From cd8a42c2c1dcb58e175477a87dbced9ae127a697 Mon Sep 17 00:00:00 2001
From: parsilver <magician_canobi@hotmail.com>
Date: Mon, 2 Mar 2026 11:58:50 +0700
Subject: [PATCH 1/7] Upgrade farzai/transport to v2.1
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- Update farzai/transport dependency from ^1.2 to ^2.1
- Migrate ClientBuilder to use new TransportBuilder API (withBaseUri, setLogger)
- Replace Request class with RequestBuilder in PendingRequest
- Remove PsrResponseTrait usage and implement PSR-7 delegation directly in AbstractResponseDecorator
- Add jsonOrNull() and toArray() methods to AbstractResponseDecorator
- Fix typo: isSuccessfull() → isSuccessful()
- Fix throw() return type to static for proper chaining
- Add guzzlehttp/guzzle as dev dependency
- Add .phpunit.cache to .gitignore
---
 .gitignore                                    |   1 +
 composer.json                                 |   3 +-
 src/ClientBuilder.php                         |  10 +-
 src/Requests/PendingRequest.php               |  20 +--
 src/Responses/AbstractResponseDecorator.php   | 116 ++++++++++++++++--
 .../ResponseWithValidateErrorCode.php         |  11 +-
 tests/ResponseErrorCodeTest.php               |   2 +-
 7 files changed, 132 insertions(+), 31 deletions(-)

diff --git a/.gitignore b/.gitignore
index 00403f7..b32743b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,6 +3,7 @@
 /.fleet
 .php_cs
 .php_cs.cache
+.phpunit.cache
 .phpunit.result.cache
 build
 composer.lock
diff --git a/composer.json b/composer.json
index c376929..808f7f8 100644
--- a/composer.json
+++ b/composer.json
@@ -16,10 +16,11 @@
     "require": {
         "php": "^8.1",
         "farzai/support": "^1.2",
-        "farzai/transport": "^1.2",
+        "farzai/transport": "^2.1",
         "phrity/websocket": "^3.0"
     },
     "require-dev": {
+        "guzzlehttp/guzzle": "^7.8",
         "pestphp/pest": "^2.15",
         "laravel/pint": "^1.0",
         "spatie/ray": "^1.28"
diff --git a/src/ClientBuilder.php b/src/ClientBuilder.php
index 7372c8e..a6ff4ba 100644
--- a/src/ClientBuilder.php
+++ b/src/ClientBuilder.php
@@ -100,15 +100,15 @@ public function build()
 
         $logger = $this->logger ?? new NullLogger();
 
-        $builder = TransportBuilder::make();
+        $builder = TransportBuilder::make()
+            ->withBaseUri(sprintf('https://%s', self::DEFAULT_HOST))
+            ->setLogger($logger);
+
         if ($this->httpClient) {
-            $builder->setClient($this->httpClient);
+            $builder = $builder->setClient($this->httpClient);
         }
 
-        $builder->setLogger($logger);
-
         $transport = $builder->build();
-        $transport->setUri(sprintf('https://%s', self::DEFAULT_HOST));
 
         $client = new Client(
             config: $this->config,
diff --git a/src/Requests/PendingRequest.php b/src/Requests/PendingRequest.php
index ac2f055..dfdfcfe 100644
--- a/src/Requests/PendingRequest.php
+++ b/src/Requests/PendingRequest.php
@@ -6,7 +6,7 @@
 use Farzai\Bitkub\Contracts\RequestInterceptor;
 use Farzai\Bitkub\Responses\ResponseWithValidateErrorCode;
 use Farzai\Transport\Contracts\ResponseInterface;
-use Farzai\Transport\Request;
+use Farzai\Transport\RequestBuilder;
 use Farzai\Transport\Response;
 use Psr\Http\Message\RequestInterface as PsrRequestInterface;
 use Psr\Http\Message\ResponseInterface as PsrResponseInterface;
@@ -146,25 +146,27 @@ public function createRequest(string $method, string $path, array $options = [])
         // Normalize path
         $path = '/'.trim($path, '/');
 
+        $builder = (new RequestBuilder)->method($method)->uri($path);
+
         // Query
         if (isset($options['query']) && is_array($options['query']) && ! empty($options['query'])) {
-            $path .= '?'.http_build_query($options['query']);
+            $builder = $builder->withQuery($options['query']);
         }
 
         // Set body
         if (isset($options['body'])) {
             $body = $options['body'];
-
-            // Convert array to json
-            if (is_array($body)) {
-                $body = json_encode($body);
-            }
+            $builder = is_array($body)
+                ? $builder->withJson($body)
+                : $builder->withBody($body);
         }
 
         // Set headers
-        $headers = $options['headers'] ?? [];
+        if (! empty($options['headers'])) {
+            $builder = $builder->withHeaders($options['headers']);
+        }
 
-        return new Request($method, $path, $headers, $body ?? null);
+        return $builder->build();
     }
 
     /**
diff --git a/src/Responses/AbstractResponseDecorator.php b/src/Responses/AbstractResponseDecorator.php
index e9a86a5..5b0be0e 100644
--- a/src/Responses/AbstractResponseDecorator.php
+++ b/src/Responses/AbstractResponseDecorator.php
@@ -3,13 +3,11 @@
 namespace Farzai\Bitkub\Responses;
 
 use Farzai\Transport\Contracts\ResponseInterface;
-use Farzai\Transport\Traits\PsrResponseTrait;
 use Psr\Http\Message\RequestInterface as PsrRequestInterface;
+use Psr\Http\Message\StreamInterface;
 
 abstract class AbstractResponseDecorator implements ResponseInterface
 {
-    use PsrResponseTrait;
-
     protected ResponseInterface $response;
 
     /**
@@ -45,11 +43,11 @@ public function headers(): array
     }
 
     /**
-     * Check if the response is successfull.
+     * Check if the response is successful.
      */
-    public function isSuccessfull(): bool
+    public function isSuccessful(): bool
     {
-        return $this->response->isSuccessfull();
+        return $this->response->isSuccessful();
     }
 
     /**
@@ -61,15 +59,31 @@ public function json(?string $key = null): mixed
     }
 
     /**
-     * Throw an exception if the response is not successfull.
-     *
-     * @param  callable<\Farzai\Transport\Contracts\ResponseInterface>  $callback Custom callback to throw an exception.
+     * Return the json decoded response or null.
+     */
+    public function jsonOrNull(?string $key = null): mixed
+    {
+        return $this->response->jsonOrNull($key);
+    }
+
+    /**
+     * Return the response as an array.
+     */
+    public function toArray(): array
+    {
+        return $this->response->toArray();
+    }
+
+    /**
+     * Throw an exception if the response is not successful.
      *
      * @throws \Psr\Http\Client\ClientExceptionInterface
      */
-    public function throw(?callable $callback = null)
+    public function throw(?callable $callback = null): static
     {
-        return $this->response->throw($callback);
+        $this->response->throw($callback);
+
+        return $this;
     }
 
     /**
@@ -79,4 +93,84 @@ public function getPsrRequest(): PsrRequestInterface
     {
         return $this->response->getPsrRequest();
     }
+
+    // PSR-7 ResponseInterface delegation
+
+    public function getStatusCode(): int
+    {
+        return $this->response->getStatusCode();
+    }
+
+    public function withStatus(int $code, string $reasonPhrase = ''): static
+    {
+        return $this->cloneWithResponse($this->response->withStatus($code, $reasonPhrase));
+    }
+
+    public function getReasonPhrase(): string
+    {
+        return $this->response->getReasonPhrase();
+    }
+
+    public function getProtocolVersion(): string
+    {
+        return $this->response->getProtocolVersion();
+    }
+
+    public function withProtocolVersion(string $version): static
+    {
+        return $this->cloneWithResponse($this->response->withProtocolVersion($version));
+    }
+
+    public function getHeaders(): array
+    {
+        return $this->response->getHeaders();
+    }
+
+    public function hasHeader(string $name): bool
+    {
+        return $this->response->hasHeader($name);
+    }
+
+    public function getHeader(string $name): array
+    {
+        return $this->response->getHeader($name);
+    }
+
+    public function getHeaderLine(string $name): string
+    {
+        return $this->response->getHeaderLine($name);
+    }
+
+    public function withHeader(string $name, $value): static
+    {
+        return $this->cloneWithResponse($this->response->withHeader($name, $value));
+    }
+
+    public function withAddedHeader(string $name, $value): static
+    {
+        return $this->cloneWithResponse($this->response->withAddedHeader($name, $value));
+    }
+
+    public function withoutHeader(string $name): static
+    {
+        return $this->cloneWithResponse($this->response->withoutHeader($name));
+    }
+
+    public function getBody(): StreamInterface
+    {
+        return $this->response->getBody();
+    }
+
+    public function withBody(StreamInterface $body): static
+    {
+        return $this->cloneWithResponse($this->response->withBody($body));
+    }
+
+    private function cloneWithResponse(ResponseInterface $response): static
+    {
+        $clone = clone $this;
+        $clone->response = $response;
+
+        return $clone;
+    }
 }
diff --git a/src/Responses/ResponseWithValidateErrorCode.php b/src/Responses/ResponseWithValidateErrorCode.php
index 413ee63..3e5464b 100644
--- a/src/Responses/ResponseWithValidateErrorCode.php
+++ b/src/Responses/ResponseWithValidateErrorCode.php
@@ -8,19 +8,22 @@
 class ResponseWithValidateErrorCode extends AbstractResponseDecorator
 {
     /**
-     * Throw an exception if the response is not successfull.
+     * Throw an exception if the response is not successful.
      *
      *
      * @throws \Psr\Http\Client\ClientExceptionInterface
      */
-    public function throw(?callable $callback = null)
+    public function throw(?callable $callback = null): static
     {
-        return parent::throw($callback ?? function (ResponseInterface $response, ?\Exception $e) use ($callback) {
-            if ($this->json('error') !== null && $this->json('error') !== 0) {
+        parent::throw($callback ?? function (ResponseInterface $response, ?\Exception $e) use ($callback) {
+            $errorCode = $this->json('error');
+            if ($errorCode !== null && $errorCode !== 0) {
                 throw new BitkubResponseErrorCodeException($response);
             }
 
             return $callback ? $callback($response, $e) : $response;
         });
+
+        return $this;
     }
 }
diff --git a/tests/ResponseErrorCodeTest.php b/tests/ResponseErrorCodeTest.php
index 4a78d16..eb961b8 100644
--- a/tests/ResponseErrorCodeTest.php
+++ b/tests/ResponseErrorCodeTest.php
@@ -27,7 +27,7 @@
     expect($response->headers())->toBe([
         'Content-Type' => 'application/json',
     ]);
-    expect($response->isSuccessfull())->toBeTrue();
+    expect($response->isSuccessful())->toBeTrue();
     expect($response->json('error'))->toBe(0);
     expect($response->getPsrRequest())->toBe($psrRequest);
 });

From 63cc15a9aa112cb67ced167adf3e521ceb61db88 Mon Sep 17 00:00:00 2001
From: parsilver <4928451+parsilver@users.noreply.github.com>
Date: Mon, 2 Mar 2026 04:59:16 +0000
Subject: [PATCH 2/7] Fix styling

---
 src/ClientBuilder.php                             | 9 +++------
 src/Endpoints/MarketEndpoint.php                  | 4 ++--
 src/WebSocket/Endpoints/LiveOrderBookEndpoint.php | 2 +-
 src/WebSocket/Engine.php                          | 7 +++----
 4 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/src/ClientBuilder.php b/src/ClientBuilder.php
index a6ff4ba..129970a 100644
--- a/src/ClientBuilder.php
+++ b/src/ClientBuilder.php
@@ -41,7 +41,7 @@ final class ClientBuilder
      */
     public static function create()
     {
-        return new self();
+        return new self;
     }
 
     /**
@@ -98,7 +98,7 @@ public function build()
     {
         $this->ensureConfigIsValid();
 
-        $logger = $this->logger ?? new NullLogger();
+        $logger = $this->logger ?? new NullLogger;
 
         $builder = TransportBuilder::make()
             ->withBaseUri(sprintf('https://%s', self::DEFAULT_HOST))
@@ -130,8 +130,5 @@ private function ensureConfigIsValid(): void
         }
     }
 
-    final public function __construct()
-    {
-
-    }
+    final public function __construct() {}
 }
diff --git a/src/Endpoints/MarketEndpoint.php b/src/Endpoints/MarketEndpoint.php
index 3c6e0ed..6abc414 100644
--- a/src/Endpoints/MarketEndpoint.php
+++ b/src/Endpoints/MarketEndpoint.php
@@ -35,7 +35,7 @@ public function symbols(): ResponseInterface
     /**
      * Get ticker information.
      *
-     * @param  string  $symbol (optional) The symbol (e.g. btc_thb)
+     * @param  string  $symbol  (optional) The symbol (e.g. btc_thb)
      *
      * @response
      * {
@@ -388,7 +388,7 @@ public function balances(): ResponseInterface
      * List all open orders of the given symbol.
      * Note : The client_id of this API response is the input body field name client_id , was inputted by the user of APIs.
      *
-     * @param  string  $sym The symbol (e.g. btc_thb)
+     * @param  string  $sym  The symbol (e.g. btc_thb)
      *
      * @response
      * {
diff --git a/src/WebSocket/Endpoints/LiveOrderBookEndpoint.php b/src/WebSocket/Endpoints/LiveOrderBookEndpoint.php
index ef9ac32..7900050 100644
--- a/src/WebSocket/Endpoints/LiveOrderBookEndpoint.php
+++ b/src/WebSocket/Endpoints/LiveOrderBookEndpoint.php
@@ -13,7 +13,7 @@ class LiveOrderBookEndpoint extends AbstractEndpoint
      *    echo $message->json('sym');
      * });
      *
-     * @param  string|int  $symbol Symbol name or id.
+     * @param  string|int  $symbol  Symbol name or id.
      * @param  callable|array<callable>  $listeners
      */
     public function listen($symbol, $listeners)
diff --git a/src/WebSocket/Engine.php b/src/WebSocket/Engine.php
index 2076d9b..00feec9 100644
--- a/src/WebSocket/Engine.php
+++ b/src/WebSocket/Engine.php
@@ -14,8 +14,7 @@ class Engine implements WebSocketEngineInterface
 {
     public function __construct(
         private LoggerInterface $logger,
-    ) {
-    }
+    ) {}
 
     public function handle(array $listeners): void
     {
@@ -28,8 +27,8 @@ public function handle(array $listeners): void
         $client = new WebSocketClient('wss://api.bitkub.com/websocket-api/'.implode(',', $events));
 
         $client
-            ->addMiddleware(new WebSocketMiddleware\CloseHandler())
-            ->addMiddleware(new WebSocketMiddleware\PingResponder());
+            ->addMiddleware(new WebSocketMiddleware\CloseHandler)
+            ->addMiddleware(new WebSocketMiddleware\PingResponder);
 
         $client->onText(function (WebSocketClient $client, WebSocketConnection $connection, WebSocketMessage $message) use ($listeners) {
             $receivedAt = Carbon::now();

From 11559d1cd3418422bd3109190ee9c27b3d8b641d Mon Sep 17 00:00:00 2001
From: parsilver <magician_canobi@hotmail.com>
Date: Mon, 2 Mar 2026 12:02:18 +0700
Subject: [PATCH 3/7] fix(ci): bump minimum PHP to 8.2 and update CI matrix

PHP 8.1 is EOL and pestphp/pest ^2.15 can no longer resolve
dependencies on PHP 8.1 with --prefer-lowest due to
brianium/paratest requiring PHP 8.2+.
---
 .github/workflows/run-tests.yml | 2 +-
 composer.json                   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index 0bdaf1f..06101de 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -9,7 +9,7 @@ jobs:
       fail-fast: true
       matrix:
         os: [ubuntu-latest, windows-latest]
-        php: [8.2, 8.1]
+        php: [8.3, 8.2]
         stability: [prefer-lowest, prefer-stable]
 
     name: P${{ matrix.php }} - ${{ matrix.stability }} - ${{ matrix.os }}
diff --git a/composer.json b/composer.json
index 808f7f8..53881db 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,7 @@
         }
     ],
     "require": {
-        "php": "^8.1",
+        "php": "^8.2",
         "farzai/support": "^1.2",
         "farzai/transport": "^2.1",
         "phrity/websocket": "^3.0"

From 6175ef5274ebd1afd34577ea118d736a406faa24 Mon Sep 17 00:00:00 2001
From: parsilver <magician_canobi@hotmail.com>
Date: Mon, 2 Mar 2026 12:06:11 +0700
Subject: [PATCH 4/7] ci: add PHP 8.4 and 8.5 to test matrix

---
 .github/workflows/run-tests.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index 06101de..136d11c 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -9,7 +9,7 @@ jobs:
       fail-fast: true
       matrix:
         os: [ubuntu-latest, windows-latest]
-        php: [8.3, 8.2]
+        php: [8.5, 8.4, 8.3, 8.2]
         stability: [prefer-lowest, prefer-stable]
 
     name: P${{ matrix.php }} - ${{ matrix.stability }} - ${{ matrix.os }}

From 1f2fd24a98e94db54aef613e478b3a7948d48090 Mon Sep 17 00:00:00 2001
From: parsilver <magician_canobi@hotmail.com>
Date: Mon, 2 Mar 2026 12:07:34 +0700
Subject: [PATCH 5/7] ci: exclude PHP 8.5 prefer-lowest from test matrix

pestphp/pest ^2 cannot resolve dependencies on PHP 8.5 with
--prefer-lowest due to brianium/paratest version conflicts.
---
 .github/workflows/run-tests.yml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index 136d11c..1671ce9 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -11,6 +11,9 @@ jobs:
         os: [ubuntu-latest, windows-latest]
         php: [8.5, 8.4, 8.3, 8.2]
         stability: [prefer-lowest, prefer-stable]
+        exclude:
+          - php: 8.5
+            stability: prefer-lowest
 
     name: P${{ matrix.php }} - ${{ matrix.stability }} - ${{ matrix.os }}
 

From a3368eb7495f65db2f8e61772c17840b4becedf3 Mon Sep 17 00:00:00 2001
From: parsilver <magician_canobi@hotmail.com>
Date: Mon, 2 Mar 2026 12:09:00 +0700
Subject: [PATCH 6/7] ci: remove PHP 8.5 from test matrix

pestphp/pest ^2 does not support PHP 8.5 in any version.
---
 .github/workflows/run-tests.yml | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index 1671ce9..1272433 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -9,11 +9,8 @@ jobs:
       fail-fast: true
       matrix:
         os: [ubuntu-latest, windows-latest]
-        php: [8.5, 8.4, 8.3, 8.2]
+        php: [8.4, 8.3, 8.2]
         stability: [prefer-lowest, prefer-stable]
-        exclude:
-          - php: 8.5
-            stability: prefer-lowest
 
     name: P${{ matrix.php }} - ${{ matrix.stability }} - ${{ matrix.os }}
 

From b7d51d1fc4e98e55b23536a9509d7c789e1e6b00 Mon Sep 17 00:00:00 2001
From: parsilver <magician_canobi@hotmail.com>
Date: Mon, 2 Mar 2026 12:16:07 +0700
Subject: [PATCH 7/7] test: increase test coverage for transport v2 migration

- AbstractResponseDecorator: test jsonOrNull, toArray, PSR-7 delegation
- ResponseWithValidateErrorCode: test null error code, throw chaining
- ClientBuilder: test setHttpClient, setLogger, setRetries
- PendingRequest: test string body, no-options request, path normalization, createResponse
---
 tests/ClientBuilderTest.php     | 36 ++++++++++++++++
 tests/PendingRequestTest.php    | 59 ++++++++++++++++++++++++++
 tests/ResponseErrorCodeTest.php | 75 +++++++++++++++++++++++++++++++++
 3 files changed, 170 insertions(+)

diff --git a/tests/ClientBuilderTest.php b/tests/ClientBuilderTest.php
index 1b45b72..75142f0 100644
--- a/tests/ClientBuilderTest.php
+++ b/tests/ClientBuilderTest.php
@@ -26,3 +26,39 @@
 
     $client->market()->balances();
 })->throws(InvalidArgumentException::class, 'Secret key is required');
+
+it('can set custom http client', function () {
+    $httpClient = $this->createMock(\Psr\Http\Client\ClientInterface::class);
+
+    $client = ClientBuilder::create()
+        ->setCredentials('test', 'secret')
+        ->setHttpClient($httpClient)
+        ->build();
+
+    expect($client)->toBeInstanceOf(Client::class);
+});
+
+it('can set custom logger', function () {
+    $logger = $this->createMock(\Psr\Log\LoggerInterface::class);
+
+    $client = ClientBuilder::create()
+        ->setCredentials('test', 'secret')
+        ->setLogger($logger)
+        ->build();
+
+    expect($client)->toBeInstanceOf(Client::class);
+});
+
+it('can set retries', function () {
+    $client = ClientBuilder::create()
+        ->setCredentials('test', 'secret')
+        ->setRetries(5)
+        ->build();
+
+    expect($client)->toBeInstanceOf(Client::class);
+});
+
+it('should throw exception when retries is negative', function () {
+    ClientBuilder::create()
+        ->setRetries(-1);
+})->throws(\InvalidArgumentException::class, 'Retries must be greater than or equal to 0.');
diff --git a/tests/PendingRequestTest.php b/tests/PendingRequestTest.php
index c88fc3f..06e3ca9 100644
--- a/tests/PendingRequestTest.php
+++ b/tests/PendingRequestTest.php
@@ -149,3 +149,62 @@
     expect($request->getUri()->getQuery())->toBe('symbol=BTC');
     expect($request->getHeaderLine('Content-Type'))->toBe('application/json');
 });
+
+it('can createRequest with string body', function () {
+    $client = ClientBuilder::create()
+        ->setCredentials('test', 'secret')
+        ->build();
+
+    $pending = new PendingRequest($client, 'POST', '/api/market/orders');
+
+    $request = $pending->createRequest('POST', '/api/market/orders', [
+        'body' => 'raw-string-body',
+    ]);
+
+    expect($request)->toBeInstanceOf(\Psr\Http\Message\RequestInterface::class);
+    expect($request->getBody()->getContents())->toBe('raw-string-body');
+});
+
+it('can createRequest without optional parameters', function () {
+    $client = ClientBuilder::create()
+        ->setCredentials('test', 'secret')
+        ->build();
+
+    $pending = new PendingRequest($client, 'GET', '/api/market/ticker');
+
+    $request = $pending->createRequest('GET', '/api/market/ticker');
+
+    expect($request)->toBeInstanceOf(\Psr\Http\Message\RequestInterface::class);
+    expect($request->getMethod())->toBe('GET');
+    expect($request->getUri()->getPath())->toBe('/api/market/ticker');
+    expect($request->getUri()->getQuery())->toBe('');
+});
+
+it('normalizes path with leading slash', function () {
+    $client = ClientBuilder::create()
+        ->setCredentials('test', 'secret')
+        ->build();
+
+    $pending = new PendingRequest($client, 'GET', 'api/market/ticker');
+
+    $request = $pending->createRequest('GET', 'api/market/ticker');
+
+    expect($request->getUri()->getPath())->toBe('/api/market/ticker');
+});
+
+it('can createResponse wrapping PSR response', function () {
+    $client = ClientBuilder::create()
+        ->setCredentials('test', 'secret')
+        ->build();
+
+    $pending = new PendingRequest($client, 'GET', '/api/market/ticker');
+
+    $psrRequest = $this->createMock(\Psr\Http\Message\RequestInterface::class);
+    $psrResponse = \Farzai\Bitkub\Tests\MockHttpClient::response(200, json_encode(['error' => 0]));
+
+    $response = $pending->createResponse($psrRequest, $psrResponse);
+
+    expect($response)->toBeInstanceOf(\Farzai\Transport\Contracts\ResponseInterface::class);
+    expect($response)->toBeInstanceOf(\Farzai\Bitkub\Responses\ResponseWithValidateErrorCode::class);
+    expect($response->statusCode())->toBe(200);
+});
diff --git a/tests/ResponseErrorCodeTest.php b/tests/ResponseErrorCodeTest.php
index eb961b8..1328ffa 100644
--- a/tests/ResponseErrorCodeTest.php
+++ b/tests/ResponseErrorCodeTest.php
@@ -78,3 +78,78 @@
 
     new BitkubResponseErrorCodeException($psrResponse);
 })->throws(\Exception::class, 'Error code not found.');
+
+it('should not throw exception when error code is null', function () {
+    $psrRequest = $this->createMock(PsrRequestInterface::class);
+    $psrResponse = MockHttpClient::response(200, json_encode([
+        'result' => 'ok',
+    ]));
+
+    $response = new Response($psrRequest, $psrResponse);
+    $response = new ResponseWithValidateErrorCode($response);
+
+    $result = $response->throw();
+
+    expect($result)->toBeInstanceOf(ResponseWithValidateErrorCode::class);
+});
+
+it('throw returns static for chaining', function () {
+    $psrRequest = $this->createMock(PsrRequestInterface::class);
+    $psrResponse = MockHttpClient::response(200, json_encode([
+        'error' => 0,
+    ]));
+
+    $response = new Response($psrRequest, $psrResponse);
+    $response = new ResponseWithValidateErrorCode($response);
+
+    $result = $response->throw();
+
+    expect($result)->toBe($response);
+});
+
+it('decorator delegates jsonOrNull method', function () {
+    $psrRequest = $this->createMock(PsrRequestInterface::class);
+    $psrResponse = MockHttpClient::response(200, json_encode([
+        'error' => 0,
+        'result' => ['balance' => 100],
+    ]));
+
+    $response = new Response($psrRequest, $psrResponse);
+    $response = new ResponseWithValidateErrorCode($response);
+
+    expect($response->jsonOrNull('result'))->toBe(['balance' => 100]);
+    expect($response->jsonOrNull('nonexistent'))->toBeNull();
+});
+
+it('decorator delegates toArray method', function () {
+    $psrRequest = $this->createMock(PsrRequestInterface::class);
+    $psrResponse = MockHttpClient::response(200, json_encode([
+        'error' => 0,
+        'result' => 'ok',
+    ]));
+
+    $response = new Response($psrRequest, $psrResponse);
+    $response = new ResponseWithValidateErrorCode($response);
+
+    expect($response->toArray())->toBe(['error' => 0, 'result' => 'ok']);
+});
+
+it('decorator delegates PSR-7 getStatusCode', function () {
+    $psrRequest = $this->createMock(PsrRequestInterface::class);
+    $psrResponse = MockHttpClient::response(201, json_encode(['error' => 0]));
+
+    $response = new Response($psrRequest, $psrResponse);
+    $response = new ResponseWithValidateErrorCode($response);
+
+    expect($response->getStatusCode())->toBe(201);
+});
+
+it('decorator delegates PSR-7 getBody', function () {
+    $psrRequest = $this->createMock(PsrRequestInterface::class);
+    $psrResponse = MockHttpClient::response(200, json_encode(['error' => 0]));
+
+    $response = new Response($psrRequest, $psrResponse);
+    $response = new ResponseWithValidateErrorCode($response);
+
+    expect($response->getBody())->toBeInstanceOf(\Psr\Http\Message\StreamInterface::class);
+});