chore: import upstream snapshot with attribution

client/retry.go

@@ -0,0 +1,36 @@
+package client
+
+import (
+	"context"
+
+	"go-micro.dev/v6/errors"
+)
+
+// note that returning either false or a non-nil error will result in the call not being retried.
+type RetryFunc func(ctx context.Context, req Request, retryCount int, err error) (bool, error)
+
+// RetryAlways always retry on error.
+func RetryAlways(ctx context.Context, req Request, retryCount int, err error) (bool, error) {
+	return true, nil
+}
+
+// RetryOnError retries a request on a 500 or timeout error.
+func RetryOnError(ctx context.Context, req Request, retryCount int, err error) (bool, error) {
+	if err == nil {
+		return false, nil
+	}
+
+	e := errors.Parse(err.Error())
+	if e == nil {
+		return false, nil
+	}
+
+	switch e.Code {
+	// Retry on timeout, not on 500 internal server error, as that is a business
+	// logic error that should be handled by the user.
+	case 408:
+		return true, nil
+	default:
+		return false, nil
+	}
+}