Implement progressbar for web_connectivity test

internal/log/handlers/cli/cli.go

@@ -7,10 +7,12 @@ import (
 	"strings"
 	"sync"
 	"time"
+	"unicode/utf8"
 
 	"github.com/apex/log"
 	"github.com/fatih/color"
 	colorable "github.com/mattn/go-colorable"
+	"github.com/ooni/probe-cli/internal/log/handlers/cli/progress"
 )
 
 // Default handler outputting to stderr.
@@ -71,14 +73,21 @@ func logSectionTitle(w io.Writer, f log.Fields) error {
 	return nil
 }
 
+var bar *progress.Bar
+var lastBarChars int64
+
 // TypedLog is used for handling special "typed" logs to the CLI
 func (h *Handler) TypedLog(t string, e *log.Entry) error {
 	switch t {
 	case "progress":
-		// XXX replace this with something more fancy like https://github.com/tj/go-progress
+		var err error
-		fmt.Fprintf(h.Writer, "%.1f%% [%s]: %s", e.Fields.Get("percentage").(float64)*100, e.Fields.Get("key"), e.Message)
+		if bar == nil {
-		fmt.Fprintln(h.Writer)
+			bar = progress.New(1.0)
-		return nil
+		}
+		bar.Value(e.Fields.Get("percentage").(float64))
+		bar.Text(e.Message)
+		lastBarChars, err = bar.WriteTo(h.Writer)
+		return err
 	case "result_item":
 		return logResultItem(h.Writer, e.Fields)
 	case "result_summary":
@@ -96,16 +105,28 @@ func (h *Handler) DefaultLog(e *log.Entry) error {
 	level := Strings[e.Level]
 	names := e.Fields.Names()
 
-	color.Fprintf(h.Writer, "%s %-25s", bold.Sprintf("%*s", h.Padding+1, level), e.Message)
+	s := color.Sprintf("%s %-25s", bold.Sprintf("%*s", h.Padding+1, level), e.Message)
-
 	for _, name := range names {
 		if name == "source" {
 			continue
 		}
-		fmt.Fprintf(h.Writer, " %s=%s", color.Sprint(name), e.Fields.Get(name))
+		s += fmt.Sprintf(" %s=%s", color.Sprint(name), e.Fields.Get(name))
 	}
 
+	if bar != nil {
+		// We need to move the cursor back to the begging of the line and add some
+		// padding to the end of the string to delete the previous line written to
+		// the console.
+		sChars := int64(utf8.RuneCountInString(s))
+		fmt.Fprintf(h.Writer,
+			fmt.Sprintf("\r%s%s", s, strings.Repeat(" ", int(lastBarChars-sChars))),
+		)
 		fmt.Fprintln(h.Writer)
+		bar.WriteTo(h.Writer)
+	} else {
+		fmt.Fprintf(h.Writer, s)
+		fmt.Fprintln(h.Writer)
+	}
 
 	return nil
 }

internal/log/handlers/cli/progress/progress.go

@@ -0,0 +1,126 @@
+// Package progress provides a simple terminal progress bar.
+package progress
+
+import (
+	"bytes"
+	"fmt"
+	"html/template"
+	"io"
+	"math"
+	"strings"
+)
+
+// Bar is a progress bar.
+type Bar struct {
+	StartDelimiter string  // StartDelimiter for the bar ("|").
+	EndDelimiter   string  // EndDelimiter for the bar ("|").
+	Filled         string  // Filled section representation ("█").
+	Empty          string  // Empty section representation ("░")
+	Total          float64 // Total value.
+	Width          int     // Width of the bar.
+
+	value float64
+	tmpl  *template.Template
+	text  string
+}
+
+// New returns a new bar with the given total.
+func New(total float64) *Bar {
+	b := &Bar{
+		StartDelimiter: "|",
+		EndDelimiter:   "|",
+		Filled:         "█",
+		Empty:          "░",
+		Total:          total,
+		Width:          60,
+	}
+
+	b.Template(`{{.Percent | printf "%3.0f"}}% {{.Bar}} {{.Text}}`)
+
+	return b
+}
+
+// NewInt returns a new bar with the given total.
+func NewInt(total int) *Bar {
+	return New(float64(total))
+}
+
+// Text sets the text value.
+func (b *Bar) Text(s string) {
+	b.text = s
+}
+
+// Value sets the value.
+func (b *Bar) Value(n float64) {
+	if n > b.Total {
+		panic("Bar update value cannot be greater than the total")
+	}
+	b.value = n
+}
+
+// ValueInt sets the value.
+func (b *Bar) ValueInt(n int) {
+	b.Value(float64(n))
+}
+
+// Percent returns the percentage
+func (b *Bar) percent() float64 {
+	return (b.value / b.Total) * 100
+}
+
+// Bar returns the progress bar string.
+func (b *Bar) bar() string {
+	p := b.value / b.Total
+	filled := math.Ceil(float64(b.Width) * p)
+	empty := math.Floor(float64(b.Width) - filled)
+	s := b.StartDelimiter
+	s += strings.Repeat(b.Filled, int(filled))
+	s += strings.Repeat(b.Empty, int(empty))
+	s += b.EndDelimiter
+	return s
+}
+
+// String returns the progress bar.
+func (b *Bar) String() string {
+	var buf bytes.Buffer
+
+	data := struct {
+		Value          float64
+		Total          float64
+		Percent        float64
+		StartDelimiter string
+		EndDelimiter   string
+		Bar            string
+		Text           string
+	}{
+		Value:          b.value,
+		Text:           b.text,
+		StartDelimiter: b.StartDelimiter,
+		EndDelimiter:   b.EndDelimiter,
+		Percent:        b.percent(),
+		Bar:            b.bar(),
+	}
+
+	if err := b.tmpl.Execute(&buf, data); err != nil {
+		panic(err)
+	}
+
+	return buf.String()
+}
+
+// WriteTo writes the progress bar to w.
+func (b *Bar) WriteTo(w io.Writer) (int64, error) {
+	s := fmt.Sprintf("\r   %s ", b.String())
+	_, err := io.WriteString(w, s)
+	return int64(len(s)), err
+}
+
+// Template for rendering. This method will panic if the template fails to parse.
+func (b *Bar) Template(s string) {
+	t, err := template.New("").Parse(s)
+	if err != nil {
+		panic(err)
+	}
+
+	b.tmpl = t
+}