// Copyright 2013 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 main import ( "bufio" "bytes" "cmd/internal/browser" "fmt" "html/template" "io" "math" "os" "path/filepath" "strings" "golang.org/x/tools/cover" ) // htmlOutput reads the profile data from profile and generates an HTML // coverage report, writing it to outfile. If outfile is empty, // it writes the report to a temporary file and opens it in a web browser. func htmlOutput(profile, outfile string) error { profiles, err := cover.ParseProfiles(profile) if err != nil { return err } var d templateData dirs, err := findPkgs(profiles) if err != nil { return err } for _, profile := range profiles { fn := profile.FileName if profile.Mode == "set" { d.Set = true } file, err := findFile(dirs, fn) if err != nil { return err } src, err := os.ReadFile(file) if err != nil { return fmt.Errorf("can't read %q: %v", fn, err) } var buf strings.Builder err = htmlGen(&buf, src, profile.Boundaries(src)) if err != nil { return err } d.Files = append(d.Files, &templateFile{ Name: fn, Body: template.HTML(buf.String()), Coverage: percentCovered(profile), }) } var out *os.File if outfile == "" { var dir string dir, err = os.MkdirTemp("", "cover") if err != nil { return err } out, err = os.Create(filepath.Join(dir, "coverage.html")) } else { out, err = os.Create(outfile) } if err != nil { return err } err = htmlTemplate.Execute(out, d) if err2 := out.Close(); err == nil { err = err2 } if err != nil { return err } if outfile == "" { if !browser.Open("file://" + out.Name()) { fmt.Fprintf(os.Stderr, "HTML output written to %s\n", out.Name()) } } return nil } // percentCovered returns, as a percentage, the fraction of the statements in // the profile covered by the test run. // In effect, it reports the coverage of a given source file. func percentCovered(p *cover.Profile) float64 { var total, covered int64 for _, b := range p.Blocks { total += int64(b.NumStmt) if b.Count > 0 { covered += int64(b.NumStmt) } } if total == 0 { return 0 } return float64(covered) / float64(total) * 100 } // htmlGen generates an HTML coverage report with the provided filename, // source code, and tokens, and writes it to the given Writer. func htmlGen(w io.Writer, src []byte, boundaries []cover.Boundary) error { dst := bufio.NewWriter(w) for i := range src { for len(boundaries) > 0 && boundaries[0].Offset == i { b := boundaries[0] if b.Start { n := 0 if b.Count > 0 { n = int(math.Floor(b.Norm*9)) + 1 } fmt.Fprintf(dst, ``, n, b.Count) } else { dst.WriteString("") } boundaries = boundaries[1:] } switch b := src[i]; b { case '>': dst.WriteString(">") case '<': dst.WriteString("<") case '&': dst.WriteString("&") case '\t': dst.WriteString(" ") default: dst.WriteByte(b) } } return dst.Flush() } // rgb returns an rgb value for the specified coverage value // between 0 (no coverage) and 10 (max coverage). func rgb(n int) string { if n == 0 { return "rgb(192, 0, 0)" // Red } // Gradient from gray to green. r := 128 - 12*(n-1) g := 128 + 12*(n-1) b := 128 + 3*(n-1) return fmt.Sprintf("rgb(%v, %v, %v)", r, g, b) } // colors generates the CSS rules for coverage colors. func colors() template.CSS { var buf bytes.Buffer for i := 0; i < 11; i++ { fmt.Fprintf(&buf, ".cov%v { color: %v }\n", i, rgb(i)) } return template.CSS(buf.String()) } var htmlTemplate = template.Must(template.New("html").Funcs(template.FuncMap{ "colors": colors, }).Parse(tmplHTML)) type templateData struct { Files []*templateFile Set bool } // PackageName returns a name for the package being shown. // It does this by choosing the penultimate element of the path // name, so foo.bar/baz/foo.go chooses 'baz'. This is cheap // and easy, avoids parsing the Go file, and gets a better answer // for package main. It returns the empty string if there is // a problem. func (td templateData) PackageName() string { if len(td.Files) == 0 { return "" } fileName := td.Files[0].Name elems := strings.Split(fileName, "/") // Package path is always slash-separated. // Return the penultimate non-empty element. for i := len(elems) - 2; i >= 0; i-- { if elems[i] != "" { return elems[i] } } return "" } type templateFile struct { Name string Body template.HTML Coverage float64 } const tmplHTML = ` {{$pkg := .PackageName}}{{if $pkg}}{{$pkg}}: {{end}}Go Coverage Report
not tracked {{if .Set}} not covered covered {{else}} no coverage low coverage * * * * * * * * high coverage {{end}}
{{range $i, $f := .Files}} {{end}}
`