docs: fix PHPDoc types

Author: kenjis

system/Database/BaseResult.php

@@ -12,6 +12,7 @@
 namespace CodeIgniter\Database;
 
 use CodeIgniter\Entity\Entity;
+use stdClass;
 
 /**
  * @template TConnection of object|resource
@@ -116,7 +117,9 @@ public function getResult(string $type = 'object'): array
     /**
      * Returns the results as an array of custom objects.
      *
-     * @return mixed
+     * @phpstan-param class-string $className
+     *
+     * @return array
      */
     public function getCustomResultObject(string $className)
     {
@@ -205,6 +208,9 @@ public function getResultArray(): array
      * Returns the results as an array of objects.
      *
      * If no results, an empty array is returned.
+     *
+     * @return array<int, stdClass>
+     * @phpstan-return list<stdClass>
      */
     public function getResultObject(): array
     {
@@ -248,10 +254,11 @@ public function getResultObject(): array
      *
      * If row doesn't exist, returns null.
      *
-     * @param mixed  $n    The index of the results to return
+     * @param int    $n    The index of the results to return
      * @param string $type The type of result object. 'array', 'object' or class name.
      *
-     * @return mixed
+     * @return array|object|stdClass|null
+     * @phpstan-return ($type is 'object' ? stdClass|null : ($type is 'array' ? array|null : object|null))
      */
     public function getRow($n = 0, string $type = 'object')
     {
@@ -285,7 +292,7 @@ public function getRow($n = 0, string $type = 'object')
      *
      * If row doesn't exists, returns null.
      *
-     * @return mixed
+     * @return array|null
      */
     public function getCustomRowObject(int $n, string $className)
     {
@@ -309,7 +316,7 @@ public function getCustomRowObject(int $n, string $className)
      *
      * If row doesn't exist, returns null.
      *
-     * @return mixed
+     * @return array|null
      */
     public function getRowArray(int $n = 0)
     {
@@ -330,7 +337,7 @@ public function getRowArray(int $n = 0)
      *
      * If row doesn't exist, returns null.
      *
-     * @return mixed
+     * @return object|stdClass|null
      */
     public function getRowObject(int $n = 0)
     {
@@ -377,7 +384,7 @@ public function setRow($key, $value = null)
     /**
      * Returns the "first" row of the current results.
      *
-     * @return mixed
+     * @return array|object|null
      */
     public function getFirstRow(string $type = 'object')
     {
@@ -389,7 +396,7 @@ public function getFirstRow(string $type = 'object')
     /**
      * Returns the "last" row of the current results.
      *
-     * @return mixed
+     * @return array|object|null
      */
     public function getLastRow(string $type = 'object')
     {
@@ -401,7 +408,7 @@ public function getLastRow(string $type = 'object')
     /**
      * Returns the "next" row of the current results.
      *
-     * @return mixed
+     * @return array|object|null
      */
     public function getNextRow(string $type = 'object')
     {
@@ -416,7 +423,7 @@ public function getNextRow(string $type = 'object')
     /**
      * Returns the "previous" row of the current results.
      *
-     * @return mixed
+     * @return array|object|null
      */
     public function getPreviousRow(string $type = 'object')
     {
@@ -435,7 +442,7 @@ public function getPreviousRow(string $type = 'object')
     /**
      * Returns an unbuffered row and move the pointer to the next row.
      *
-     * @return mixed
+     * @return array|object|null
      */
     public function getUnbufferedRow(string $type = 'object')
     {