feat(cli): add ProgressBar with Increment, Set, SetMessage, Done

Co-Authored-By: Virgil <virgil@lethean.io>

pkg/cli/progressbar.go

@@ -0,0 +1,106 @@
+package cli
+
+import (
+	"fmt"
+	"strings"
+	"sync"
+)
+
+// ProgressHandle controls a progress bar.
+type ProgressHandle struct {
+	mu      sync.Mutex
+	current int
+	total   int
+	message string
+	width   int
+}
+
+// NewProgressBar creates a new progress bar with the given total.
+func NewProgressBar(total int) *ProgressHandle {
+	return &ProgressHandle{
+		total: total,
+		width: 30,
+	}
+}
+
+// Current returns the current progress value.
+func (p *ProgressHandle) Current() int {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	return p.current
+}
+
+// Total returns the total value.
+func (p *ProgressHandle) Total() int {
+	return p.total
+}
+
+// Increment advances the progress by 1.
+func (p *ProgressHandle) Increment() {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	if p.current < p.total {
+		p.current++
+	}
+	p.render()
+}
+
+// Set sets the progress to a specific value.
+func (p *ProgressHandle) Set(n int) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	if n > p.total {
+		n = p.total
+	}
+	if n < 0 {
+		n = 0
+	}
+	p.current = n
+	p.render()
+}
+
+// SetMessage sets the message displayed alongside the bar.
+func (p *ProgressHandle) SetMessage(msg string) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	p.message = msg
+	p.render()
+}
+
+// Done completes the progress bar and moves to a new line.
+func (p *ProgressHandle) Done() {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	p.current = p.total
+	p.render()
+	fmt.Println()
+}
+
+// String returns the rendered progress bar without ANSI cursor control.
+func (p *ProgressHandle) String() string {
+	pct := 0
+	if p.total > 0 {
+		pct = (p.current * 100) / p.total
+	}
+
+	filled := 0
+	if p.total > 0 {
+		filled = (p.width * p.current) / p.total
+	}
+	if filled > p.width {
+		filled = p.width
+	}
+	empty := p.width - filled
+
+	bar := "[" + strings.Repeat("\u2588", filled) + strings.Repeat("\u2591", empty) + "]"
+
+	if p.message != "" {
+		return fmt.Sprintf("%s %3d%% %s", bar, pct, p.message)
+	}
+	return fmt.Sprintf("%s %3d%%", bar, pct)
+}
+
+// render outputs the progress bar, overwriting the current line.
+func (p *ProgressHandle) render() {
+	fmt.Printf("\033[2K\r%s", p.String())
+}

pkg/cli/progressbar_test.go

@@ -0,0 +1,60 @@
+package cli
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestProgressBar_Good_Create(t *testing.T) {
+	pb := NewProgressBar(100)
+	require.NotNil(t, pb)
+	assert.Equal(t, 0, pb.Current())
+	assert.Equal(t, 100, pb.Total())
+}
+
+func TestProgressBar_Good_Increment(t *testing.T) {
+	pb := NewProgressBar(10)
+	pb.Increment()
+	assert.Equal(t, 1, pb.Current())
+	pb.Increment()
+	assert.Equal(t, 2, pb.Current())
+}
+
+func TestProgressBar_Good_SetMessage(t *testing.T) {
+	pb := NewProgressBar(10)
+	pb.SetMessage("Processing file.go")
+	assert.Equal(t, "Processing file.go", pb.message)
+}
+
+func TestProgressBar_Good_Set(t *testing.T) {
+	pb := NewProgressBar(100)
+	pb.Set(50)
+	assert.Equal(t, 50, pb.Current())
+}
+
+func TestProgressBar_Good_Done(t *testing.T) {
+	pb := NewProgressBar(5)
+	for i := 0; i < 5; i++ {
+		pb.Increment()
+	}
+	pb.Done()
+	// After Done, Current == Total
+	assert.Equal(t, 5, pb.Current())
+}
+
+func TestProgressBar_Bad_ExceedsTotal(t *testing.T) {
+	pb := NewProgressBar(2)
+	pb.Increment()
+	pb.Increment()
+	pb.Increment() // Should clamp to total
+	assert.Equal(t, 2, pb.Current())
+}
+
+func TestProgressBar_Good_Render(t *testing.T) {
+	pb := NewProgressBar(10)
+	pb.Set(5)
+	rendered := pb.String()
+	assert.Contains(t, rendered, "50%")
+}