You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: unicode_test.go
    path of file: ./repos/go-starter-kit/vendor/golang.org/x/text/encoding/unicode
    
    the code of the file until where you have to start completion: // Copyright 2015 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 unicode

import (
	"testing"

	"golang.org/x/text/transform"
)

func TestUTF8Decoder(t *testing.T) {
	testCases := []struct {
		desc    string
		src     string
		notEOF  bool // the inverse of atEOF
		sizeDst int
		want    string
		nSrc    int
		err     error
	}{{
		desc: "empty string, empty dest buffer",
	}, {
		desc:    "empty string",
		sizeDst: 8,
	}, {
		desc:    "empty string, streaming",
		notEOF:  true,
		sizeDst: 8,
	}, {
		desc:    "ascii",
		src:     "abcde",
		sizeDst: 8,
		want:    "abcde",
		nSrc:    5,
	}, {
		desc:    "ascii and error",
		src:     "ab\x80de",
		sizeDst: 7,
		want:    "ab\ufffdde",
		nSrc:    5,
	}, {
		desc:    "valid two-byte sequence",
		src:     "a\u0300bc",
		sizeDst: 7,
		want:    "a\u0300bc",
		nSrc:    5,
	}, {
		desc:    "valid three-byte sequence",
		src:     "a\u0300中",
		sizeDst: 7,
		want:    "a\u0300中",
		nSrc:    6,
	}, {
		desc:    "valid four-byte sequence",
		src:     "a中\U00016F50",
		sizeDst: 8,
		want:    "a中\U00016F50",
		nSrc:    8,
	}, {
		desc:    "short source buffer",
		src:     "abc\xf0\x90",
		notEOF:  true,
		sizeDst: 10,
		want:    "abc",
		nSrc:    3,
		err:     transform.ErrShortSrc,
	}, {
		// We don't check for the maximal subpart of an ill-formed subsequence
		// at the end of an open segment.
		desc:    "complete invalid that looks like short at end",
		src:     "abc\xf0\x80",
		notEOF:  true,
		sizeDst: 10,
		want:    "abc", // instead of "abc\ufffd\ufffd",
		nSrc:    3,
		err:     transform.ErrShortSrc,
	}, {
		desc:    "incomplete sequence at end",
		src:     "a\x80bc\xf0\x90",
		sizeDst: 9,
		want:    "a\ufffdbc\ufffd",
		nSrc:    6,
	}, {
		desc:    "invalid second byte",
		src:     "abc\xf0dddd",
		sizeDst: 10,
		want:    "abc\ufffddddd",
		nSrc:    8,
	}, {
		desc:    "invalid second byte at end",
		src:     "abc\xf0d",
		sizeDst: 10,
		want:    "abc\ufffdd",
		nSrc:    5,
	}, {
		desc:    "invalid third byte",
		src:     "a\u0300bc\xf0\x90dddd",
		sizeDst: 12,
		want:    "a\u0300bc\ufffddddd",
		nSrc:    11,
	}, {
		desc:    "invalid third byte at end",
		src:     "a\u0300bc\xf0\x90d",
		sizeDst: 12,
		want:    "a\u0300bc\ufffdd",
		nSrc:    8,
	}, {
		desc:    "invalid fourth byte, tight buffer",
		src:     "a\u0300bc\xf0\x90\x80d",
		sizeDst: 9,
		want:    "a\u0300bc\ufffdd",
		nSrc:    9,
	}, {
		desc:    "invalid fourth byte at end",
		src:     "a\u0300bc\xf0\x90\x80",
		sizeDst: 8,
		want:    "a\u0300bc\ufffd",
		nSrc:    8,
	}, {
		desc:    "invalid fourth byte and short four byte sequence",
		src:     "a\u0300bc\xf0\x90\x80\xf0\x90\x80",
		not
    
func TestUTF8Decoder(t *testing.T) {
	testCases := []struct {
		desc    string
		src     string
		notEOF  bool // the inverse of atEOF
		sizeDst int
		want    string
		nSrc    int
		err     error
	}{{
		desc: "empty string, empty dest buffer",
	}, {
		desc:    "empty string",
		sizeDst: 8,
	}, {
		desc:    "empty string, streaming",
		notEOF:  true,
		sizeDst: 8,
	}, {
		desc:    "ascii",
		src:     "abcde",
		sizeDst: 8,
		want:    "abcde",
		nSrc:    5,
	}, {
		desc:    "ascii and error",
		src:     "ab\x80de",
		sizeDst: 7,
		want:    "ab\ufffdde",
		nSrc:    5,
	}, {
		desc:    "valid two-byte sequence",
		src:     "a\u0300bc",
		sizeDst: 7,
		want:    "a\u0300bc",
		nSrc:    5,
	}, {
		desc:    "valid three-byte sequence",
		src:     "a\u0300中",
		sizeDst: 7,
		want:    "a\u0300中",
		nSrc:    6,
	}, {
		desc:    "valid four-byte sequence",
		src:     "a中\U00016F50",
		sizeDst: 8,
		want:    "a中\U00016F50",
		nSrc:    8,
	}, {
		desc:    "short source buffer",
		src:     "abc\xf0\x90",
		notEOF:  true,
		sizeDst: 10,
		want:    "abc",
		nSrc:    3,
		err:     transform.ErrShortSrc,
	}, {
		// We don't check for the maximal subpart of an ill-formed subsequence
		// at the end of an open segment.
		desc:    "complete invalid that looks like short at end",
		src:     "abc\xf0\x80",
		notEOF:  true,
		sizeDst: 10,
		want:    "abc", // instead of "abc\ufffd\ufffd",
		nSrc:    3,
		err:     transform.ErrShortSrc,
	}, {
		desc:    "incomplete sequence at end",
		src:     "a\x80bc\xf0\x90",
		sizeDst: 9,
		want:    "a\ufffdbc\ufffd",
		nSrc:    6,
	}, {
		desc:    "invalid second byte",
		src:     "abc\xf0dddd",
		sizeDst: 10,
		want:    "abc\ufffddddd",
		nSrc:    8,
	}, {
		desc:    "invalid second byte at end",
		src:     "abc\xf0d",
		sizeDst: 10,
		want:    "abc\ufffdd",
		nSrc:    5,
	}, {
		desc:    "invalid third byte",
		src:     "a\u0300bc\xf0\x90dddd",
		sizeDst: 12,
		want:    "a\u0300bc\ufffddddd",
		nSrc:    11,
	}, {
		desc:    "invalid third byte at end",
		src:     "a\u0300bc\xf0\x90d",
		sizeDst: 12,
		want:    "a\u0300bc\ufffdd",
		nSrc:    8,
	}, {
		desc:    "invalid fourth byte, tight buffer",
		src:     "a\u0300bc\xf0\x90\x80d",
		sizeDst: 9,
		want:    "a\u0300bc\ufffdd",
		nSrc:    9,
	}, {
		desc:    "invalid fourth byte at end",
		src:     "a\u0300bc\xf0\x90\x80",
		sizeDst: 8,
		want:    "a\u0300bc\ufffd",
		nSrc:    8,
	}, {
		desc:    "invalid fourth byte and short four byte sequence",
		src:     "a\u0300bc\xf0\x90\x80\xf0\x90\x80",
		notEOF:  true,
		sizeDst: 20,
		want:    "a\u0300bc\ufffd",
		nSrc:    8,
		err:     transform.ErrShortSrc,
	}, {
		desc:    "valid four-byte sequence overflowing short buffer",
		src:     "a\u0300bc\xf0\x90\x80\x80",
		notEOF:  true,
		sizeDst: 8,
		want:    "a\u0300bc",
		nSrc:    5,
		err:     transform.ErrShortDst,
	}, {
		desc:    "invalid fourth byte at end short, but short dst",
		src:     "a\u0300bc\xf0\x90\x80\xf0\x90\x80",
		notEOF:  true,
		sizeDst: 8,
		// More bytes would fit in the buffer, but this seems to require a more
		// complicated and slower algorithm.
		want: "a\u0300bc", // instead of "a\u0300bc"
		nSrc: 5,
		err:  transform.ErrShortDst,
	}, {
		desc:    "short dst for error",
		src:     "abc\x80",
		notEOF:  true,
		sizeDst: 5,
		want:    "abc",
		nSrc:    3,
		err:     transform.ErrShortDst,
	}, {
		desc:    "adjusting short dst buffer",
		src:     "abc\x80ef",
		notEOF:  true,
		sizeDst: 6,
		want:    "abc\ufffd",
		nSrc:    4,
		err:     transform.ErrShortDst,
	}}
	tr := UTF8.NewDecoder()
	for i, tc := range testCases {
		b := make([]byte, tc.sizeDst)
		nDst, nSrc, err := tr.Transform(b, []byte(tc.src), !tc.notEOF)
		if err != tc.err {
			t.Errorf("%d:%s: error was %v; want %v", i, tc.desc, err, tc.err)
		}
		if got := string(b[:nDst]); got != tc.want {
			t.Errorf("%d:%s: result was %q: want %q", i, tc.desc, got, tc.want)
		}
		if nSrc != tc.nSrc {
			t.Errorf("%d:%s: nSrc was %d; want %d", i, tc.desc, nSrc, tc.nSrc)
		}
	}
}