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-rw-r--r--src/flag/flag_test.go799
1 files changed, 799 insertions, 0 deletions
diff --git a/src/flag/flag_test.go b/src/flag/flag_test.go
new file mode 100644
index 0000000..1755168
--- /dev/null
+++ b/src/flag/flag_test.go
@@ -0,0 +1,799 @@
+// 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"
+ "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 })
+
+ 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
+ }
+ if !ok {
+ t.Error("Visit: bad value", f.Value.String(), "for", f.Name)
+ }
+ }
+ }
+ VisitAll(visitor)
+ if len(m) != 9 {
+ 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")
+ desired = "1"
+ Visit(visitor)
+ if len(m) != 9 {
+ 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 msg != expected {
+ 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)
+ }
+ }
+}