fix: ensure resource id's are always encoded/decoded when appropriate within a cursor

test: test cursor id encoding/decoding

Author: Gregory Haddow

src/Pagination/Cursor/CursorBuilder.php

@@ -14,7 +14,7 @@ class CursorBuilder
 {
     private Builder|Relation $query;
 
-    private ?ID $id = null;
+    private ID $id;
 
     private string $keyName;
 
@@ -26,6 +26,8 @@ class CursorBuilder
 
     private bool $keySort = true;
 
+    private CursorParser $parser;
+
     /**
      * CursorBuilder constructor.
      *
@@ -34,14 +36,16 @@ class CursorBuilder
      * @param string|null $key
      *      the key column that the before/after cursors related to
      */
-    public function __construct($query, string $key = null)
+    public function __construct($query, ID $id, string $key = null)
     {
         if (!$query instanceof Builder && !$query instanceof Relation) {
             throw new \InvalidArgumentException('Expecting an Eloquent query builder or relation.');
         }
 
         $this->query = $query;
+        $this->id = $id;
         $this->keyName = $key ?: $this->guessKey();
+        $this->parser = new CursorParser(IdParser::make($this->id), $this->keyName);
     }
 
     /**
@@ -58,15 +62,6 @@ public function withDefaultPerPage(?int $perPage): self
         return $this;
     }
 
-    /**
-     * @return $this
-     */
-    public function withIdField(?ID $id): self
-    {
-        $this->id = $id;
-
-        return $this;
-    }
 
     public function withKeySort(bool $keySort): self
     {
@@ -108,8 +103,8 @@ public function paginate(Cursor $cursor, array $columns = ['*']): CursorPaginato
         $this->applyKeySort();
 
         $total = $this->getTotal();
-        $laravelPaginator = $this->query->cursorPaginate($cursor->getLimit(), $columns, 'cursor', $this->convertCursor($cursor));
-        $paginator = new CursorPaginator($laravelPaginator, $cursor, $total);
+        $laravelPaginator = $this->query->cursorPaginate($cursor->getLimit(), $columns, 'cursor', $this->parser->decode($cursor));
+        $paginator = new CursorPaginator($this->parser, $laravelPaginator, $cursor, $total);
 
         return $paginator->withCurrentPath();
     }

src/Pagination/Cursor/CursorPaginator.php

@@ -17,7 +17,7 @@ class CursorPaginator implements \IteratorAggregate, \Countable
     /**
      * CursorPaginator constructor.
      */
-    public function __construct(private readonly LaravelCursorPaginator $laravelPaginator, private readonly Cursor $cursor, private readonly int|null $total = null)
+    public function __construct(private readonly CursorParser $parser, private readonly LaravelCursorPaginator $laravelPaginator, private readonly Cursor $cursor, private readonly int|null $total = null)
     {
         $this->items = Collection::make($this->laravelPaginator->items());
     }
@@ -34,7 +34,7 @@ public function firstItem(): ?string
             return null;
         }
 
-        return $this->laravelPaginator->getCursorForItem($this->items->first(), false)->encode();
+        return $this->parser->encode($this->laravelPaginator->getCursorForItem($this->items->first(), false));
     }
 
     public function lastItem(): ?string
@@ -43,7 +43,7 @@ public function lastItem(): ?string
             return null;
         }
 
-        return $this->laravelPaginator->getCursorForItem($this->items->last())->encode();
+        return $this->parser->encode($this->laravelPaginator->getCursorForItem($this->items->last()));
     }
 
     public function hasMorePages(): bool

src/Pagination/Cursor/CursorParser.php

@@ -0,0 +1,54 @@
+<?php
+
+namespace LaravelJsonApi\Eloquent\Pagination\Cursor;
+
+use Illuminate\Pagination\Cursor as LaravelCursor;
+use LaravelJsonApi\Core\Schema\IdParser;
+
+class CursorParser
+{
+    public function __construct(private IdParser $idParser, private string $keyName)
+    {
+
+    }
+
+    public function encode(LaravelCursor $cursor): string
+    {
+        $key  = $cursor->parameter($this->keyName);
+        if (!$key) {
+            return $cursor->encode();
+        }
+
+        $encodedId = $this->idParser->encode($key);
+        $parameters = $cursor->toArray();
+        unset($parameters['_pointsToNextItems']);
+        $parameters[$this->keyName] = $encodedId;
+
+        $newCursor = new LaravelCursor($parameters, $cursor->pointsToNextItems());
+        return $newCursor->encode();
+    }
+
+    public function decode(Cursor $cursor): ?LaravelCursor
+    {
+        $encodedCursor = $cursor->isBefore() ? $cursor->getBefore() : $cursor->getAfter();
+        if (!is_string($encodedCursor)) {
+            return null;
+        }
+
+        $parameters = json_decode(base64_decode(str_replace(['-', '_'], ['+', '/'], $encodedCursor)), true);
+
+        if (json_last_error() !== JSON_ERROR_NONE) {
+            return null;
+        }
+
+        $pointsToNextItems = $parameters['_pointsToNextItems'];
+        unset($parameters['_pointsToNextItems']);
+        if (isset($parameters[$this->keyName])) {
+            $parameters[$this->keyName] = $this->idParser->decode(
+                $parameters[$this->keyName],
+            );
+        }
+
+        return new LaravelCursor($parameters, $pointsToNextItems);
+    }
+}

src/Pagination/CursorPagination.php

@@ -206,7 +206,6 @@ public function paginate($query, array $page): Page
 
         $paginator = $this
             ->query($query)
-            ->withIdField($this->id)
             ->withDirection($this->direction)
             ->withKeySort($this->keySort)
             ->withDefaultPerPage($this->defaultPerPage)
@@ -227,7 +226,7 @@ public function paginate($query, array $page): Page
      */
     private function query(Builder|Relation $query): CursorBuilder
     {
-        return new CursorBuilder($query, $this->primaryKey);
+        return new CursorBuilder($query, $this->id, $this->primaryKey);
     }
 
     /**