error", args, err) + } + } +} + +func TestRangeError(t *testing.T) { + bad := []string{ + "-int=123456789012345678901", + "-int64=123456789012345678901", + "-uint=123456789012345678901", + "-uint64=123456789012345678901", + "-float64=1e1000", + } + for _, arg := range bad { + fs := NewFlagSet("parse error test", ContinueOnError) + fs.SetOutput(io.Discard) + _ = fs.Int("int", 0, "") + _ = fs.Int64("int64", 0, "") + _ = fs.Uint("uint", 0, "") + _ = fs.Uint64("uint64", 0, "") + _ = fs.Float64("float64", 0, "") + // Strings cannot give errors, and bools and durations do not return strconv.NumError. + err := fs.Parse([]string{arg}) + if err == nil { + t.Errorf("Parse(%q)=%v; expected range error", arg, err) + continue + } + if !strings.Contains(err.Error(), "invalid") || !strings.Contains(err.Error(), "value out of range") { + t.Errorf("Parse(%q)=%v; expected range error", arg, err) + } + } +} + +func TestExitCode(t *testing.T) { + testenv.MustHaveExec(t) + + magic := 123 + if os.Getenv("GO_CHILD_FLAG") != "" { + fs := NewFlagSet("test", ExitOnError) + if os.Getenv("GO_CHILD_FLAG_HANDLE") != "" { + var b bool + fs.BoolVar(&b, os.Getenv("GO_CHILD_FLAG_HANDLE"), false, "") + } + fs.Parse([]string{os.Getenv("GO_CHILD_FLAG")}) + os.Exit(magic) + } + + tests := []struct { + flag string + flagHandle string + expectExit int + }{ + { + flag: "-h", + expectExit: 0, + }, + { + flag: "-help", + expectExit: 0, + }, + { + flag: "-undefined", + expectExit: 2, + }, + { + flag: "-h", + flagHandle: "h", + expectExit: magic, + }, + { + flag: "-help", + flagHandle: "help", + expectExit: magic, + }, + } + + for _, test := range tests { + cmd := exec.Command(os.Args[0], "-test.run=^TestExitCode$") + cmd.Env = append( + os.Environ(), + "GO_CHILD_FLAG="+test.flag, + "GO_CHILD_FLAG_HANDLE="+test.flagHandle, + ) + cmd.Run() + got := cmd.ProcessState.ExitCode() + // ExitCode is either 0 or 1 on Plan 9. + if runtime.GOOS == "plan9" && test.expectExit != 0 { + test.expectExit = 1 + } + if got != test.expectExit { + t.Errorf("unexpected exit code for test case %+v \n: got %d, expect %d", + test, got, test.expectExit) + } + } +} + +func mustPanic(t *testing.T, testName string, expected string, f func()) { + t.Helper() + defer func() { + switch msg := recover().(type) { + case nil: + t.Errorf("%s\n: expected panic(%q), but did not panic", testName, expected) + case string: + if ok, _ := regexp.MatchString(expected, msg); !ok { + t.Errorf("%s\n: expected panic(%q), but got panic(%q)", testName, expected, msg) + } + default: + t.Errorf("%s\n: expected panic(%q), but got panic(%T%v)", testName, expected, msg, msg) + } + }() + f() +} + +func TestInvalidFlags(t *testing.T) { + tests := []struct { + flag string + errorMsg string + }{ + { + flag: "-foo", + errorMsg: "flag \"-foo\" begins with -", + }, + { + flag: "foo=bar", + errorMsg: "flag \"foo=bar\" contains =", + }, + } + + for _, test := range tests { + testName := fmt.Sprintf("FlagSet.Var(&v, %q, \"\")", test.flag) + + fs := NewFlagSet("", ContinueOnError) + buf := &strings.Builder{} + fs.SetOutput(buf) + + mustPanic(t, testName, test.errorMsg, func() { + var v flagVar + fs.Var(&v, test.flag, "") + }) + if msg := test.errorMsg + "\n"; msg != buf.String() { + t.Errorf("%s\n: unexpected output: expected %q, bug got %q", testName, msg, buf) + } + } +} + +func TestRedefinedFlags(t *testing.T) { + tests := []struct { + flagSetName string + errorMsg string + }{ + { + flagSetName: "", + errorMsg: "flag redefined: foo", + }, + { + flagSetName: "fs", + errorMsg: "fs flag redefined: foo", + }, + } + + for _, test := range tests { + testName := fmt.Sprintf("flag redefined in FlagSet(%q)", test.flagSetName) + + fs := NewFlagSet(test.flagSetName, ContinueOnError) + buf := &strings.Builder{} + fs.SetOutput(buf) + + var v flagVar + fs.Var(&v, "foo", "") + + mustPanic(t, testName, test.errorMsg, func() { + fs.Var(&v, "foo", "") + }) + if msg := test.errorMsg + "\n"; msg != buf.String() { + t.Errorf("%s\n: unexpected output: expected %q, bug got %q", testName, msg, buf) + } + } +} + +func TestUserDefinedBoolFunc(t *testing.T) { + flags := NewFlagSet("test", ContinueOnError) + flags.SetOutput(io.Discard) + var ss []string + flags.BoolFunc("v", "usage", func(s string) error { + ss = append(ss, s) + return nil + }) + if err := flags.Parse([]string{"-v", "", "-v", "1", "-v=2"}); err != nil { + t.Error(err) + } + if len(ss) != 1 { + t.Fatalf("got %d args; want 1 arg", len(ss)) + } + want := "[true]" + if got := fmt.Sprint(ss); got != want { + t.Errorf("got %q; want %q", got, want) + } + // test usage + var buf strings.Builder + flags.SetOutput(&buf) + flags.Parse([]string{"-h"}) + if usage := buf.String(); !strings.Contains(usage, "usage") { + t.Errorf("usage string not included: %q", usage) + } + // test BoolFunc error + flags = NewFlagSet("test", ContinueOnError) + flags.SetOutput(io.Discard) + flags.BoolFunc("v", "usage", func(s string) error { + return fmt.Errorf("test error") + }) + // flag not set, so no error + if err := flags.Parse(nil); err != nil { + t.Error(err) + } + // flag set, expect error + if err := flags.Parse([]string{"-v", ""}); err == nil { + t.Error("got err == nil; want err != nil") + } else if errMsg := err.Error(); !strings.Contains(errMsg, "test error") { + t.Errorf(`got %q; error should contain "test error"`, errMsg) + } +} + +func TestDefineAfterSet(t *testing.T) { + flags := NewFlagSet("test", ContinueOnError) + // Set by itself doesn't panic. + flags.Set("myFlag", "value") + + // Define-after-set panics. + mustPanic(t, "DefineAfterSet", "flag myFlag set at .*/flag_test.go:.* before being defined", func() { + _ = flags.String("myFlag", "default", "usage") + }) +} |