Subversion Repositories openrisc

// 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 fmt_test

import (
        "bytes"
        . "fmt"
        "io"
        "math"
        "runtime" // for the malloc count test only
        "strings"
        "testing"
        "time"
)

type (
        renamedBool       bool
        renamedInt        int
        renamedInt8       int8
        renamedInt16      int16
        renamedInt32      int32
        renamedInt64      int64
        renamedUint       uint
        renamedUint8      uint8
        renamedUint16     uint16
        renamedUint32     uint32
        renamedUint64     uint64
        renamedUintptr    uintptr
        renamedString     string
        renamedBytes      []byte
        renamedFloat32    float32
        renamedFloat64    float64
        renamedComplex64  complex64
        renamedComplex128 complex128
)

func TestFmtInterface(t *testing.T) {
        var i1 interface{}
        i1 = "abc"
        s := Sprintf("%s", i1)
        if s != "abc" {
                t.Errorf(`Sprintf("%%s", empty("abc")) = %q want %q`, s, "abc")
        }
}

const b32 uint32 = 1<<32 - 1
const b64 uint64 = 1<<64 - 1

var array = [5]int{1, 2, 3, 4, 5}
var iarray = [4]interface{}{1, "hello", 2.5, nil}
var slice = array[:]
var islice = iarray[:]

type A struct {
        i int
        j uint
        s string
        x []int
}

type I int

func (i I) String() string { return Sprintf("<%d>", int(i)) }

type B struct {
        I I
        j int
}

type C struct {
        i int
        B
}

type F int

func (f F) Format(s State, c rune) {
        Fprintf(s, "<%c=F(%d)>", c, int(f))
}

type G int

func (g G) GoString() string {
        return Sprintf("GoString(%d)", int(g))
}

type S struct {
        F F // a struct field that Formats
        G G // a struct field that GoStrings
}

type SI struct {
        I interface{}
}

// A type with a String method with pointer receiver for testing %p
type P int

var pValue P

func (p *P) String() string {
        return "String(p)"
}

var b byte

var fmttests = []struct {
        fmt string
        val interface{}
        out string
}{
        {"%d", 12345, "12345"},
        {"%v", 12345, "12345"},
        {"%t", true, "true"},

        // basic string
        {"%s", "abc", "abc"},
        {"%x", "abc", "616263"},
        {"%x", "xyz", "78797a"},
        {"%X", "xyz", "78797A"},
        {"%q", "abc", `"abc"`},

        // basic bytes
        {"%s", []byte("abc"), "abc"},
        {"%x", []byte("abc"), "616263"},
        {"% x", []byte("abc\xff"), "61 62 63 ff"},
        {"% X", []byte("abc\xff"), "61 62 63 FF"},
        {"%x", []byte("xyz"), "78797a"},
        {"%X", []byte("xyz"), "78797A"},
        {"%q", []byte("abc"), `"abc"`},

        // escaped strings
        {"%#q", `abc`, "`abc`"},
        {"%#q", `"`, "`\"`"},
        {"1 %#q", `\n`, "1 `\\n`"},
        {"2 %#q", "\n", `2 "\n"`},
        {"%q", `"`, `"\""`},
        {"%q", "\a\b\f\r\n\t\v", `"\a\b\f\r\n\t\v"`},
        {"%q", "abc\xffdef", `"abc\xffdef"`},
        {"%q", "\u263a", `"☺"`},
        {"%+q", "\u263a", `"\u263a"`},
        {"%q", "\U0010ffff", `"\U0010ffff"`},

        // escaped characters
        {"%q", 'x', `'x'`},
        {"%q", 0, `'\x00'`},
        {"%q", '\n', `'\n'`},
        {"%q", '\u0e00', `'\u0e00'`},         // not a printable rune.
        {"%q", '\U000c2345', `'\U000c2345'`}, // not a printable rune.
        {"%q", int64(0x7FFFFFFF), `%!q(int64=2147483647)`},
        {"%q", uint64(0xFFFFFFFF), `%!q(uint64=4294967295)`},
        {"%q", '"', `'"'`},
        {"%q", '\'', `'\''`},
        {"%q", "\u263a", `"☺"`},
        {"%+q", "\u263a", `"\u263a"`},

        // width
        {"%5s", "abc", "  abc"},
        {"%2s", "\u263a", " ☺"},
        {"%-5s", "abc", "abc  "},
        {"%-8q", "abc", `"abc"   `},
        {"%05s", "abc", "00abc"},
        {"%08q", "abc", `000"abc"`},
        {"%5s", "abcdefghijklmnopqrstuvwxyz", "abcdefghijklmnopqrstuvwxyz"},
        {"%.5s", "abcdefghijklmnopqrstuvwxyz", "abcde"},
        {"%.5s", "日本語日本語", "日本語日本"},
        {"%.5s", []byte("日本語日本語"), "日本語日本"},
        {"%.5q", "abcdefghijklmnopqrstuvwxyz", `"abcde"`},
        {"%.3q", "日本語日本語", `"日本語"`},
        {"%.3q", []byte("日本語日本語"), `"日本語"`},
        {"%10.1q", "日本語日本語", `       "日"`},

        // integers
        {"%d", 12345, "12345"},
        {"%d", -12345, "-12345"},
        {"%10d", 12345, "     12345"},
        {"%10d", -12345, "    -12345"},
        {"%+10d", 12345, "    +12345"},
        {"%010d", 12345, "0000012345"},
        {"%010d", -12345, "-000012345"},
        {"%-10d", 12345, "12345     "},
        {"%010.3d", 1, "       001"},
        {"%010.3d", -1, "      -001"},
        {"%+d", 12345, "+12345"},
        {"%+d", -12345, "-12345"},
        {"%+d", 0, "+0"},
        {"% d", 0, " 0"},
        {"% d", 12345, " 12345"},
        {"%.0d", 0, ""},
        {"%.d", 0, ""},

        // unicode format
        {"%U", 0x1, "U+0001"},
        {"%U", uint(0x1), "U+0001"},
        {"%.8U", 0x2, "U+00000002"},
        {"%U", 0x1234, "U+1234"},
        {"%U", 0x12345, "U+12345"},
        {"%10.6U", 0xABC, "  U+000ABC"},
        {"%-10.6U", 0xABC, "U+000ABC  "},
        {"%U", '\n', `U+000A`},
        {"%#U", '\n', `U+000A`},
        {"%U", 'x', `U+0078`},
        {"%#U", 'x', `U+0078 'x'`},
        {"%U", '\u263a', `U+263A`},
        {"%#U", '\u263a', `U+263A '☺'`},

        // floats
        {"%+.3e", 0.0, "+0.000e+00"},
        {"%+.3e", 1.0, "+1.000e+00"},
        {"%+.3f", -1.0, "-1.000"},
        {"% .3E", -1.0, "-1.000E+00"},
        {"% .3e", 1.0, " 1.000e+00"},
        {"%+.3g", 0.0, "+0"},
        {"%+.3g", 1.0, "+1"},
        {"%+.3g", -1.0, "-1"},
        {"% .3g", -1.0, "-1"},
        {"% .3g", 1.0, " 1"},

        // complex values
        {"%+.3e", 0i, "(+0.000e+00+0.000e+00i)"},
        {"%+.3f", 0i, "(+0.000+0.000i)"},
        {"%+.3g", 0i, "(+0+0i)"},
        {"%+.3e", 1 + 2i, "(+1.000e+00+2.000e+00i)"},
        {"%+.3f", 1 + 2i, "(+1.000+2.000i)"},
        {"%+.3g", 1 + 2i, "(+1+2i)"},
        {"%.3e", 0i, "(0.000e+00+0.000e+00i)"},
        {"%.3f", 0i, "(0.000+0.000i)"},
        {"%.3g", 0i, "(0+0i)"},
        {"%.3e", 1 + 2i, "(1.000e+00+2.000e+00i)"},
        {"%.3f", 1 + 2i, "(1.000+2.000i)"},
        {"%.3g", 1 + 2i, "(1+2i)"},
        {"%.3e", -1 - 2i, "(-1.000e+00-2.000e+00i)"},
        {"%.3f", -1 - 2i, "(-1.000-2.000i)"},
        {"%.3g", -1 - 2i, "(-1-2i)"},
        {"% .3E", -1 - 2i, "(-1.000E+00-2.000E+00i)"},
        {"%+.3g", complex64(1 + 2i), "(+1+2i)"},
        {"%+.3g", complex128(1 + 2i), "(+1+2i)"},

        // erroneous formats
        {"", 2, "%!(EXTRA int=2)"},
        {"%d", "hello", "%!d(string=hello)"},

        // old test/fmt_test.go
        {"%d", 1234, "1234"},
        {"%d", -1234, "-1234"},
        {"%d", uint(1234), "1234"},
        {"%d", uint32(b32), "4294967295"},
        {"%d", uint64(b64), "18446744073709551615"},
        {"%o", 01234, "1234"},
        {"%#o", 01234, "01234"},
        {"%o", uint32(b32), "37777777777"},
        {"%o", uint64(b64), "1777777777777777777777"},
        {"%x", 0x1234abcd, "1234abcd"},
        {"%#x", 0x1234abcd, "0x1234abcd"},
        {"%x", b32 - 0x1234567, "fedcba98"},
        {"%X", 0x1234abcd, "1234ABCD"},
        {"%X", b32 - 0x1234567, "FEDCBA98"},
        {"%#X", 0, "0X0"},
        {"%x", b64, "ffffffffffffffff"},
        {"%b", 7, "111"},
        {"%b", b64, "1111111111111111111111111111111111111111111111111111111111111111"},
        {"%b", -6, "-110"},
        {"%e", 1.0, "1.000000e+00"},
        {"%e", 1234.5678e3, "1.234568e+06"},
        {"%e", 1234.5678e-8, "1.234568e-05"},
        {"%e", -7.0, "-7.000000e+00"},
        {"%e", -1e-9, "-1.000000e-09"},
        {"%f", 1234.5678e3, "1234567.800000"},
        {"%f", 1234.5678e-8, "0.000012"},
        {"%f", -7.0, "-7.000000"},
        {"%f", -1e-9, "-0.000000"},
        {"%g", 1234.5678e3, "1.2345678e+06"},
        {"%g", float32(1234.5678e3), "1.2345678e+06"},
        {"%g", 1234.5678e-8, "1.2345678e-05"},
        {"%g", -7.0, "-7"},
        {"%g", -1e-9, "-1e-09"},
        {"%g", float32(-1e-9), "-1e-09"},
        {"%E", 1.0, "1.000000E+00"},
        {"%E", 1234.5678e3, "1.234568E+06"},
        {"%E", 1234.5678e-8, "1.234568E-05"},
        {"%E", -7.0, "-7.000000E+00"},
        {"%E", -1e-9, "-1.000000E-09"},
        {"%G", 1234.5678e3, "1.2345678E+06"},
        {"%G", float32(1234.5678e3), "1.2345678E+06"},
        {"%G", 1234.5678e-8, "1.2345678E-05"},
        {"%G", -7.0, "-7"},
        {"%G", -1e-9, "-1E-09"},
        {"%G", float32(-1e-9), "-1E-09"},
        {"%c", 'x', "x"},
        {"%c", 0xe4, "ä"},
        {"%c", 0x672c, "本"},
        {"%c", '日', "日"},
        {"%20.8d", 1234, "            00001234"},
        {"%20.8d", -1234, "           -00001234"},
        {"%20d", 1234, "                1234"},
        {"%-20.8d", 1234, "00001234            "},
        {"%-20.8d", -1234, "-00001234           "},
        {"%-#20.8x", 0x1234abc, "0x01234abc          "},
        {"%-#20.8X", 0x1234abc, "0X01234ABC          "},
        {"%-#20.8o", 01234, "00001234            "},
        {"%.20b", 7, "00000000000000000111"},
        {"%20.5s", "qwertyuiop", "               qwert"},
        {"%.5s", "qwertyuiop", "qwert"},
        {"%-20.5s", "qwertyuiop", "qwert               "},
        {"%20c", 'x', "                   x"},
        {"%-20c", 'x', "x                   "},
        {"%20.6e", 1.2345e3, "        1.234500e+03"},
        {"%20.6e", 1.2345e-3, "        1.234500e-03"},
        {"%20e", 1.2345e3, "        1.234500e+03"},
        {"%20e", 1.2345e-3, "        1.234500e-03"},
        {"%20.8e", 1.2345e3, "      1.23450000e+03"},
        {"%20f", 1.23456789e3, "         1234.567890"},
        {"%20f", 1.23456789e-3, "            0.001235"},
        {"%20f", 12345678901.23456789, "  12345678901.234568"},
        {"%-20f", 1.23456789e3, "1234.567890         "},
        {"%20.8f", 1.23456789e3, "       1234.56789000"},
        {"%20.8f", 1.23456789e-3, "          0.00123457"},
        {"%g", 1.23456789e3, "1234.56789"},
        {"%g", 1.23456789e-3, "0.00123456789"},
        {"%g", 1.23456789e20, "1.23456789e+20"},
        {"%20e", math.Inf(1), "                +Inf"},
        {"%-20f", math.Inf(-1), "-Inf                "},
        {"%20g", math.NaN(), "                 NaN"},

        // arrays
        {"%v", array, "[1 2 3 4 5]"},
        {"%v", iarray, "[1 hello 2.5 <nil>]"},
        {"%v", &array, "&[1 2 3 4 5]"},
        {"%v", &iarray, "&[1 hello 2.5 <nil>]"},

        // slices
        {"%v", slice, "[1 2 3 4 5]"},
        {"%v", islice, "[1 hello 2.5 <nil>]"},
        {"%v", &slice, "&[1 2 3 4 5]"},
        {"%v", &islice, "&[1 hello 2.5 <nil>]"},

        // complexes with %v
        {"%v", 1 + 2i, "(1+2i)"},
        {"%v", complex64(1 + 2i), "(1+2i)"},
        {"%v", complex128(1 + 2i), "(1+2i)"},

        // structs
        {"%v", A{1, 2, "a", []int{1, 2}}, `{1 2 a [1 2]}`},
        {"%+v", A{1, 2, "a", []int{1, 2}}, `{i:1 j:2 s:a x:[1 2]}`},

        // +v on structs with Stringable items
        {"%+v", B{1, 2}, `{I:<1> j:2}`},
        {"%+v", C{1, B{2, 3}}, `{i:1 B:{I:<2> j:3}}`},

        // q on Stringable items
        {"%s", I(23), `<23>`},
        {"%q", I(23), `"<23>"`},
        {"%x", I(23), `3c32333e`},
        {"%d", I(23), `23`}, // Stringer applies only to string formats.

        // go syntax
        {"%#v", A{1, 2, "a", []int{1, 2}}, `fmt_test.A{i:1, j:0x2, s:"a", x:[]int{1, 2}}`},
        {"%#v", &b, "(*uint8)(0xPTR)"},
        {"%#v", TestFmtInterface, "(func(*testing.T))(0xPTR)"},
        {"%#v", make(chan int), "(chan int)(0xPTR)"},
        {"%#v", uint64(1<<64 - 1), "0xffffffffffffffff"},
        {"%#v", 1000000000, "1000000000"},
        {"%#v", map[string]int{"a": 1}, `map[string]int{"a":1}`},
        {"%#v", map[string]B{"a": {1, 2}}, `map[string]fmt_test.B{"a":fmt_test.B{I:1, j:2}}`},
        {"%#v", []string{"a", "b"}, `[]string{"a", "b"}`},
        {"%#v", SI{}, `fmt_test.SI{I:interface {}(nil)}`},
        {"%#v", []int(nil), `[]int(nil)`},
        {"%#v", []int{}, `[]int{}`},
        {"%#v", array, `[5]int{1, 2, 3, 4, 5}`},
        {"%#v", &array, `&[5]int{1, 2, 3, 4, 5}`},
        {"%#v", iarray, `[4]interface {}{1, "hello", 2.5, interface {}(nil)}`},
        {"%#v", &iarray, `&[4]interface {}{1, "hello", 2.5, interface {}(nil)}`},
        {"%#v", map[int]byte(nil), `map[int]uint8(nil)`},
        {"%#v", map[int]byte{}, `map[int]uint8{}`},

        // slices with other formats
        {"%#x", []int{1, 2, 15}, `[0x1 0x2 0xf]`},
        {"%x", []int{1, 2, 15}, `[1 2 f]`},
        {"%d", []int{1, 2, 15}, `[1 2 15]`},
        {"%d", []byte{1, 2, 15}, `[1 2 15]`},
        {"%q", []string{"a", "b"}, `["a" "b"]`},

        // renamings
        {"%v", renamedBool(true), "true"},
        {"%d", renamedBool(true), "%!d(fmt_test.renamedBool=true)"},
        {"%o", renamedInt(8), "10"},
        {"%d", renamedInt8(-9), "-9"},
        {"%v", renamedInt16(10), "10"},
        {"%v", renamedInt32(-11), "-11"},
        {"%X", renamedInt64(255), "FF"},
        {"%v", renamedUint(13), "13"},
        {"%o", renamedUint8(14), "16"},
        {"%X", renamedUint16(15), "F"},
        {"%d", renamedUint32(16), "16"},
        {"%X", renamedUint64(17), "11"},
        {"%o", renamedUintptr(18), "22"},
        {"%x", renamedString("thing"), "7468696e67"},
        {"%d", renamedBytes([]byte{1, 2, 15}), `[1 2 15]`},
        {"%q", renamedBytes([]byte("hello")), `"hello"`},
        {"%v", renamedFloat32(22), "22"},
        {"%v", renamedFloat64(33), "33"},
        {"%v", renamedComplex64(3 + 4i), "(3+4i)"},
        {"%v", renamedComplex128(4 - 3i), "(4-3i)"},

        // Formatter
        {"%x", F(1), "<x=F(1)>"},
        {"%x", G(2), "2"},
        {"%+v", S{F(4), G(5)}, "{F:<v=F(4)> G:5}"},

        // GoStringer
        {"%#v", G(6), "GoString(6)"},
        {"%#v", S{F(7), G(8)}, "fmt_test.S{F:<v=F(7)>, G:GoString(8)}"},

        // %T
        {"%T", (4 - 3i), "complex128"},
        {"%T", renamedComplex128(4 - 3i), "fmt_test.renamedComplex128"},
        {"%T", intVal, "int"},
        {"%6T", &intVal, "  *int"},

        // %p
        {"p0=%p", new(int), "p0=0xPTR"},
        {"p1=%s", &pValue, "p1=String(p)"}, // String method...
        {"p2=%p", &pValue, "p2=0xPTR"},     // ... not called with %p
        {"p4=%#p", new(int), "p4=PTR"},

        // %p on non-pointers
        {"%p", make(chan int), "0xPTR"},
        {"%p", make(map[int]int), "0xPTR"},
        {"%p", make([]int, 1), "0xPTR"},
        {"%p", 27, "%!p(int=27)"}, // not a pointer at all

        // %d on Stringer should give integer if possible
        {"%s", time.Time{}.Month(), "January"},
        {"%d", time.Time{}.Month(), "1"},

        // erroneous things
        {"%s %", "hello", "hello %!(NOVERB)"},
        {"%s %.2", "hello", "hello %!(NOVERB)"},
        {"%d", "hello", "%!d(string=hello)"},
        {"no args", "hello", "no args%!(EXTRA string=hello)"},
        {"%s", nil, "%!s(<nil>)"},
        {"%T", nil, "<nil>"},
        {"%-1", 100, "%!(NOVERB)%!(EXTRA int=100)"},

        // The "<nil>" show up because maps are printed by
        // first obtaining a list of keys and then looking up
        // each key.  Since NaNs can be map keys but cannot
        // be fetched directly, the lookup fails and returns a
        // zero reflect.Value, which formats as <nil>.
        // This test is just to check that it shows the two NaNs at all.
        {"%v", map[float64]int{math.NaN(): 1, math.NaN(): 2}, "map[NaN:<nil> NaN:<nil>]"},
}

func TestSprintf(t *testing.T) {
        for _, tt := range fmttests {
                s := Sprintf(tt.fmt, tt.val)
                if i := strings.Index(tt.out, "PTR"); i >= 0 {
                        j := i
                        for ; j < len(s); j++ {
                                c := s[j]
                                if (c < '0' || c > '9') && (c < 'a' || c > 'f') && (c < 'A' || c > 'F') {
                                        break
                                }
                        }
                        s = s[0:i] + "PTR" + s[j:]
                }
                if s != tt.out {
                        if _, ok := tt.val.(string); ok {
                                // Don't requote the already-quoted strings.
                                // It's too confusing to read the errors.
                                t.Errorf("Sprintf(%q, %q) = <%s> want <%s>", tt.fmt, tt.val, s, tt.out)
                        } else {
                                t.Errorf("Sprintf(%q, %v) = %q want %q", tt.fmt, tt.val, s, tt.out)
                        }
                }
        }
}

func BenchmarkSprintfEmpty(b *testing.B) {
        for i := 0; i < b.N; i++ {
                Sprintf("")
        }
}

func BenchmarkSprintfString(b *testing.B) {
        for i := 0; i < b.N; i++ {
                Sprintf("%s", "hello")
        }
}

func BenchmarkSprintfInt(b *testing.B) {
        for i := 0; i < b.N; i++ {
                Sprintf("%d", 5)
        }
}

func BenchmarkSprintfIntInt(b *testing.B) {
        for i := 0; i < b.N; i++ {
                Sprintf("%d %d", 5, 6)
        }
}

func BenchmarkSprintfPrefixedInt(b *testing.B) {
        for i := 0; i < b.N; i++ {
                Sprintf("This is some meaningless prefix text that needs to be scanned %d", 6)
        }
}

func BenchmarkSprintfFloat(b *testing.B) {
        for i := 0; i < b.N; i++ {
                Sprintf("%g", 5.23184)
        }
}

var mallocBuf bytes.Buffer

// gccgo numbers are different because gccgo does not have escape
// analysis yet.
var mallocTest = []struct {
        count int
        desc  string
        fn    func()
}{
        {5, `Sprintf("")`, func() { Sprintf("") }},
        {5, `Sprintf("xxx")`, func() { Sprintf("xxx") }},
        {5, `Sprintf("%x")`, func() { Sprintf("%x", 7) }},
        {5, `Sprintf("%s")`, func() { Sprintf("%s", "hello") }},
        {5, `Sprintf("%x %x")`, func() { Sprintf("%x %x", 7, 112) }},
        // For %g we use a float32, not float64, to guarantee passing the argument
        // does not need to allocate memory to store the result in a pointer-sized word.
        {20, `Sprintf("%g")`, func() { Sprintf("%g", float32(3.14159)) }},
        {5, `Fprintf(buf, "%x %x %x")`, func() { mallocBuf.Reset(); Fprintf(&mallocBuf, "%x %x %x", 7, 8, 9) }},
        {5, `Fprintf(buf, "%s")`, func() { mallocBuf.Reset(); Fprintf(&mallocBuf, "%s", "hello") }},
}

var _ bytes.Buffer

func TestCountMallocs(t *testing.T) {
        for _, mt := range mallocTest {
                const N = 100
                memstats := new(runtime.MemStats)
                runtime.ReadMemStats(memstats)
                mallocs := 0 - memstats.Mallocs
                for i := 0; i < N; i++ {
                        mt.fn()
                }
                runtime.ReadMemStats(memstats)
                mallocs += memstats.Mallocs
                if mallocs/N > uint64(mt.count) {
                        t.Errorf("%s: expected %d mallocs, got %d", mt.desc, mt.count, mallocs/N)
                }
        }
}

type flagPrinter struct{}

func (*flagPrinter) Format(f State, c rune) {
        s := "%"
        for i := 0; i < 128; i++ {
                if f.Flag(i) {
                        s += string(i)
                }
        }
        if w, ok := f.Width(); ok {
                s += Sprintf("%d", w)
        }
        if p, ok := f.Precision(); ok {
                s += Sprintf(".%d", p)
        }
        s += string(c)
        io.WriteString(f, "["+s+"]")
}

var flagtests = []struct {
        in  string
        out string
}{
        {"%a", "[%a]"},
        {"%-a", "[%-a]"},
        {"%+a", "[%+a]"},
        {"%#a", "[%#a]"},
        {"% a", "[% a]"},
        {"%0a", "[%0a]"},
        {"%1.2a", "[%1.2a]"},
        {"%-1.2a", "[%-1.2a]"},
        {"%+1.2a", "[%+1.2a]"},
        {"%-+1.2a", "[%+-1.2a]"},
        {"%-+1.2abc", "[%+-1.2a]bc"},
        {"%-1.2abc", "[%-1.2a]bc"},
}

func TestFlagParser(t *testing.T) {
        var flagprinter flagPrinter
        for _, tt := range flagtests {
                s := Sprintf(tt.in, &flagprinter)
                if s != tt.out {
                        t.Errorf("Sprintf(%q, &flagprinter) => %q, want %q", tt.in, s, tt.out)
                }
        }
}

func TestStructPrinter(t *testing.T) {
        var s struct {
                a string
                b string
                c int
        }
        s.a = "abc"
        s.b = "def"
        s.c = 123
        var tests = []struct {
                fmt string
                out string
        }{
                {"%v", "{abc def 123}"},
                {"%+v", "{a:abc b:def c:123}"},
        }
        for _, tt := range tests {
                out := Sprintf(tt.fmt, s)
                if out != tt.out {
                        t.Errorf("Sprintf(%q, &s) = %q, want %q", tt.fmt, out, tt.out)
                }
        }
}

// Check map printing using substrings so we don't depend on the print order.
func presentInMap(s string, a []string, t *testing.T) {
        for i := 0; i < len(a); i++ {
                loc := strings.Index(s, a[i])
                if loc < 0 {
                        t.Errorf("map print: expected to find %q in %q", a[i], s)
                }
                // make sure the match ends here
                loc += len(a[i])
                if loc >= len(s) || (s[loc] != ' ' && s[loc] != ']') {
                        t.Errorf("map print: %q not properly terminated in %q", a[i], s)
                }
        }
}

func TestMapPrinter(t *testing.T) {
        m0 := make(map[int]string)
        s := Sprint(m0)
        if s != "map[]" {
                t.Errorf("empty map printed as %q not %q", s, "map[]")
        }
        m1 := map[int]string{1: "one", 2: "two", 3: "three"}
        a := []string{"1:one", "2:two", "3:three"}
        presentInMap(Sprintf("%v", m1), a, t)
        presentInMap(Sprint(m1), a, t)
}

func TestEmptyMap(t *testing.T) {
        const emptyMapStr = "map[]"
        var m map[string]int
        s := Sprint(m)
        if s != emptyMapStr {
                t.Errorf("nil map printed as %q not %q", s, emptyMapStr)
        }
        m = make(map[string]int)
        s = Sprint(m)
        if s != emptyMapStr {
                t.Errorf("empty map printed as %q not %q", s, emptyMapStr)
        }
}

// Check that Sprint (and hence Print, Fprint) puts spaces in the right places,
// that is, between arg pairs in which neither is a string.
func TestBlank(t *testing.T) {
        got := Sprint("<", 1, ">:", 1, 2, 3, "!")
        expect := "<1>:1 2 3!"
        if got != expect {
                t.Errorf("got %q expected %q", got, expect)
        }
}

// Check that Sprintln (and hence Println, Fprintln) puts spaces in the right places,
// that is, between all arg pairs.
func TestBlankln(t *testing.T) {
        got := Sprintln("<", 1, ">:", 1, 2, 3, "!")
        expect := "< 1 >: 1 2 3 !\n"
        if got != expect {
                t.Errorf("got %q expected %q", got, expect)
        }
}

// Check Formatter with Sprint, Sprintln, Sprintf
func TestFormatterPrintln(t *testing.T) {
        f := F(1)
        expect := "<v=F(1)>\n"
        s := Sprint(f, "\n")
        if s != expect {
                t.Errorf("Sprint wrong with Formatter: expected %q got %q", expect, s)
        }
        s = Sprintln(f)
        if s != expect {
                t.Errorf("Sprintln wrong with Formatter: expected %q got %q", expect, s)
        }
        s = Sprintf("%v\n", f)
        if s != expect {
                t.Errorf("Sprintf wrong with Formatter: expected %q got %q", expect, s)
        }
}

func args(a ...interface{}) []interface{} { return a }

var startests = []struct {
        fmt string
        in  []interface{}
        out string
}{
        {"%*d", args(4, 42), "  42"},
        {"%.*d", args(4, 42), "0042"},
        {"%*.*d", args(8, 4, 42), "    0042"},
        {"%0*d", args(4, 42), "0042"},
        {"%-*d", args(4, 42), "42  "},

        // erroneous
        {"%*d", args(nil, 42), "%!(BADWIDTH)42"},
        {"%.*d", args(nil, 42), "%!(BADPREC)42"},
        {"%*d", args(5, "foo"), "%!d(string=  foo)"},
        {"%*% %d", args(20, 5), "% 5"},
        {"%*", args(4), "%!(NOVERB)"},
        {"%*d", args(int32(4), 42), "%!(BADWIDTH)42"},
}

func TestWidthAndPrecision(t *testing.T) {
        for _, tt := range startests {
                s := Sprintf(tt.fmt, tt.in...)
                if s != tt.out {
                        t.Errorf("%q: got %q expected %q", tt.fmt, s, tt.out)
                }
        }
}

// A type that panics in String.
type Panic struct {
        message interface{}
}

// Value receiver.
func (p Panic) GoString() string {
        panic(p.message)
}

// Value receiver.
func (p Panic) String() string {
        panic(p.message)
}

// A type that panics in Format.
type PanicF struct {
        message interface{}
}

// Value receiver.
func (p PanicF) Format(f State, c rune) {
        panic(p.message)
}

var panictests = []struct {
        fmt string
        in  interface{}
        out string
}{
        // String
        {"%s", (*Panic)(nil), "<nil>"}, // nil pointer special case
        {"%s", Panic{io.ErrUnexpectedEOF}, "%s(PANIC=unexpected EOF)"},
        {"%s", Panic{3}, "%s(PANIC=3)"},
        // GoString
        {"%#v", (*Panic)(nil), "<nil>"}, // nil pointer special case
        {"%#v", Panic{io.ErrUnexpectedEOF}, "%v(PANIC=unexpected EOF)"},
        {"%#v", Panic{3}, "%v(PANIC=3)"},
        // Format
        {"%s", (*PanicF)(nil), "<nil>"}, // nil pointer special case
        {"%s", PanicF{io.ErrUnexpectedEOF}, "%s(PANIC=unexpected EOF)"},
        {"%s", PanicF{3}, "%s(PANIC=3)"},
}

func TestPanics(t *testing.T) {
        for _, tt := range panictests {
                s := Sprintf(tt.fmt, tt.in)
                if s != tt.out {
                        t.Errorf("%q: got %q expected %q", tt.fmt, s, tt.out)
                }
        }
}

// Test that erroneous String routine doesn't cause fatal recursion.
var recurCount = 0

type Recur struct {
        i      int
        failed *bool
}

func (r Recur) String() string {
        if recurCount++; recurCount > 10 {
                *r.failed = true
                return "FAIL"
        }
        // This will call badVerb. Before the fix, that would cause us to recur into
        // this routine to print %!p(value). Now we don't call the user's method
        // during an error.
        return Sprintf("recur@%p value: %d", r, r.i)
}

func TestBadVerbRecursion(t *testing.T) {
        failed := false
        r := Recur{3, &failed}
        Sprintf("recur@%p value: %d\n", &r, r.i)
        if failed {
                t.Error("fail with pointer")
        }
        failed = false
        r = Recur{4, &failed}
        Sprintf("recur@%p, value: %d\n", r, r.i)
        if failed {
                t.Error("fail with value")
        }
}