diff --git a/append.go b/append.go
new file mode 100644
index 0000000..494b0b5
--- /dev/null
+++ b/append.go
@@ -0,0 +1,49 @@
+package htmlescape
+
+import (
+	"unicode/utf8"
+)
+
+func AppendBytes(p []byte, bytes []byte) ([]byte, error) {
+	for 0 < len(bytes) {
+		r, size := utf8.DecodeRune(bytes)
+		if utf8.RuneError == r && 1 == size {
+			return p, errNotUTF8
+		}
+		if size <= 0 {
+			return p, errInternalError
+		}
+		bytes = bytes[size:]
+
+		p = AppendRune(p, r)
+	}
+
+	return p, nil
+}
+
+func AppendRune(p []byte, r rune) []byte {
+
+	escapedRune, wasEscaped := safeRune(r)
+	if wasEscaped {
+		return append(p, escapedRune...)
+	}
+
+	return append(p, string(r)...)
+}
+
+func AppendString(p []byte, str string) ([]byte, error) {
+	for 0 < len(str) {
+		r, size := utf8.DecodeRuneInString(str)
+		if utf8.RuneError == r && 1 == size {
+			return p, errNotUTF8
+		}
+		if size <= 0 {
+			return p, errInternalError
+		}
+		str = str[size:]
+
+		p = AppendRune(p, r)
+	}
+
+	return p, nil
+}
diff --git a/appendbytes_test.go b/appendbytes_test.go
new file mode 100644
index 0000000..0ef8a2b
--- /dev/null
+++ b/appendbytes_test.go
@@ -0,0 +1,65 @@
+package htmlescape_test
+
+import (
+	"testing"
+
+	"bytes"
+
+	"sourcecode.social/reiver/go-htmlescape"
+)
+
+func TestAppendBytes(t *testing.T) {
+
+	tests := []struct{
+		Bytes []byte
+		Slice []byte
+		Expected []byte
+	}{
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Slice:                                         []byte("This is NOT <b>bold</b>!"),
+			Expected: []byte("Hello world! 🙂 Take a look at this: This is NOT &lt;b&gt;bold&lt;/b&gt;!"),
+		},
+
+
+
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Slice:                                         []byte(`"this is a quotation"`),
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#34;this is a quotation&#34;"),
+		},
+
+
+
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Slice:                                            []byte("\t3 < 5\r\n3 > 2\x00"),
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x9;3 &lt; 5&#xD;&#xA;3 &gt; 2&#x0;"),
+		},
+	}
+
+	for testNumber, test := range tests {
+
+		var p []byte = append([]byte(nil), test.Bytes...)
+		actual, err := htmlescape.AppendBytes(p, test.Slice)
+
+		if nil != err {
+			t.Errorf("For test #%d, did not expect to get an error but actually got one." , testNumber)
+			t.Logf("ERROR: (%T) %s", err, err)
+			t.Logf("SLICE: %q", test.Slice)
+			t.Logf("BYTES: %q", test.Bytes)
+			continue
+		}
+
+		expected := test.Expected
+
+		if !bytes.Equal(expected, actual) {
+			t.Errorf("For test #%d, the actual resulting value of the append is not what was expected.", testNumber)
+			t.Logf("EXPECTED: %q", expected)
+			t.Logf("ACTUAL:   %q", actual)
+			t.Logf("SLICE: %q", test.Slice)
+			t.Logf("BYTES: %q", test.Bytes)
+			continue
+		}
+	}
+}
diff --git a/appendrune_test.go b/appendrune_test.go
new file mode 100644
index 0000000..fc1d7d6
--- /dev/null
+++ b/appendrune_test.go
@@ -0,0 +1,841 @@
+package htmlescape_test
+
+import (
+	"testing"
+
+	"bytes"
+
+	"sourcecode.social/reiver/go-htmlescape"
+)
+
+func TestAppendRune(t *testing.T) {
+
+	tests := []struct{
+		Bytes []byte
+		Rune rune
+		Expected []byte
+	}{
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x00,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x0;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x01,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x1;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x02,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x2;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x03,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x3;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x04,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x4;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x05,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x5;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x06,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x6;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x07,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x7;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x08,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x8;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x09,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x9;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x0A,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#xA;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x0B,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#xB;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x0C,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#xC;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x0D,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#xD;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x0E,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#xE;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x0F,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#xF;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x10,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x10;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x11,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x11;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x12,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x12;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x13,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x13;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x14,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x14;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x15,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x15;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x16,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x16;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x17,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x17;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x18,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x18;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x19,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x19;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x1A,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x1A;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x1B,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x1B;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x1C,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x1C;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x1D,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x1D;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x1E,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x1E;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x1F,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x1F;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x20,
+			Expected: []byte("Hello world! 🙂 Take a look at this:  "),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x21,
+			Expected: []byte("Hello world! 🙂 Take a look at this: !"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x22,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#34;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x23,
+			Expected: []byte("Hello world! 🙂 Take a look at this: #"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x24,
+			Expected: []byte("Hello world! 🙂 Take a look at this: $"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x25,
+			Expected: []byte("Hello world! 🙂 Take a look at this: %"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x26,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &amp;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x27,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#39;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x28,
+			Expected: []byte("Hello world! 🙂 Take a look at this: ("),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x29,
+			Expected: []byte("Hello world! 🙂 Take a look at this: )"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x2A,
+			Expected: []byte("Hello world! 🙂 Take a look at this: *"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x2B,
+			Expected: []byte("Hello world! 🙂 Take a look at this: +"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x2C,
+			Expected: []byte("Hello world! 🙂 Take a look at this: ,"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x2D,
+			Expected: []byte("Hello world! 🙂 Take a look at this: -"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x2E,
+			Expected: []byte("Hello world! 🙂 Take a look at this: ."),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x2F,
+			Expected: []byte("Hello world! 🙂 Take a look at this: /"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x30,
+			Expected: []byte("Hello world! 🙂 Take a look at this: 0"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x31,
+			Expected: []byte("Hello world! 🙂 Take a look at this: 1"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x32,
+			Expected: []byte("Hello world! 🙂 Take a look at this: 2"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x33,
+			Expected: []byte("Hello world! 🙂 Take a look at this: 3"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x34,
+			Expected: []byte("Hello world! 🙂 Take a look at this: 4"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x35,
+			Expected: []byte("Hello world! 🙂 Take a look at this: 5"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x36,
+			Expected: []byte("Hello world! 🙂 Take a look at this: 6"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x37,
+			Expected: []byte("Hello world! 🙂 Take a look at this: 7"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x38,
+			Expected: []byte("Hello world! 🙂 Take a look at this: 8"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x39,
+			Expected: []byte("Hello world! 🙂 Take a look at this: 9"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x3A,
+			Expected: []byte("Hello world! 🙂 Take a look at this: :"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x3B,
+			Expected: []byte("Hello world! 🙂 Take a look at this: ;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x3C,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &lt;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x3D,
+			Expected: []byte("Hello world! 🙂 Take a look at this: ="),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x3E,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &gt;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x3F,
+			Expected: []byte("Hello world! 🙂 Take a look at this: ?"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x40,
+			Expected: []byte("Hello world! 🙂 Take a look at this: @"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x41,
+			Expected: []byte("Hello world! 🙂 Take a look at this: A"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x42,
+			Expected: []byte("Hello world! 🙂 Take a look at this: B"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x43,
+			Expected: []byte("Hello world! 🙂 Take a look at this: C"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x44,
+			Expected: []byte("Hello world! 🙂 Take a look at this: D"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x45,
+			Expected: []byte("Hello world! 🙂 Take a look at this: E"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x46,
+			Expected: []byte("Hello world! 🙂 Take a look at this: F"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x47,
+			Expected: []byte("Hello world! 🙂 Take a look at this: G"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x48,
+			Expected: []byte("Hello world! 🙂 Take a look at this: H"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x49,
+			Expected: []byte("Hello world! 🙂 Take a look at this: I"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x4A,
+			Expected: []byte("Hello world! 🙂 Take a look at this: J"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x4B,
+			Expected: []byte("Hello world! 🙂 Take a look at this: K"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x4C,
+			Expected: []byte("Hello world! 🙂 Take a look at this: L"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x4D,
+			Expected: []byte("Hello world! 🙂 Take a look at this: M"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x4E,
+			Expected: []byte("Hello world! 🙂 Take a look at this: N"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x4F,
+			Expected: []byte("Hello world! 🙂 Take a look at this: O"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x50,
+			Expected: []byte("Hello world! 🙂 Take a look at this: P"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x51,
+			Expected: []byte("Hello world! 🙂 Take a look at this: Q"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x52,
+			Expected: []byte("Hello world! 🙂 Take a look at this: R"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x53,
+			Expected: []byte("Hello world! 🙂 Take a look at this: S"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x54,
+			Expected: []byte("Hello world! 🙂 Take a look at this: T"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x55,
+			Expected: []byte("Hello world! 🙂 Take a look at this: U"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x56,
+			Expected: []byte("Hello world! 🙂 Take a look at this: V"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x57,
+			Expected: []byte("Hello world! 🙂 Take a look at this: W"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x58,
+			Expected: []byte("Hello world! 🙂 Take a look at this: X"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x59,
+			Expected: []byte("Hello world! 🙂 Take a look at this: Y"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x5A,
+			Expected: []byte("Hello world! 🙂 Take a look at this: Z"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x5B,
+			Expected: []byte("Hello world! 🙂 Take a look at this: ["),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x5C,
+			Expected: []byte("Hello world! 🙂 Take a look at this: \\"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x5D,
+			Expected: []byte("Hello world! 🙂 Take a look at this: ]"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x5E,
+			Expected: []byte("Hello world! 🙂 Take a look at this: ^"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x5F,
+			Expected: []byte("Hello world! 🙂 Take a look at this: _"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x60,
+			Expected: []byte("Hello world! 🙂 Take a look at this: `"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x61,
+			Expected: []byte("Hello world! 🙂 Take a look at this: a"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x62,
+			Expected: []byte("Hello world! 🙂 Take a look at this: b"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x63,
+			Expected: []byte("Hello world! 🙂 Take a look at this: c"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x64,
+			Expected: []byte("Hello world! 🙂 Take a look at this: d"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x65,
+			Expected: []byte("Hello world! 🙂 Take a look at this: e"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x66,
+			Expected: []byte("Hello world! 🙂 Take a look at this: f"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x67,
+			Expected: []byte("Hello world! 🙂 Take a look at this: g"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x68,
+			Expected: []byte("Hello world! 🙂 Take a look at this: h"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x69,
+			Expected: []byte("Hello world! 🙂 Take a look at this: i"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x6A,
+			Expected: []byte("Hello world! 🙂 Take a look at this: j"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x6B,
+			Expected: []byte("Hello world! 🙂 Take a look at this: k"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x6C,
+			Expected: []byte("Hello world! 🙂 Take a look at this: l"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x6D,
+			Expected: []byte("Hello world! 🙂 Take a look at this: m"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x6E,
+			Expected: []byte("Hello world! 🙂 Take a look at this: n"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x6F,
+			Expected: []byte("Hello world! 🙂 Take a look at this: o"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x70,
+			Expected: []byte("Hello world! 🙂 Take a look at this: p"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x71,
+			Expected: []byte("Hello world! 🙂 Take a look at this: q"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x72,
+			Expected: []byte("Hello world! 🙂 Take a look at this: r"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x73,
+			Expected: []byte("Hello world! 🙂 Take a look at this: s"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x74,
+			Expected: []byte("Hello world! 🙂 Take a look at this: t"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x75,
+			Expected: []byte("Hello world! 🙂 Take a look at this: u"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x76,
+			Expected: []byte("Hello world! 🙂 Take a look at this: v"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x77,
+			Expected: []byte("Hello world! 🙂 Take a look at this: w"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x78,
+			Expected: []byte("Hello world! 🙂 Take a look at this: x"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x79,
+			Expected: []byte("Hello world! 🙂 Take a look at this: y"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x7A,
+			Expected: []byte("Hello world! 🙂 Take a look at this: z"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x7B,
+			Expected: []byte("Hello world! 🙂 Take a look at this: {"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x7C,
+			Expected: []byte("Hello world! 🙂 Take a look at this: |"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x7D,
+			Expected: []byte("Hello world! 🙂 Take a look at this: }"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x7E,
+			Expected: []byte("Hello world! 🙂 Take a look at this: ~"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x7F,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x7F;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x80,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x80;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x81,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x81;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x82,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x82;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x83,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x83;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x84,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x84;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x85,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x85;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x86,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x86;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x87,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x87;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x88,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x88;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x89,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x89;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x8A,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x8A;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x8B,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x8B;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x8C,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x8C;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x8D,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x8D;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x8E,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x8E;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x8F,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x8F;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x90,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x90;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x91,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x91;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x92,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x92;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x93,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x93;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x94,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x94;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x95,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x95;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x96,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x96;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x97,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x97;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x98,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x98;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x99,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x99;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x9A,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x9A;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x9B,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x9B;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x9C,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x9C;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x9D,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x9D;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x9E,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x9E;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0x9F,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x9F;"),
+		},
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			Rune: 0xA0,
+			Expected: []byte("Hello world! 🙂 Take a look at this: \u00A0"),
+		},
+	}
+
+	for testNumber, test := range tests {
+
+		var p []byte = append([]byte(nil), test.Bytes...)
+		actual := htmlescape.AppendRune(p, test.Rune)
+
+		expected := test.Expected
+
+		if !bytes.Equal(expected, actual) {
+			t.Errorf("For test #%d, the actual resulting value of the append is not what was expected.", testNumber)
+			t.Logf("EXPECTED: %q", expected)
+			t.Logf("ACTUAL:   %q", actual)
+			t.Logf("RUNE: %q (%U)", test.Rune, test.Rune)
+			t.Logf("BYTES: %q", test.Bytes)
+			continue
+		}
+	}
+}
diff --git a/appendstring_test.go b/appendstring_test.go
new file mode 100644
index 0000000..2b32cd9
--- /dev/null
+++ b/appendstring_test.go
@@ -0,0 +1,65 @@
+package htmlescape_test
+
+import (
+	"testing"
+
+	"bytes"
+
+	"sourcecode.social/reiver/go-htmlescape"
+)
+
+func TestAppendString(t *testing.T) {
+
+	tests := []struct{
+		Bytes []byte
+		String string
+		Expected []byte
+	}{
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			String:                                               "This is NOT <b>bold</b>!",
+			Expected: []byte("Hello world! 🙂 Take a look at this: This is NOT &lt;b&gt;bold&lt;/b&gt;!"),
+		},
+
+
+
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			String:                                               `"this is a quotation"`,
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#34;this is a quotation&#34;"),
+		},
+
+
+
+		{
+			Bytes:    []byte("Hello world! 🙂 Take a look at this: "),
+			String:                                                  "\t3 < 5\r\n3 > 2\x00",
+			Expected: []byte("Hello world! 🙂 Take a look at this: &#x9;3 &lt; 5&#xD;&#xA;3 &gt; 2&#x0;"),
+		},
+	}
+
+	for testNumber, test := range tests {
+
+		var p []byte = append([]byte(nil), test.Bytes...)
+		actual, err := htmlescape.AppendString(p, test.String)
+
+		if nil != err {
+			t.Errorf("For test #%d, did not expect to get an error but actually got one." , testNumber)
+			t.Logf("ERROR: (%T) %s", err, err)
+			t.Logf("STRING: %q", test.String)
+			t.Logf("BYTES: %q", test.Bytes)
+			continue
+		}
+
+		expected := test.Expected
+
+		if !bytes.Equal(expected, actual) {
+			t.Errorf("For test #%d, the actual resulting value of the append is not what was expected.", testNumber)
+			t.Logf("EXPECTED: %q", expected)
+			t.Logf("ACTUAL:   %q", actual)
+			t.Logf("STRING: %q", test.String)
+			t.Logf("BYTES: %q", test.Bytes)
+			continue
+		}
+	}
+}