1 files changed, 304 insertions, 0 deletions
diff --git a/src/encoding/json/scanner_test.go b/src/encoding/json/scanner_test.go
new file mode 100644
index 0000000..068439d
--- /dev/null
+++ b/src/encoding/json/scanner_test.go
@@ -0,0 +1,304 @@
+// Copyright 2010 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 json
+
+import (
+	"bytes"
+	"math"
+	"math/rand"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+func indentNewlines(s string) string {
+	return strings.Join(strings.Split(s, "\n"), "\n\t")
+}
+
+func stripWhitespace(s string) string {
+	return strings.Map(func(r rune) rune {
+		if r == ' ' || r == '\n' || r == '\r' || r == '\t' {
+			return -1
+		}
+		return r
+	}, s)
+}
+
+func TestValid(t *testing.T) {
+	tests := []struct {
+		CaseName
+		data string
+		ok   bool
+	}{
+		{Name(""), `foo`, false},
+		{Name(""), `}{`, false},
+		{Name(""), `{]`, false},
+		{Name(""), `{}`, true},
+		{Name(""), `{"foo":"bar"}`, true},
+		{Name(""), `{"foo":"bar","bar":{"baz":["qux"]}}`, true},
+	}
+	for _, tt := range tests {
+		t.Run(tt.Name, func(t *testing.T) {
+			if ok := Valid([]byte(tt.data)); ok != tt.ok {
+				t.Errorf("%s: Valid(`%s`) = %v, want %v", tt.Where, tt.data, ok, tt.ok)
+			}
+		})
+	}
+}
+
+func TestCompactAndIndent(t *testing.T) {
+	tests := []struct {
+		CaseName
+		compact string
+		indent  string
+	}{
+		{Name(""), `1`, `1`},
+		{Name(""), `{}`, `{}`},
+		{Name(""), `[]`, `[]`},
+		{Name(""), `{"":2}`, "{\n\t\"\": 2\n}"},
+		{Name(""), `[3]`, "[\n\t3\n]"},
+		{Name(""), `[1,2,3]`, "[\n\t1,\n\t2,\n\t3\n]"},
+		{Name(""), `{"x":1}`, "{\n\t\"x\": 1\n}"},
+		{Name(""), `[true,false,null,"x",1,1.5,0,-5e+2]`, `[
+	true,
+	false,
+	null,
+	"x",
+	1,
+	1.5,
+	0,
+	-5e+2
+]`},
+		{Name(""), "{\"\":\"<>&\u2028\u2029\"}", "{\n\t\"\": \"<>&\u2028\u2029\"\n}"}, // See golang.org/issue/34070
+	}
+	var buf bytes.Buffer
+	for _, tt := range tests {
+		t.Run(tt.Name, func(t *testing.T) {
+			buf.Reset()
+			if err := Compact(&buf, []byte(tt.compact)); err != nil {
+				t.Errorf("%s: Compact error: %v", tt.Where, err)
+			} else if got := buf.String(); got != tt.compact {
+				t.Errorf("%s: Compact:\n\tgot:  %s\n\twant: %s", tt.Where, indentNewlines(got), indentNewlines(tt.compact))
+			}
+
+			buf.Reset()
+			if err := Compact(&buf, []byte(tt.indent)); err != nil {
+				t.Errorf("%s: Compact error: %v", tt.Where, err)
+			} else if got := buf.String(); got != tt.compact {
+				t.Errorf("%s: Compact:\n\tgot:  %s\n\twant: %s", tt.Where, indentNewlines(got), indentNewlines(tt.compact))
+			}
+
+			buf.Reset()
+			if err := Indent(&buf, []byte(tt.indent), "", "\t"); err != nil {
+				t.Errorf("%s: Indent error: %v", tt.Where, err)
+			} else if got := buf.String(); got != tt.indent {
+				t.Errorf("%s: Compact:\n\tgot:  %s\n\twant: %s", tt.Where, indentNewlines(got), indentNewlines(tt.indent))
+			}
+
+			buf.Reset()
+			if err := Indent(&buf, []byte(tt.compact), "", "\t"); err != nil {
+				t.Errorf("%s: Indent error: %v", tt.Where, err)
+			} else if got := buf.String(); got != tt.indent {
+				t.Errorf("%s: Compact:\n\tgot:  %s\n\twant: %s", tt.Where, indentNewlines(got), indentNewlines(tt.indent))
+			}
+		})
+	}
+}
+
+func TestCompactSeparators(t *testing.T) {
+	// U+2028 and U+2029 should be escaped inside strings.
+	// They should not appear outside strings.
+	tests := []struct {
+		CaseName
+		in, compact string
+	}{
+		{Name(""), "{\"\u2028\": 1}", "{\"\u2028\":1}"},
+		{Name(""), "{\"\u2029\" :2}", "{\"\u2029\":2}"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.Name, func(t *testing.T) {
+			var buf bytes.Buffer
+			if err := Compact(&buf, []byte(tt.in)); err != nil {
+				t.Errorf("%s: Compact error: %v", tt.Where, err)
+			} else if got := buf.String(); got != tt.compact {
+				t.Errorf("%s: Compact:\n\tgot:  %s\n\twant: %s", tt.Where, indentNewlines(got), indentNewlines(tt.compact))
+			}
+		})
+	}
+}
+
+// Tests of a large random structure.
+
+func TestCompactBig(t *testing.T) {
+	initBig()
+	var buf bytes.Buffer
+	if err := Compact(&buf, jsonBig); err != nil {
+		t.Fatalf("Compact error: %v", err)
+	}
+	b := buf.Bytes()
+	if !bytes.Equal(b, jsonBig) {
+		t.Error("Compact:")
+		diff(t, b, jsonBig)
+		return
+	}
+}
+
+func TestIndentBig(t *testing.T) {
+	t.Parallel()
+	initBig()
+	var buf bytes.Buffer
+	if err := Indent(&buf, jsonBig, "", "\t"); err != nil {
+		t.Fatalf("Indent error: %v", err)
+	}
+	b := buf.Bytes()
+	if len(b) == len(jsonBig) {
+		// jsonBig is compact (no unnecessary spaces);
+		// indenting should make it bigger
+		t.Fatalf("Indent did not expand the input")
+	}
+
+	// should be idempotent
+	var buf1 bytes.Buffer
+	if err := Indent(&buf1, b, "", "\t"); err != nil {
+		t.Fatalf("Indent error: %v", err)
+	}
+	b1 := buf1.Bytes()
+	if !bytes.Equal(b1, b) {
+		t.Error("Indent(Indent(jsonBig)) != Indent(jsonBig):")
+		diff(t, b1, b)
+		return
+	}
+
+	// should get back to original
+	buf1.Reset()
+	if err := Compact(&buf1, b); err != nil {
+		t.Fatalf("Compact error: %v", err)
+	}
+	b1 = buf1.Bytes()
+	if !bytes.Equal(b1, jsonBig) {
+		t.Error("Compact(Indent(jsonBig)) != jsonBig:")
+		diff(t, b1, jsonBig)
+		return
+	}
+}
+
+func TestIndentErrors(t *testing.T) {
+	tests := []struct {
+		CaseName
+		in  string
+		err error
+	}{
+		{Name(""), `{"X": "foo", "Y"}`, &SyntaxError{"invalid character '}' after object key", 17}},
+		{Name(""), `{"X": "foo" "Y": "bar"}`, &SyntaxError{"invalid character '\"' after object key:value pair", 13}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.Name, func(t *testing.T) {
+			slice := make([]uint8, 0)
+			buf := bytes.NewBuffer(slice)
+			if err := Indent(buf, []uint8(tt.in), "", ""); err != nil {
+				if !reflect.DeepEqual(err, tt.err) {
+					t.Fatalf("%s: Indent error:\n\tgot:  %v\n\twant: %v", tt.Where, err, tt.err)
+				}
+			}
+		})
+	}
+}
+
+func diff(t *testing.T, a, b []byte) {
+	t.Helper()
+	for i := 0; ; i++ {
+		if i >= len(a) || i >= len(b) || a[i] != b[i] {
+			j := i - 10
+			if j < 0 {
+				j = 0
+			}
+			t.Errorf("diverge at %d: «%s» vs «%s»", i, trim(a[j:]), trim(b[j:]))
+			return
+		}
+	}
+}
+
+func trim(b []byte) []byte {
+	return b[:min(len(b), 20)]
+}
+
+// Generate a random JSON object.
+
+var jsonBig []byte
+
+func initBig() {
+	n := 10000
+	if testing.Short() {
+		n = 100
+	}
+	b, err := Marshal(genValue(n))
+	if err != nil {
+		panic(err)
+	}
+	jsonBig = b
+}
+
+func genValue(n int) any {
+	if n > 1 {
+		switch rand.Intn(2) {
+		case 0:
+			return genArray(n)
+		case 1:
+			return genMap(n)
+		}
+	}
+	switch rand.Intn(3) {
+	case 0:
+		return rand.Intn(2) == 0
+	case 1:
+		return rand.NormFloat64()
+	case 2:
+		return genString(30)
+	}
+	panic("unreachable")
+}
+
+func genString(stddev float64) string {
+	n := int(math.Abs(rand.NormFloat64()*stddev + stddev/2))
+	c := make([]rune, n)
+	for i := range c {
+		f := math.Abs(rand.NormFloat64()*64 + 32)
+		if f > 0x10ffff {
+			f = 0x10ffff
+		}
+		c[i] = rune(f)
+	}
+	return string(c)
+}
+
+func genArray(n int) []any {
+	f := int(math.Abs(rand.NormFloat64()) * math.Min(10, float64(n/2)))
+	if f > n {
+		f = n
+	}
+	if f < 1 {
+		f = 1
+	}
+	x := make([]any, f)
+	for i := range x {
+		x[i] = genValue(((i+1)*n)/f - (i*n)/f)
+	}
+	return x
+}
+
+func genMap(n int) map[string]any {
+	f := int(math.Abs(rand.NormFloat64()) * math.Min(10, float64(n/2)))
+	if f > n {
+		f = n
+	}
+	if n > 0 && f == 0 {
+		f = 1
+	}
+	x := make(map[string]any)
+	for i := 0; i < f; i++ {
+		x[genString(10)] = genValue(((i+1)*n)/f - (i*n)/f)
+	}
+	return x
+}