From 4b62d72e7e3afc18a90176791e9c042ced751ed3 Mon Sep 17 00:00:00 2001
From: kriptonovac <kriptonovac@gmail.com>
Date: Tue, 11 Jun 2024 13:08:44 +0000
Subject: [PATCH 1/2] Add read from relay feature

---
 src/Filter/Filter.php             | 193 ++++++++++++++++++++++++++++++
 src/FilterInterface.php           |  82 +++++++++++++
 src/Message/CloseMessage.php      |  28 +++++
 src/Message/RequestMessage.php    |  47 ++++++++
 src/Request/Request.php           |  85 +++++++++++++
 src/RequestInterface.php          |  15 +++
 src/Subscription/Subscription.php |  19 +++
 src/SubscriptionInterface.php     |  10 ++
 tests/RequestTest.php             |  42 +++++++
 9 files changed, 521 insertions(+)
 create mode 100644 src/Filter/Filter.php
 create mode 100644 src/FilterInterface.php
 create mode 100644 src/Message/CloseMessage.php
 create mode 100644 src/Message/RequestMessage.php
 create mode 100644 src/Request/Request.php
 create mode 100644 src/RequestInterface.php
 create mode 100644 src/Subscription/Subscription.php
 create mode 100644 src/SubscriptionInterface.php
 create mode 100644 tests/RequestTest.php

diff --git a/src/Filter/Filter.php b/src/Filter/Filter.php
new file mode 100644
index 0000000..f09be12
--- /dev/null
+++ b/src/Filter/Filter.php
@@ -0,0 +1,193 @@
+<?php
+
+declare(strict_types=1);
+
+namespace swentel\nostr\Filter;
+
+use swentel\nostr\FilterInterface;
+
+class Filter implements FilterInterface
+{
+    /**
+     * A list of event ids
+     */
+    public array $id;
+
+    /**
+     * A list of lowercase pubkeys, the pubkey of an event must be one of these
+     */
+    public array $authors;
+
+    /**
+     * A list of a kind numbers
+     */
+    public array $kinds;
+
+    /**
+     * A list of #e tag values (list of event ids)
+     */
+    public array $etags;
+
+    /**
+     * A list of #p tag values (list of pubkeys).
+     */
+    public array $ptags;
+
+    /**
+     * An integer unix timestamp in seconds, events must be newer than this to pass
+     */
+    public int $since;
+
+    /**
+     * An integer unix timestamp in seconds, events must be older than this to pass 
+     */
+    public int $until;
+
+    /**
+     * Maximum number of events relays SHOULD return in the initial query
+     */
+    public int $limit;
+
+    /**
+     * Set the authors for the Filter object.
+     *
+     * @param array $pubkey The array of authors to set.
+     */
+    public function setAuthors(array $pubkeys): static
+    {
+        foreach($pubkeys as $key){
+            if(!$this->isLowercaseHex($key)){
+                throw new \RuntimeException("Author pubkeys must be an array of 64-character lowercase hex values");
+            }
+        }
+        $this->authors = $pubkeys;
+        return $this;
+    }
+
+    /**
+     * Set the kinds for the Filter object.
+     *
+     * @param array $kinds The array of kinds to set.
+     */
+    public function setKinds(array $kinds): static
+    {
+        $this->kinds = $kinds;
+        return $this;
+    }
+
+    /**
+     * Set the #e tag for the Filter object.
+     *
+     * @param array $etag The array of tag to set.
+     */
+    public function setETag(array $etags): static
+    {
+        foreach($etags as $tag){
+            if(!$this->isLowercaseHex($tag)){
+                throw new \RuntimeException("#e tags must be an array of 64-character lowercase hex values");
+            }
+        }
+        $this->etags = $etags;
+        return $this;
+    }
+
+    /**
+     * Set the #p tag for the Filter object.
+     *
+     * @param array $ptag The array of tag to set.
+     */
+    public function setPTag(array $ptags): static
+    {
+        // Check IF array contain exact 64-character lowercase hex values
+        foreach($ptags as $tag){
+            if(!$this->isLowercaseHex($tag)){
+                throw new \RuntimeException("#e tags must be an array of 64-character lowercase hex values");
+            }
+        }
+        $this->ptags = $ptags;
+        return $this;
+    }
+
+    /**
+     * Set the since for the Filter object.
+     *
+     * @param int $since The limit to set.
+     */
+    public function setSince(int $since): static
+    {
+        $this->since = $since;
+        return $this;
+    }
+
+    /**
+     * Set the until for the Filter object.
+     *
+     * @param int $until The limit to set.
+     */
+    public function setUntil(int $until): static
+    {
+        $this->until = $until;
+        return $this;
+    }
+
+    /**
+     * Set the limit for the Filter object.
+     *
+     * @param int $limit The limit to set.
+     */
+    public function setLimit(int $limit): static
+    {
+        $this->limit = $limit;
+        return $this;
+    }
+
+    /**
+     * Check if a given string is a 64-character lowercase hexadecimal value.
+     *
+     * @param string $string The string to check.
+     * @return bool True if the string is a 64-character lowercase hexadecimal value, false otherwise.
+     */
+    public function isLowercaseHex($string): bool 
+    {
+        // Regular expression to match 64-character lowercase hexadecimal value
+        $pattern = '/^[a-f0-9]{64}$/';
+    
+        // Check if the string matches the pattern
+        return preg_match($pattern, $string) === 1;
+    }
+
+    /**
+     * Check if a given timestamp is valid.
+     *
+     * @param mixed $timestamp The timestamp to check.
+     * @return bool True if the timestamp is valid, false otherwise.
+     */
+    public function isValidTimestamp($timestamp): bool
+    {
+        // Convert the timestamp to seconds
+        $timestamp = (int) $timestamp;
+    
+        // Check if the timestamp is valid
+        return ($timestamp !== 0 && $timestamp !== false && $timestamp !== -1);
+    }
+
+    /**
+     * Return an array representation of the object by iterating through its properties.
+     *
+     * @return array The array representation of the object.
+     */
+    public function toArray(): array
+    {
+        $array = [];
+        foreach (get_object_vars($this) as $key => $val) {
+            if($key === 'etags'){
+                $array['#e'] = $val;
+            }elseif($key === 'ptags'){
+                $array['#p'] = $val;
+            }else{
+                $array[$key] = $val;
+            }
+        }
+        return $array;
+    }
+}
\ No newline at end of file
diff --git a/src/FilterInterface.php b/src/FilterInterface.php
new file mode 100644
index 0000000..feaa1d3
--- /dev/null
+++ b/src/FilterInterface.php
@@ -0,0 +1,82 @@
+<?php
+
+declare(strict_types=1);
+
+namespace swentel\nostr;
+
+interface FilterInterface
+{
+    /**
+     * Set the authors for the Filter object.
+     *
+     * @param array $pubkey The array of authors to set.
+     */
+    public function setAuthors(array $pubkey): static;
+
+    /**
+     * Set the kinds for the Filter object.
+     *
+     * @param array $kinds The array of kinds to set.
+     */
+    public function setKinds(array $kinds): static;
+
+    /**
+     * Set the tag for the Filter object.
+     *
+     * @param array $tag The array of tag to set.
+     */
+    public function setETag(array $tag): static;
+
+
+    /**
+     * Set the #p tag for the Filter object.
+     *
+     * @param array $ptag The array of tag to set.
+     */
+    public function setPTag(array $ptag): static;
+
+    /**
+     * Set the since for the Filter object.
+     *
+     * @param int $since The limit to set.
+     */
+    public function setSince(int $since): static;
+
+    /**
+     * Set the until for the Filter object.
+     *
+     * @param int $until The limit to set.
+     */
+    public function setUntil(int $until): static;
+   
+    /**
+     * Set the limit for the Filter object.
+     *
+     * @param int $limit The limit to set.
+     */
+    public function setLimit(int $limit):static;
+
+    /**
+     * Check if a given string is a 64-character lowercase hexadecimal value.
+     *
+     * @param string $string The string to check.
+     * @return bool True if the string is a 64-character lowercase hexadecimal value, false otherwise.
+     */
+    public function isLowercaseHex($string): bool;
+
+    /**
+     * Check if a given timestamp is valid.
+     *
+     * @param mixed $timestamp The timestamp to check.
+     * @return bool True if the timestamp is valid, false otherwise.
+     */
+    public function isValidTimestamp($timestamp): bool;
+
+    /**
+     * Return an array representation of the object by iterating through its properties.
+     *
+     * @return array The array representation of the object.
+     */
+    public function toArray(): array;
+
+}
\ No newline at end of file
diff --git a/src/Message/CloseMessage.php b/src/Message/CloseMessage.php
new file mode 100644
index 0000000..5cd889b
--- /dev/null
+++ b/src/Message/CloseMessage.php
@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace swentel\nostr\Message;
+
+use swentel\nostr\MessageInterface;
+
+class CloseMessage implements MessageInterface
+{
+    /**
+     * Subscription ID
+     */
+    protected string $subscriptionId;
+
+    public function __construct(string $subscriptionId)
+    {
+        $this->subscriptionId = $subscriptionId;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function generate(): string
+    {
+        return '["CLOSE", "' . $this->subscriptionId . '"]';
+    }
+}
diff --git a/src/Message/RequestMessage.php b/src/Message/RequestMessage.php
new file mode 100644
index 0000000..8abfd17
--- /dev/null
+++ b/src/Message/RequestMessage.php
@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types=1);
+
+namespace swentel\nostr\Message;
+
+use swentel\nostr\MessageInterface;
+use swentel\nostr\Filter;
+
+class RequestMessage implements MessageInterface
+{
+    /**
+     * An arbitrary, non-empty string of max length 64 chars
+     */
+    protected string $subscriptionId;
+
+    /**
+     * Array of filters
+     */
+    protected array $filters = [];
+
+    /**
+     * Constructor for the RequestMessage class.
+     * Initializes the subscription ID and filters array based on the provided parameters.
+     *
+     * @param string $subscriptionId The ID of the subscription
+     * @param array $filters An array of filters to be applied
+     */
+    public function __construct(string $subscriptionId, array $filters)
+    {
+        $this->subscriptionId = $subscriptionId;
+        foreach($filters as $filter){
+            $this->filters[] = $filter->toArray();
+        }
+    }
+
+    /**
+     * Generates a JSON-encoded request array by merging the subscription ID and filters array.
+     *
+     * @return string The JSON-encoded request array
+     */
+    public function generate(): string
+    {
+        $requestArray = array_merge(["REQ", $this->subscriptionId], $this->filters);
+        return json_encode($requestArray, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
+    }
+}
\ No newline at end of file
diff --git a/src/Request/Request.php b/src/Request/Request.php
new file mode 100644
index 0000000..95c4507
--- /dev/null
+++ b/src/Request/Request.php
@@ -0,0 +1,85 @@
+<?php
+
+declare(strict_types=1);
+
+namespace swentel\nostr\Request;
+
+use swentel\nostr\Message\RequestMessage;
+use swentel\nostr\RequestInterface;
+use WebSocket;
+
+class Request implements RequestInterface
+{
+    /**
+     * Repay url
+     */
+    private string $url;
+
+    /**
+     * Request message sent to relay
+     */
+    private string $payload;
+
+    /**
+     * Constructor for the Request class.
+     * Initializes the url and payload properties based on the provided websocket and message.
+     */
+    public function __construct(string $websocket, $message)
+    {
+        $this->url = $websocket;
+        $this->payload = $message->generate();
+    }
+
+    /**
+     * Method to send a request using WebSocket client, receive responses, and handle errors.
+     *
+     * @return array The array of responses received or an error message if connection fails.
+     */
+    public function send(): array
+    {
+        try {
+            $client = new WebSocket\Client($this->url);
+            $client->text($this->payload);
+
+            $result = [];
+
+            /**
+             * When sending 'CLOSE' request to close a subscription, it is not guaranteed that we
+             * will receive a response confirming that the subscription with the given ID is closed 
+             * as the protocol does not mandate a specific response for a "CLOSE" request
+             * 
+             * We can handle this either by: 
+             *  - closing connection upon sending the request
+             *  - waiting for a certain period to see if further events are received for that subscription ID
+             *  - waiting for ping from server to close connection (in which case the server indicates the 
+             *    connection is still alive, but it does not confirm the closure of the subscription)
+             */
+            while ($response = $client->receive()) {
+                if ($response instanceof WebSocket\Message\Ping) {
+                    $client->disconnect();
+                    return $result;
+                } elseif ($response instanceof WebSocket\Message\Text) {
+                    $response = json_decode($response->getContent());
+                    if ($response[0] === 'NOTICE' || $response[0] === 'CLOSED') {
+                        $client->disconnect();
+                        throw new \RuntimeException($response[0] === 'NOTICE' ? $response[1] : $response[2]);
+                    } elseif ($response[0] === 'EOSE') {
+                        break;
+                    } else {
+                        $result[] = $response;
+                    }
+                }
+            }
+            $client->disconnect();
+        } catch (WebSocket\ConnectionException $e) {
+            $result = [
+              'ERROR',
+              '',
+              false,
+              $e->getMessage()
+            ];
+        }
+
+        return $result;
+    }
+}
\ No newline at end of file
diff --git a/src/RequestInterface.php b/src/RequestInterface.php
new file mode 100644
index 0000000..c59cff9
--- /dev/null
+++ b/src/RequestInterface.php
@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace swentel\nostr;
+
+interface RequestInterface
+{
+    /**
+     * Send the request to the relay.
+     *
+     * @return CommandResultInterface
+     */
+    public function send(): array;
+}
diff --git a/src/Subscription/Subscription.php b/src/Subscription/Subscription.php
new file mode 100644
index 0000000..6a6cba5
--- /dev/null
+++ b/src/Subscription/Subscription.php
@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace swentel\nostr\Subscription;
+
+use swentel\nostr\SubscriptionInterface;
+
+class Subscription implements SubscriptionInterface
+{
+    public function setId($length = 64): string
+    {
+        // String of all alphanumeric character
+        $str_result = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
+
+        // Shuffle the $str_result and returns substring of specified length
+        return substr(str_shuffle($str_result), 0, $length);
+    }
+}
\ No newline at end of file
diff --git a/src/SubscriptionInterface.php b/src/SubscriptionInterface.php
new file mode 100644
index 0000000..872dccd
--- /dev/null
+++ b/src/SubscriptionInterface.php
@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace swentel\nostr;
+
+interface SubscriptionInterface
+{
+    public function setId($length): string;
+}
\ No newline at end of file
diff --git a/tests/RequestTest.php b/tests/RequestTest.php
new file mode 100644
index 0000000..436c131
--- /dev/null
+++ b/tests/RequestTest.php
@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+use PHPUnit\Framework\TestCase;
+use swentel\nostr\Subscription\Subscription;
+use swentel\nostr\Filter\Filter;
+use swentel\nostr\Message\RequestMessage;
+use swentel\nostr\Request\Request;
+use WebSocket\Client;
+
+class RequestTest extends TestCase
+{
+    /**
+     * Tests sending a request to a relay.
+     */
+    public function testSendRequestToRelay()
+    {
+        $relayUrl = 'wss://relay.damus.io';
+
+        $subscription = new Subscription();
+        $subscriptionId = $subscription->setId();
+
+        $filter = new Filter();
+        $filter->setKinds([1]);
+        $filter->setLimit(3);
+
+        $filters = [$filter];
+
+        // Mocking the WebSocket\Client
+        $mockClient = $this->getMockBuilder(Client::class)
+            ->setConstructorArgs([$relayUrl])
+            ->getMock();
+
+        $requestMessage = new RequestMessage($subscriptionId, $filters);
+        $request = new Request($relayUrl, $requestMessage, $mockClient);
+
+        $result = $request->send();
+
+        $this->assertNotEmpty($result, 'Request send result should not be empty');
+    }
+}

From 5601f87e2f17c0af47581f96f7d0eb978fd70047 Mon Sep 17 00:00:00 2001
From: kriptonovac <kriptonovac@gmail.com>
Date: Tue, 18 Jun 2024 09:30:17 +0000
Subject: [PATCH 2/2] Update PR: removed unused statement, corrected typos,
 changed names of setPTag method to setLowercasePTags, changed name of
 setETags method to setLowercaseETags

---
 src/Filter/Filter.php             | 32 +++++++++++++++----------------
 src/FilterInterface.php           | 12 +++++-------
 src/Message/RequestMessage.php    |  4 ++--
 src/Request/Request.php           | 18 ++++++++---------
 src/Subscription/Subscription.php |  3 +--
 src/SubscriptionInterface.php     |  2 +-
 6 files changed, 32 insertions(+), 39 deletions(-)

diff --git a/src/Filter/Filter.php b/src/Filter/Filter.php
index f09be12..870a908 100644
--- a/src/Filter/Filter.php
+++ b/src/Filter/Filter.php
@@ -39,7 +39,7 @@ class Filter implements FilterInterface
     public int $since;
 
     /**
-     * An integer unix timestamp in seconds, events must be older than this to pass 
+     * An integer unix timestamp in seconds, events must be older than this to pass
      */
     public int $until;
 
@@ -55,8 +55,8 @@ class Filter implements FilterInterface
      */
     public function setAuthors(array $pubkeys): static
     {
-        foreach($pubkeys as $key){
-            if(!$this->isLowercaseHex($key)){
+        foreach($pubkeys as $key) {
+            if(!$this->isLowercaseHex($key)) {
                 throw new \RuntimeException("Author pubkeys must be an array of 64-character lowercase hex values");
             }
         }
@@ -80,10 +80,10 @@ public function setKinds(array $kinds): static
      *
      * @param array $etag The array of tag to set.
      */
-    public function setETag(array $etags): static
+    public function setLowercaseETags(array $etags): static
     {
-        foreach($etags as $tag){
-            if(!$this->isLowercaseHex($tag)){
+        foreach($etags as $tag) {
+            if(!$this->isLowercaseHex($tag)) {
                 throw new \RuntimeException("#e tags must be an array of 64-character lowercase hex values");
             }
         }
@@ -96,12 +96,12 @@ public function setETag(array $etags): static
      *
      * @param array $ptag The array of tag to set.
      */
-    public function setPTag(array $ptags): static
+    public function setLowercasePTags(array $ptags): static
     {
         // Check IF array contain exact 64-character lowercase hex values
-        foreach($ptags as $tag){
-            if(!$this->isLowercaseHex($tag)){
-                throw new \RuntimeException("#e tags must be an array of 64-character lowercase hex values");
+        foreach($ptags as $tag) {
+            if(!$this->isLowercaseHex($tag)) {
+                throw new \RuntimeException("#p tags must be an array of 64-character lowercase hex values");
             }
         }
         $this->ptags = $ptags;
@@ -147,11 +147,10 @@ public function setLimit(int $limit): static
      * @param string $string The string to check.
      * @return bool True if the string is a 64-character lowercase hexadecimal value, false otherwise.
      */
-    public function isLowercaseHex($string): bool 
+    public function isLowercaseHex($string): bool
     {
         // Regular expression to match 64-character lowercase hexadecimal value
         $pattern = '/^[a-f0-9]{64}$/';
-    
         // Check if the string matches the pattern
         return preg_match($pattern, $string) === 1;
     }
@@ -166,7 +165,6 @@ public function isValidTimestamp($timestamp): bool
     {
         // Convert the timestamp to seconds
         $timestamp = (int) $timestamp;
-    
         // Check if the timestamp is valid
         return ($timestamp !== 0 && $timestamp !== false && $timestamp !== -1);
     }
@@ -180,14 +178,14 @@ public function toArray(): array
     {
         $array = [];
         foreach (get_object_vars($this) as $key => $val) {
-            if($key === 'etags'){
+            if($key === 'etags') {
                 $array['#e'] = $val;
-            }elseif($key === 'ptags'){
+            } elseif($key === 'ptags') {
                 $array['#p'] = $val;
-            }else{
+            } else {
                 $array[$key] = $val;
             }
         }
         return $array;
     }
-}
\ No newline at end of file
+}
diff --git a/src/FilterInterface.php b/src/FilterInterface.php
index feaa1d3..45a4f6d 100644
--- a/src/FilterInterface.php
+++ b/src/FilterInterface.php
@@ -25,15 +25,14 @@ public function setKinds(array $kinds): static;
      *
      * @param array $tag The array of tag to set.
      */
-    public function setETag(array $tag): static;
-
+    public function setLowercaseETags(array $tag): static;
 
     /**
      * Set the #p tag for the Filter object.
      *
      * @param array $ptag The array of tag to set.
      */
-    public function setPTag(array $ptag): static;
+    public function setLowercasePTags(array $ptag): static;
 
     /**
      * Set the since for the Filter object.
@@ -48,13 +47,13 @@ public function setSince(int $since): static;
      * @param int $until The limit to set.
      */
     public function setUntil(int $until): static;
-   
+
     /**
      * Set the limit for the Filter object.
      *
      * @param int $limit The limit to set.
      */
-    public function setLimit(int $limit):static;
+    public function setLimit(int $limit): static;
 
     /**
      * Check if a given string is a 64-character lowercase hexadecimal value.
@@ -78,5 +77,4 @@ public function isValidTimestamp($timestamp): bool;
      * @return array The array representation of the object.
      */
     public function toArray(): array;
-
-}
\ No newline at end of file
+}
diff --git a/src/Message/RequestMessage.php b/src/Message/RequestMessage.php
index 8abfd17..20b9a53 100644
--- a/src/Message/RequestMessage.php
+++ b/src/Message/RequestMessage.php
@@ -29,7 +29,7 @@ class RequestMessage implements MessageInterface
     public function __construct(string $subscriptionId, array $filters)
     {
         $this->subscriptionId = $subscriptionId;
-        foreach($filters as $filter){
+        foreach($filters as $filter) {
             $this->filters[] = $filter->toArray();
         }
     }
@@ -44,4 +44,4 @@ public function generate(): string
         $requestArray = array_merge(["REQ", $this->subscriptionId], $this->filters);
         return json_encode($requestArray, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
     }
-}
\ No newline at end of file
+}
diff --git a/src/Request/Request.php b/src/Request/Request.php
index 95c4507..6f2281b 100644
--- a/src/Request/Request.php
+++ b/src/Request/Request.php
@@ -4,7 +4,6 @@
 
 namespace swentel\nostr\Request;
 
-use swentel\nostr\Message\RequestMessage;
 use swentel\nostr\RequestInterface;
 use WebSocket;
 
@@ -45,13 +44,12 @@ public function send(): array
 
             /**
              * When sending 'CLOSE' request to close a subscription, it is not guaranteed that we
-             * will receive a response confirming that the subscription with the given ID is closed 
+             * will receive a response confirming that the subscription with the given ID is closed
              * as the protocol does not mandate a specific response for a "CLOSE" request
-             * 
-             * We can handle this either by: 
+             * We can handle this either by:
              *  - closing connection upon sending the request
              *  - waiting for a certain period to see if further events are received for that subscription ID
-             *  - waiting for ping from server to close connection (in which case the server indicates the 
+             *  - waiting for ping from server to close connection (in which case the server indicates the
              *    connection is still alive, but it does not confirm the closure of the subscription)
              */
             while ($response = $client->receive()) {
@@ -73,13 +71,13 @@ public function send(): array
             $client->disconnect();
         } catch (WebSocket\ConnectionException $e) {
             $result = [
-              'ERROR',
-              '',
-              false,
-              $e->getMessage()
+                'ERROR',
+                '',
+                false,
+                $e->getMessage(),
             ];
         }
 
         return $result;
     }
-}
\ No newline at end of file
+}
diff --git a/src/Subscription/Subscription.php b/src/Subscription/Subscription.php
index 6a6cba5..0742422 100644
--- a/src/Subscription/Subscription.php
+++ b/src/Subscription/Subscription.php
@@ -12,8 +12,7 @@ public function setId($length = 64): string
     {
         // String of all alphanumeric character
         $str_result = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
-
         // Shuffle the $str_result and returns substring of specified length
         return substr(str_shuffle($str_result), 0, $length);
     }
-}
\ No newline at end of file
+}
diff --git a/src/SubscriptionInterface.php b/src/SubscriptionInterface.php
index 872dccd..922ccb9 100644
--- a/src/SubscriptionInterface.php
+++ b/src/SubscriptionInterface.php
@@ -7,4 +7,4 @@
 interface SubscriptionInterface
 {
     public function setId($length): string;
-}
\ No newline at end of file
+}