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: typesniffer_test.go
    path of file: ./repos/gitea/modules/typesniffer
    
    the code of the file until where you have to start completion: // Copyright 2021 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package typesniffer

import (
	"bytes"
	"encoding/base64"
	"encoding/hex"
	"strings"
	"testing"

	"github.com/stretchr/testify/assert"
)

func TestDetectContentTypeLongerThanSniffLen(t *testing.T) {
	// Pre-condition: Shorter than sniffLen detects SVG.
	assert.Equal(t, "image/svg+xml", DetectContentType([]byte(`<!-- Comment --><svg></svg>`)).contentType)
	// Longer than sniffLen detects something else.
	assert.NotEqual(t, "image/svg+xml", DetectContentType([]byte(`<!-- `+strings.Repeat("x", sniffLen)+` --><svg></svg>`)).contentType)
}

func TestIsTextFile(t *testing.T) {
	assert.True(t, DetectContentType([]byte{}).IsText())
	assert.True(t, DetectContentType([]byte("lorem ipsum")).IsText())
}

func TestIsSvgImage(t *testing.T) {
	assert.True(t, DetectContentType([]byte("<svg></svg>")).IsSvgImage())
	assert.True(t, DetectContentType([]byte("    <svg></svg>")).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<svg width="100"></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<?xml version="1.0" encoding="UTF-8"?><svg></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<!-- Comment -->
	<svg></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<!-- Multiple -->
	<!-- Comments -->
	<svg></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<!-- Multiline
	Comment -->
	<svg></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1 Basic//EN"
	"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11-basic.dtd">
	<svg></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<?xml version="1.0" encoding="UTF-8"?>
	<!-- Comment -->
	<svg></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<?xml version="1.0" encoding="UTF-8"?>
	<!-- Multiple -->
	<!-- Comments -->
	<svg></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<?xml version="1.0" encoding="UTF-8"?>
	<!-- Multline
	Comment -->
	<svg></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<?xml version="1.0" encoding="UTF-8"?>
	<!DOCTYPE sv
    
func TestIsSvgImage(t *testing.T) {
	assert.True(t, DetectContentType([]byte("<svg></svg>")).IsSvgImage())
	assert.True(t, DetectContentType([]byte("    <svg></svg>")).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<svg width="100"></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<?xml version="1.0" encoding="UTF-8"?><svg></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<!-- Comment -->
	<svg></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<!-- Multiple -->
	<!-- Comments -->
	<svg></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<!-- Multiline
	Comment -->
	<svg></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1 Basic//EN"
	"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11-basic.dtd">
	<svg></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<?xml version="1.0" encoding="UTF-8"?>
	<!-- Comment -->
	<svg></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<?xml version="1.0" encoding="UTF-8"?>
	<!-- Multiple -->
	<!-- Comments -->
	<svg></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<?xml version="1.0" encoding="UTF-8"?>
	<!-- Multline
	Comment -->
	<svg></svg>`)).IsSvgImage())
	assert.True(t, DetectContentType([]byte(`<?xml version="1.0" encoding="UTF-8"?>
	<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
	<!-- Multline
	Comment -->
	<svg></svg>`)).IsSvgImage())

	// the DetectContentType should work for incomplete data, because only beginning bytes are used for detection
	assert.True(t, DetectContentType([]byte(`<svg>....`)).IsSvgImage())

	assert.False(t, DetectContentType([]byte{}).IsSvgImage())
	assert.False(t, DetectContentType([]byte("svg")).IsSvgImage())
	assert.False(t, DetectContentType([]byte("<svgfoo></svgfoo>")).IsSvgImage())
	assert.False(t, DetectContentType([]byte("text<svg></svg>")).IsSvgImage())
	assert.False(t, DetectContentType([]byte("<html><body><svg></svg></body></html>")).IsSvgImage())
	assert.False(t, DetectContentType([]byte(`<script>"<svg></svg>"</script>`)).IsSvgImage())
	assert.False(t, DetectContentType([]byte(`<!-- <svg></svg> inside comment -->
	<foo></foo>`)).IsSvgImage())
	assert.False(t, DetectContentType([]byte(`<?xml version="1.0" encoding="UTF-8"?>
	<!-- <svg></svg> inside comment -->
	<foo></foo>`)).IsSvgImage())

	assert.False(t, DetectContentType([]byte(`
<!-- comment1 -->
<div>
	<!-- comment2 -->
	<svg></svg>
</div>
`)).IsSvgImage())

	assert.False(t, DetectContentType([]byte(`
<!-- comment1
-->
<div>
	<!-- comment2
-->
	<svg></svg>
</div>
`)).IsSvgImage())
	assert.False(t, DetectContentType([]byte(`<html><body><!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd"><svg></svg></body></html>`)).IsSvgImage())
	assert.False(t, DetectContentType([]byte(`<html><body><?xml version="1.0" encoding="UTF-8"?><svg></svg></body></html>`)).IsSvgImage())
}