1 files changed, 214 insertions, 0 deletions
diff --git a/src/encoding/ascii85/ascii85_test.go b/src/encoding/ascii85/ascii85_test.go
new file mode 100644
index 0000000..578829e
--- /dev/null
+++ b/src/encoding/ascii85/ascii85_test.go
@@ -0,0 +1,214 @@
+// 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 ascii85
+
+import (
+	"bytes"
+	"io"
+	"strings"
+	"testing"
+)
+
+type testpair struct {
+	decoded, encoded string
+}
+
+var bigtest = testpair{
+	"Man is distinguished, not only by his reason, but by this singular passion from " +
+		"other animals, which is a lust of the mind, that by a perseverance of delight in " +
+		"the continued and indefatigable generation of knowledge, exceeds the short " +
+		"vehemence of any carnal pleasure.",
+	"9jqo^BlbD-BleB1DJ+*+F(f,q/0JhKF<GL>Cj@.4Gp$d7F!,L7@<6@)/0JDEF<G%<+EV:2F!,\n" +
+		"O<DJ+*.@<*K0@<6L(Df-\\0Ec5e;DffZ(EZee.Bl.9pF\"AGXBPCsi+DGm>@3BB/F*&OCAfu2/AKY\n" +
+		"i(DIb:@FD,*)+C]U=@3BN#EcYf8ATD3s@q?d$AftVqCh[NqF<G:8+EV:.+Cf>-FD5W8ARlolDIa\n" +
+		"l(DId<j@<?3r@:F%a+D58'ATD4$Bl@l3De:,-DJs`8ARoFb/0JMK@qB4^F!,R<AKZ&-DfTqBG%G\n" +
+		">uD.RTpAKYo'+CT/5+Cei#DII?(E,9)oF*2M7/c\n",
+}
+
+var pairs = []testpair{
+	// Encode returns 0 when len(src) is 0
+	{
+		"",
+		"",
+	},
+	// Wikipedia example
+	bigtest,
+	// Special case when shortening !!!!! to z.
+	{
+		"\000\000\000\000",
+		"z",
+	},
+}
+
+func testEqual(t *testing.T, msg string, args ...any) bool {
+	t.Helper()
+	if args[len(args)-2] != args[len(args)-1] {
+		t.Errorf(msg, args...)
+		return false
+	}
+	return true
+}
+
+func strip85(s string) string {
+	t := make([]byte, len(s))
+	w := 0
+	for r := 0; r < len(s); r++ {
+		c := s[r]
+		if c > ' ' {
+			t[w] = c
+			w++
+		}
+	}
+	return string(t[0:w])
+}
+
+func TestEncode(t *testing.T) {
+	for _, p := range pairs {
+		buf := make([]byte, MaxEncodedLen(len(p.decoded)))
+		n := Encode(buf, []byte(p.decoded))
+		buf = buf[0:n]
+		testEqual(t, "Encode(%q) = %q, want %q", p.decoded, strip85(string(buf)), strip85(p.encoded))
+	}
+}
+
+func TestEncoder(t *testing.T) {
+	for _, p := range pairs {
+		bb := &strings.Builder{}
+		encoder := NewEncoder(bb)
+		encoder.Write([]byte(p.decoded))
+		encoder.Close()
+		testEqual(t, "Encode(%q) = %q, want %q", p.decoded, strip85(bb.String()), strip85(p.encoded))
+	}
+}
+
+func TestEncoderBuffering(t *testing.T) {
+	input := []byte(bigtest.decoded)
+	for bs := 1; bs <= 12; bs++ {
+		bb := &strings.Builder{}
+		encoder := NewEncoder(bb)
+		for pos := 0; pos < len(input); pos += bs {
+			end := pos + bs
+			if end > len(input) {
+				end = len(input)
+			}
+			n, err := encoder.Write(input[pos:end])
+			testEqual(t, "Write(%q) gave error %v, want %v", input[pos:end], err, error(nil))
+			testEqual(t, "Write(%q) gave length %v, want %v", input[pos:end], n, end-pos)
+		}
+		err := encoder.Close()
+		testEqual(t, "Close gave error %v, want %v", err, error(nil))
+		testEqual(t, "Encoding/%d of %q = %q, want %q", bs, bigtest.decoded, strip85(bb.String()), strip85(bigtest.encoded))
+	}
+}
+
+func TestDecode(t *testing.T) {
+	for _, p := range pairs {
+		dbuf := make([]byte, 4*len(p.encoded))
+		ndst, nsrc, err := Decode(dbuf, []byte(p.encoded), true)
+		testEqual(t, "Decode(%q) = error %v, want %v", p.encoded, err, error(nil))
+		testEqual(t, "Decode(%q) = nsrc %v, want %v", p.encoded, nsrc, len(p.encoded))
+		testEqual(t, "Decode(%q) = ndst %v, want %v", p.encoded, ndst, len(p.decoded))
+		testEqual(t, "Decode(%q) = %q, want %q", p.encoded, string(dbuf[0:ndst]), p.decoded)
+	}
+}
+
+func TestDecoder(t *testing.T) {
+	for _, p := range pairs {
+		decoder := NewDecoder(strings.NewReader(p.encoded))
+		dbuf, err := io.ReadAll(decoder)
+		if err != nil {
+			t.Fatal("Read failed", err)
+		}
+		testEqual(t, "Read from %q = length %v, want %v", p.encoded, len(dbuf), len(p.decoded))
+		testEqual(t, "Decoding of %q = %q, want %q", p.encoded, string(dbuf), p.decoded)
+		if err != nil {
+			testEqual(t, "Read from %q = %v, want %v", p.encoded, err, io.EOF)
+		}
+	}
+}
+
+func TestDecoderBuffering(t *testing.T) {
+	for bs := 1; bs <= 12; bs++ {
+		decoder := NewDecoder(strings.NewReader(bigtest.encoded))
+		buf := make([]byte, len(bigtest.decoded)+12)
+		var total int
+		var n int
+		var err error
+		for total = 0; total < len(bigtest.decoded) && err == nil; {
+			n, err = decoder.Read(buf[total : total+bs])
+			total += n
+		}
+		if err != nil && err != io.EOF {
+			t.Errorf("Read from %q at pos %d = %d, unexpected error %v", bigtest.encoded, total, n, err)
+		}
+		testEqual(t, "Decoding/%d of %q = %q, want %q", bs, bigtest.encoded, string(buf[0:total]), bigtest.decoded)
+	}
+}
+
+func TestDecodeCorrupt(t *testing.T) {
+	type corrupt struct {
+		e string
+		p int
+	}
+	examples := []corrupt{
+		{"v", 0},
+		{"!z!!!!!!!!!", 1},
+	}
+
+	for _, e := range examples {
+		dbuf := make([]byte, 4*len(e.e))
+		_, _, err := Decode(dbuf, []byte(e.e), true)
+		switch err := err.(type) {
+		case CorruptInputError:
+			testEqual(t, "Corruption in %q at offset %v, want %v", e.e, int(err), e.p)
+		default:
+			t.Error("Decoder failed to detect corruption in", e)
+		}
+	}
+}
+
+func TestBig(t *testing.T) {
+	n := 3*1000 + 1
+	raw := make([]byte, n)
+	const alpha = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	for i := 0; i < n; i++ {
+		raw[i] = alpha[i%len(alpha)]
+	}
+	encoded := new(bytes.Buffer)
+	w := NewEncoder(encoded)
+	nn, err := w.Write(raw)
+	if nn != n || err != nil {
+		t.Fatalf("Encoder.Write(raw) = %d, %v want %d, nil", nn, err, n)
+	}
+	err = w.Close()
+	if err != nil {
+		t.Fatalf("Encoder.Close() = %v want nil", err)
+	}
+	decoded, err := io.ReadAll(NewDecoder(encoded))
+	if err != nil {
+		t.Fatalf("io.ReadAll(NewDecoder(...)): %v", err)
+	}
+
+	if !bytes.Equal(raw, decoded) {
+		var i int
+		for i = 0; i < len(decoded) && i < len(raw); i++ {
+			if decoded[i] != raw[i] {
+				break
+			}
+		}
+		t.Errorf("Decode(Encode(%d-byte string)) failed at offset %d", n, i)
+	}
+}
+
+func TestDecoderInternalWhitespace(t *testing.T) {
+	s := strings.Repeat(" ", 2048) + "z"
+	decoded, err := io.ReadAll(NewDecoder(strings.NewReader(s)))
+	if err != nil {
+		t.Errorf("Decode gave error %v", err)
+	}
+	if want := []byte("\000\000\000\000"); !bytes.Equal(want, decoded) {
+		t.Errorf("Decode failed: got %v, want %v", decoded, want)
+	}
+}