1package retry
  2
  3import (
  4	"context"
  5	"errors"
  6	"testing"
  7	"time"
  8)
  9
 10func TestDo_Success(t *testing.T) {
 11	cfg := Config{
 12		MaxAttempts: 3,
 13		BaseDelay:   time.Millisecond,
 14		MaxDelay:    10 * time.Millisecond,
 15		Multiplier:  2.0,
 16	}
 17
 18	calls := 0
 19	err := Do(context.Background(), cfg, func() error {
 20		calls++
 21		return nil
 22	})
 23
 24	if err != nil {
 25		t.Errorf("expected nil error, got %v", err)
 26	}
 27	if calls != 1 {
 28		t.Errorf("expected 1 call, got %d", calls)
 29	}
 30}
 31
 32func TestDo_RetryThenSuccess(t *testing.T) {
 33	cfg := Config{
 34		MaxAttempts: 3,
 35		BaseDelay:   time.Millisecond,
 36		MaxDelay:    10 * time.Millisecond,
 37		Multiplier:  2.0,
 38	}
 39
 40	calls := 0
 41	err := Do(context.Background(), cfg, func() error {
 42		calls++
 43		if calls < 3 {
 44			return errors.New("temporary error")
 45		}
 46		return nil
 47	})
 48
 49	if err != nil {
 50		t.Errorf("expected nil error, got %v", err)
 51	}
 52	if calls != 3 {
 53		t.Errorf("expected 3 calls, got %d", calls)
 54	}
 55}
 56
 57func TestDo_MaxAttemptsExceeded(t *testing.T) {
 58	cfg := Config{
 59		MaxAttempts: 2,
 60		BaseDelay:   time.Millisecond,
 61		MaxDelay:    10 * time.Millisecond,
 62		Multiplier:  2.0,
 63	}
 64
 65	testErr := errors.New("persistent error")
 66	calls := 0
 67	err := Do(context.Background(), cfg, func() error {
 68		calls++
 69		return testErr
 70	})
 71
 72	if err == nil {
 73		t.Error("expected error, got nil")
 74	}
 75	if !errors.Is(err, ErrMaxAttemptsExceeded) {
 76		t.Errorf("expected ErrMaxAttemptsExceeded, got %v", err)
 77	}
 78	if !errors.Is(err, testErr) {
 79		t.Errorf("expected wrapped testErr, got %v", err)
 80	}
 81	if calls != 2 {
 82		t.Errorf("expected 2 calls, got %d", calls)
 83	}
 84}
 85
 86func TestDo_ContextCancellation(t *testing.T) {
 87	cfg := Config{
 88		MaxAttempts: 10,
 89		BaseDelay:   100 * time.Millisecond,
 90		MaxDelay:    time.Second,
 91		Multiplier:  2.0,
 92	}
 93
 94	ctx, cancel := context.WithCancel(context.Background())
 95	calls := 0
 96
 97	go func() {
 98		time.Sleep(10 * time.Millisecond)
 99		cancel()
100	}()
101
102	err := Do(ctx, cfg, func() error {
103		calls++
104		return errors.New("keep retrying")
105	})
106
107	if !errors.Is(err, context.Canceled) {
108		t.Errorf("expected context.Canceled, got %v", err)
109	}
110}