Merge branch 'master' into no-preallocation

Author: JaSei

go.mod

@@ -2,4 +2,4 @@ module github.com/avast/retry-go/v4
 
 go 1.13
 
-require github.com/stretchr/testify v1.8.1
+require github.com/stretchr/testify v1.8.2

go.sum

@@ -8,8 +8,8 @@ github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSS
 github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
 github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
-github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
-github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
+github.com/stretchr/testify v1.8.2 h1:+h33VjcLVPDHtOdpUCuF+7gSuG3yGIftsP1YvFihtJ8=
+github.com/stretchr/testify v1.8.2/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

retry.go

@@ -97,12 +97,15 @@ func Do(retryableFunc RetryableFunc, opts ...Option) error {
 	// Setting attempts to 0 means we'll retry until we succeed
 	if config.attempts == 0 {
 		for err := retryableFunc(); err != nil; err = retryableFunc() {
-			n++
-
 			if !IsRecoverable(err) {
 				return err
 			}
 
+			if !config.retryIf(err) {
+				return err
+			}
+
+			n++
 			config.onRetry(n, err)
 			select {
 			case <-config.timer.After(delay(config, n, err)):
@@ -262,8 +265,13 @@ func Unrecoverable(err error) error {
 
 // IsRecoverable checks if error is an instance of `unrecoverableError`
 func IsRecoverable(err error) bool {
+	return !errors.Is(err, unrecoverableError{})
+}
+
+// Adds support for errors.Is usage on unrecoverableError
+func (unrecoverableError) Is(err error) bool {
 	_, isUnrecoverable := err.(unrecoverableError)
-	return !isUnrecoverable
+	return isUnrecoverable
 }
 
 func unpackUnrecoverable(err error) error {

retry_test.go

@@ -72,7 +72,29 @@ func TestRetryIf(t *testing.T) {
 	assert.Len(t, err, 3)
 	assert.Equal(t, expectedErrorFormat, err.Error(), "retry error format")
 	assert.Equal(t, uint(2), retryCount, "right count of retry")
+}
+
+func TestRetryIf_ZeroAttempts(t *testing.T) {
+	var retryCount uint
+	err := Do(
+		func() error {
+			if retryCount >= 2 {
+				return errors.New("special")
+			} else {
+				return errors.New("test")
+			}
+		},
+		OnRetry(func(n uint, err error) { retryCount++ }),
+		RetryIf(func(err error) bool {
+			return err.Error() != "special"
+		}),
+		Delay(time.Nanosecond),
+		Attempts(0),
+	)
+	assert.Error(t, err)
 
+	assert.Equal(t, "special", err.Error(), "retry error format")
+	assert.Equal(t, uint(2), retryCount, "right count of retry")
 }
 
 func TestZeroAttemptsWithError(t *testing.T) {
@@ -504,6 +526,7 @@ func TestUnwrap(t *testing.T) {
 	assert.Equal(t, testError, errors.Unwrap(err))
 }
 
+
 func BenchmarkDo(b *testing.B) {
 	testError := errors.New("test error")
 
@@ -529,3 +552,14 @@ func BenchmarkDoNoErrors(b *testing.B) {
 		)
 	}
 }
+
+func TestIsRecoverable(t *testing.T) {
+	err := errors.New("err")
+	assert.True(t, IsRecoverable(err))
+
+	err = Unrecoverable(err)
+	assert.False(t, IsRecoverable(err))
+
+	err = fmt.Errorf("wrapping: %w", err)
+	assert.False(t, IsRecoverable(err))
+}