Handle undecodable responses gracefully

Introduced a try-catch block in the data() method to catch
`NotDecodableException` when attempting to decode response data. In such
cases, decoding will now default to an empty array instead of throwing
an unhandled exception. Moreover, clarified method return types in doc
comments for `onError`, `throw`, and `throwIf` to reflect the generic
`Response<T>` type.

src/Response.php

@@ -8,6 +8,7 @@
 use Fansipan\Contracts\DecoderInterface;
 use Fansipan\Contracts\MapperInterface;
 use Fansipan\Exception\HttpException;
+use Fansipan\Exception\NotDecodableException;
 use LogicException;
 use Psr\Http\Message\ResponseInterface;
 
@@ -57,7 +58,11 @@ public function body(): string
     public function data(): array
     {
         if (! $this->decoded) {
-            $this->decoded = Util::iteratorToArray($this->decode());
+            try {
+                $this->decoded = Util::iteratorToArray($this->decode());
+            } catch (NotDecodableException $e) {
+                $this->decoded = [];
+            }
         }
 
         return $this->decoded;
@@ -80,12 +85,12 @@ public function object(): ?object
     /**
      * Get the decoded body the response.
      *
-     * @throws \Fansipan\Exception\NotDecodableException
+     * @throws NotDecodableException
      */
     public function decode(): iterable
     {
         if (! $this->decoder instanceof DecoderInterface) {
-            return [];
+            throw NotDecodableException::create();
         }
 
         return $this->decoder->decode($this->response);
@@ -191,6 +196,8 @@ public function serverError(): bool
 
     /**
      * Execute the given callback if there was a server or client error.
+     *
+     * @return Response<T>
      */
     public function onError(callable $callback): self
     {
@@ -228,6 +235,8 @@ public function toException(): ?HttpException
     /**
      * Throw an exception if a server or client error occurred.
      *
+     * @return Response<T>
+     *
      * @throws \Fansipan\Exception\HttpException
      */
     public function throw(): self
@@ -255,6 +264,7 @@ public function throw(): self
      * Throw an exception if a server or client error occurred and the given condition evaluates to true.
      *
      * @param  \Closure|bool  $condition
+     * @return Response<T>
      *
      * @throws \Fansipan\Exception\HttpException
      */