test: Add tests for retry func

internal/util/retry_test.go

@@ -0,0 +1,89 @@
+package util
+
+import (
+	"context"
+	"errors"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRetry(t *testing.T) {
+	t.Run("halt", func(t *testing.T) {
+		targetErr := errors.New("test")
+		var runs int
+		if err := Retry(context.Background(), 10, 0, func(try uint) error {
+			runs += 1
+			return HaltRetries(targetErr)
+		}); !assert.ErrorIs(t, targetErr, err) {
+			return
+		}
+		assert.Equal(t, 1, runs)
+	})
+
+	t.Run("max", func(t *testing.T) {
+		var runs int
+		if err := Retry(context.Background(), 10, 0, func(try uint) error {
+			runs += 1
+			return errors.New("test")
+		}); !assert.Error(t, err) {
+			return
+		}
+		assert.Equal(t, 10, runs)
+	})
+
+	t.Run("pass on first run", func(t *testing.T) {
+		var runs int
+		if err := Retry(context.Background(), 10, 0, func(try uint) error {
+			runs += 1
+			return nil
+		}); !assert.NoError(t, err) {
+			return
+		}
+		assert.Equal(t, 1, runs)
+	})
+
+	t.Run("pass on fifth run", func(t *testing.T) {
+		var runs int
+		if err := Retry(context.Background(), 10, 0, func(try uint) error {
+			runs += 1
+			if runs < 5 {
+				return errors.New("test")
+			}
+			return nil
+		}); !assert.NoError(t, err) {
+			return
+		}
+		assert.Equal(t, 5, runs)
+	})
+
+	t.Run("sleep backoff", func(t *testing.T) {
+		var runs int
+		start := time.Now()
+		if err := Retry(context.Background(), 10, time.Millisecond, func(try uint) error {
+			runs += 1
+			if runs < 5 {
+				return errors.New("test")
+			}
+			return nil
+		}); !assert.NoError(t, err) {
+			return
+		}
+		assert.Equal(t, 5, runs)
+		assert.Greater(t, time.Since(start), 15*time.Millisecond)
+	})
+
+	t.Run("cancel context", func(t *testing.T) {
+		var runs int
+		ctx, cancel := context.WithCancel(context.Background())
+		cancel()
+		if err := Retry(ctx, 10, 0, func(try uint) error {
+			runs += 1
+			return errors.New("test")
+		}); !assert.Error(t, err) {
+			return
+		}
+		assert.Equal(t, 1, runs)
+	})
+}