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Source file src/cmd/cover/html.go

     1	// Copyright 2013 The Go Authors. All rights reserved.
     2	// Use of this source code is governed by a BSD-style
     3	// license that can be found in the LICENSE file.
     4	
     5	package main
     6	
     7	import (
     8		"bufio"
     9		"bytes"
    10		"cmd/internal/browser"
    11		"fmt"
    12		"html/template"
    13		"io"
    14		"io/ioutil"
    15		"math"
    16		"os"
    17		"path/filepath"
    18		"strings"
    19	)
    20	
    21	// htmlOutput reads the profile data from profile and generates an HTML
    22	// coverage report, writing it to outfile. If outfile is empty,
    23	// it writes the report to a temporary file and opens it in a web browser.
    24	func htmlOutput(profile, outfile string) error {
    25		profiles, err := ParseProfiles(profile)
    26		if err != nil {
    27			return err
    28		}
    29	
    30		var d templateData
    31	
    32		dirs, err := findPkgs(profiles)
    33		if err != nil {
    34			return err
    35		}
    36	
    37		for _, profile := range profiles {
    38			fn := profile.FileName
    39			if profile.Mode == "set" {
    40				d.Set = true
    41			}
    42			file, err := findFile(dirs, fn)
    43			if err != nil {
    44				return err
    45			}
    46			src, err := ioutil.ReadFile(file)
    47			if err != nil {
    48				return fmt.Errorf("can't read %q: %v", fn, err)
    49			}
    50			var buf strings.Builder
    51			err = htmlGen(&buf, src, profile.Boundaries(src))
    52			if err != nil {
    53				return err
    54			}
    55			d.Files = append(d.Files, &templateFile{
    56				Name:     fn,
    57				Body:     template.HTML(buf.String()),
    58				Coverage: percentCovered(profile),
    59			})
    60		}
    61	
    62		var out *os.File
    63		if outfile == "" {
    64			var dir string
    65			dir, err = ioutil.TempDir("", "cover")
    66			if err != nil {
    67				return err
    68			}
    69			out, err = os.Create(filepath.Join(dir, "coverage.html"))
    70		} else {
    71			out, err = os.Create(outfile)
    72		}
    73		if err != nil {
    74			return err
    75		}
    76		err = htmlTemplate.Execute(out, d)
    77		if err2 := out.Close(); err == nil {
    78			err = err2
    79		}
    80		if err != nil {
    81			return err
    82		}
    83	
    84		if outfile == "" {
    85			if !browser.Open("file://" + out.Name()) {
    86				fmt.Fprintf(os.Stderr, "HTML output written to %s\n", out.Name())
    87			}
    88		}
    89	
    90		return nil
    91	}
    92	
    93	// percentCovered returns, as a percentage, the fraction of the statements in
    94	// the profile covered by the test run.
    95	// In effect, it reports the coverage of a given source file.
    96	func percentCovered(p *Profile) float64 {
    97		var total, covered int64
    98		for _, b := range p.Blocks {
    99			total += int64(b.NumStmt)
   100			if b.Count > 0 {
   101				covered += int64(b.NumStmt)
   102			}
   103		}
   104		if total == 0 {
   105			return 0
   106		}
   107		return float64(covered) / float64(total) * 100
   108	}
   109	
   110	// htmlGen generates an HTML coverage report with the provided filename,
   111	// source code, and tokens, and writes it to the given Writer.
   112	func htmlGen(w io.Writer, src []byte, boundaries []Boundary) error {
   113		dst := bufio.NewWriter(w)
   114		for i := range src {
   115			for len(boundaries) > 0 && boundaries[0].Offset == i {
   116				b := boundaries[0]
   117				if b.Start {
   118					n := 0
   119					if b.Count > 0 {
   120						n = int(math.Floor(b.Norm*9)) + 1
   121					}
   122					fmt.Fprintf(dst, `<span class="cov%v" title="%v">`, n, b.Count)
   123				} else {
   124					dst.WriteString("</span>")
   125				}
   126				boundaries = boundaries[1:]
   127			}
   128			switch b := src[i]; b {
   129			case '>':
   130				dst.WriteString("&gt;")
   131			case '<':
   132				dst.WriteString("&lt;")
   133			case '&':
   134				dst.WriteString("&amp;")
   135			case '\t':
   136				dst.WriteString("        ")
   137			default:
   138				dst.WriteByte(b)
   139			}
   140		}
   141		return dst.Flush()
   142	}
   143	
   144	// rgb returns an rgb value for the specified coverage value
   145	// between 0 (no coverage) and 10 (max coverage).
   146	func rgb(n int) string {
   147		if n == 0 {
   148			return "rgb(192, 0, 0)" // Red
   149		}
   150		// Gradient from gray to green.
   151		r := 128 - 12*(n-1)
   152		g := 128 + 12*(n-1)
   153		b := 128 + 3*(n-1)
   154		return fmt.Sprintf("rgb(%v, %v, %v)", r, g, b)
   155	}
   156	
   157	// colors generates the CSS rules for coverage colors.
   158	func colors() template.CSS {
   159		var buf bytes.Buffer
   160		for i := 0; i < 11; i++ {
   161			fmt.Fprintf(&buf, ".cov%v { color: %v }\n", i, rgb(i))
   162		}
   163		return template.CSS(buf.String())
   164	}
   165	
   166	var htmlTemplate = template.Must(template.New("html").Funcs(template.FuncMap{
   167		"colors": colors,
   168	}).Parse(tmplHTML))
   169	
   170	type templateData struct {
   171		Files []*templateFile
   172		Set   bool
   173	}
   174	
   175	type templateFile struct {
   176		Name     string
   177		Body     template.HTML
   178		Coverage float64
   179	}
   180	
   181	const tmplHTML = `
   182	<!DOCTYPE html>
   183	<html>
   184		<head>
   185			<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
   186			<style>
   187				body {
   188					background: black;
   189					color: rgb(80, 80, 80);
   190				}
   191				body, pre, #legend span {
   192					font-family: Menlo, monospace;
   193					font-weight: bold;
   194				}
   195				#topbar {
   196					background: black;
   197					position: fixed;
   198					top: 0; left: 0; right: 0;
   199					height: 42px;
   200					border-bottom: 1px solid rgb(80, 80, 80);
   201				}
   202				#content {
   203					margin-top: 50px;
   204				}
   205				#nav, #legend {
   206					float: left;
   207					margin-left: 10px;
   208				}
   209				#legend {
   210					margin-top: 12px;
   211				}
   212				#nav {
   213					margin-top: 10px;
   214				}
   215				#legend span {
   216					margin: 0 5px;
   217				}
   218				{{colors}}
   219			</style>
   220		</head>
   221		<body>
   222			<div id="topbar">
   223				<div id="nav">
   224					<select id="files">
   225					{{range $i, $f := .Files}}
   226					<option value="file{{$i}}">{{$f.Name}} ({{printf "%.1f" $f.Coverage}}%)</option>
   227					{{end}}
   228					</select>
   229				</div>
   230				<div id="legend">
   231					<span>not tracked</span>
   232				{{if .Set}}
   233					<span class="cov0">not covered</span>
   234					<span class="cov8">covered</span>
   235				{{else}}
   236					<span class="cov0">no coverage</span>
   237					<span class="cov1">low coverage</span>
   238					<span class="cov2">*</span>
   239					<span class="cov3">*</span>
   240					<span class="cov4">*</span>
   241					<span class="cov5">*</span>
   242					<span class="cov6">*</span>
   243					<span class="cov7">*</span>
   244					<span class="cov8">*</span>
   245					<span class="cov9">*</span>
   246					<span class="cov10">high coverage</span>
   247				{{end}}
   248				</div>
   249			</div>
   250			<div id="content">
   251			{{range $i, $f := .Files}}
   252			<pre class="file" id="file{{$i}}" style="display: none">{{$f.Body}}</pre>
   253			{{end}}
   254			</div>
   255		</body>
   256		<script>
   257		(function() {
   258			var files = document.getElementById('files');
   259			var visible;
   260			files.addEventListener('change', onChange, false);
   261			function select(part) {
   262				if (visible)
   263					visible.style.display = 'none';
   264				visible = document.getElementById(part);
   265				if (!visible)
   266					return;
   267				files.value = part;
   268				visible.style.display = 'block';
   269				location.hash = part;
   270			}
   271			function onChange() {
   272				select(files.value);
   273				window.scrollTo(0, 0);
   274			}
   275			if (location.hash != "") {
   276				select(location.hash.substr(1));
   277			}
   278			if (!visible) {
   279				select("file0");
   280			}
   281		})();
   282		</script>
   283	</html>
   284	`
   285	

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