Allow custom functions and rewrite rules (#106)

* Allow adding custom functions/rewrite rules

* Update README.md

* StyleCI changes

Author: daverogers

README.md

@@ -34,6 +34,7 @@ In order to reduce clutter it is preferable to create a separate Service Provide
         }
     }
     ```
+
 1. Add a line to `app/Providers/AppServiceProvider.php` within the `register()` method:
     ```php
     $this->app->register(MySQLiteServiceProvider::class);
@@ -93,6 +94,32 @@ In order to reduce clutter it is preferable to create a separate Service Provide
 #### Comparison
 - [least(mixed ...)](https://github.com/Vectorface/MySQLite/blob/master/src/Vectorface/MySQLite/MySQL/Comparison.php)
 
+# Custom Functionality
+While this package aims to cover common functionality, there are times when you need support for a function quickly or a custom function that is unique to your application. This is easy to do with two methods from the `boot()` method of your service provider class:
+
+```php
+<?php
+
+class MySQLiteServiceProvider extends ServiceProvider
+{
+    ...
+
+    public function boot()
+    {
+        $connection = $this->app->get('db')->connection();
+        
+        if ($connection->getDriverName() === 'sqlite') {
+            $connection
+                ->addRewriteRule('/CURDATE\(\)/', "date('now')")
+                ->addFunction('CURDATE', fn() => CarbonImmutable::today()->toDateString(), 0);
+        }
+    }
+}
+```
+
+- `addRewriteRule()` will replace a string in your query using regex, should Sqlite have a native function that could be used as a 1:1 replacement.
+- `addFunction()` uses PDO `sqliteCreateFunction()` to register a custom function with PHP in the event that Sqlite doesn't have a drop-in replacement or if logic is more complicated. [Read More][sqlitecreatefunction].
+
 # Contributing
 Want to file a bug, contribute some code, improve documentation, or request a feature? Awesome Sauce! Read up on our guidelines for [contributing][contributing].  All contributions must follow our [Code of Conduct][codeofconduct].
 
@@ -114,3 +141,4 @@ License: (MIT) https://github.com/Vectorface/MySQLite/blob/master/LICENSE
 [contributing]: ./.github/contributing.md
 [issue]: https://github.com/spam-n-eggs/laravel-mysqlite/issues
 [codeofconduct]:./.github/CODE_OF_CONDUCT.md
+[sqlitecreatefunction]: https://www.php.net/manual/en/pdo.sqlitecreatefunction.php

src/Mhorninger/MySQLite/MethodRewriteConstants.php

@@ -5,17 +5,17 @@
 class MethodRewriteConstants
 {
     const METHOD_REPLACEMENTS = [
-        '/(DATE_ADD)(?=.*?, INTERVAL.*?\\))/' => 'datetime',
-        '/INTERVAL (?=.*?\\))/' => '\'+',
-        '/INTERVAL (?=.*?\\))/' => '\'+',
-        '/SECOND(?=\\))/' => 'seconds\'',
-        '/MINUTE(?=\\))/' => 'minutes\'',
-        '/HOUR(?=\\))/' => 'hours\'',
-        '/DAY(?=\\))/' => 'days\'',
-        '/WEEK(?=\\))/' => 'weeks\'',
-        '/MONTH(?=\\))/' => 'months\'',
-        '/YEAR(?=\\))/' => 'years\'',
-        '/LEFT(?=.*?, .*?\\))/' => '`LEFT`',
-        '/RIGHT(?=.*?, .*?\\))/' => '`RIGHT`',
+        ['/(DATE_ADD)(?=.*?, INTERVAL.*?\\))/', 'datetime'],
+        ['/INTERVAL (?=.*?\\))/', '\'+'],
+        ['/INTERVAL (?=.*?\\))/', '\'+'],
+        ['/SECOND(?=\\))/', 'seconds\''],
+        ['/MINUTE(?=\\))/', 'minutes\''],
+        ['/HOUR(?=\\))/', 'hours\''],
+        ['/DAY(?=\\))/', 'days\''],
+        ['/WEEK(?=\\))/', 'weeks\''],
+        ['/MONTH(?=\\))/', 'months\''],
+        ['/YEAR(?=\\))/', 'years\''],
+        ['/LEFT(?=.*?, .*?\\))/', '`LEFT`'],
+        ['/RIGHT(?=.*?, .*?\\))/', '`RIGHT`'],
     ];
 }

src/Mhorninger/MySQLite/MySQLite.php

@@ -12,6 +12,7 @@
 
 /**
  * MySQLite is the extension Vectorface's MySQLite extension.
+ *
  * @see \Vectorface\MySQLite\MySQLite
  */
 class MySQLite extends \Vectorface\MySQLite\MySQLite
@@ -46,14 +47,14 @@ protected static function getPublicMethodData()
     /**
      * Add MySQLite compatibility functions to a PDO object.
      *
-     * @param \PDO $pdo    A PDO instance to which the MySQLite compatibility functions should be added.
-     * @param string[] $fnList A list of functions to create on the SQLite database. (Omit to create all.)
+     * @param  \PDO  $pdo  A PDO instance to which the MySQLite compatibility functions should be added.
+     * @param  string[]  $fnList  A list of functions to create on the SQLite database. (Omit to create all.)
      * @return \PDO Returns a reference to the PDO instance passed in to the function.
      */
     public static function &createFunctions(\PDO &$pdo, array $fnList = null)
     {
         if ($pdo->getAttribute(PDO::ATTR_DRIVER_NAME) !== 'sqlite') {
-            throw new InvalidArgumentException('Expecting a PDO instance using the SQLite driver');
+            throw new \InvalidArgumentException('Expecting a PDO instance using the SQLite driver');
         }
 
         foreach (static::getPublicMethodData() as $method => $paramCount) {
@@ -66,10 +67,10 @@ public static function &createFunctions(\PDO &$pdo, array $fnList = null)
     /**
      * Register a method as an SQLite funtion.
      *
-     * @param PDO $pdo        A PDO instance to which the MySQLite compatibility functions should be added.
-     * @param string $method     The internal method name.
-     * @param int $paramCount The suggested parameter count.
-     * @param string[] $fnList     A list of functions to create on the SQLite database, or empty for all.
+     * @param  PDO  $pdo  A PDO instance to which the MySQLite compatibility functions should be added.
+     * @param  string  $method  The internal method name.
+     * @param  int  $paramCount  The suggested parameter count.
+     * @param  string[]  $fnList  A list of functions to create on the SQLite database, or empty for all.
      * @return bool Returns true if the method was registed. False otherwise.
      */
     protected static function registerMethod(\PDO &$pdo, $method, $paramCount, array $fnList = null)

src/Mhorninger/SQLite/MySQLiteConnection.php

@@ -2,6 +2,7 @@
 
 namespace Mhorninger\SQLite;
 
+use Illuminate\Support\Collection;
 use Mhorninger\MySQLite\MethodRewriteConstants;
 use Mhorninger\MySQLite\MySQLite;
 use Mhorninger\MySQLite\SubstitutionConstants;
@@ -11,27 +12,31 @@
 class MySQLiteConnection extends \Illuminate\Database\SQLiteConnection
 {
     const ESCAPE_CHARS = ['`', '[', '"'];
+    private Collection $rewriteRules;
 
     /**
      * Create a new database connection instance.
      *
-     * @param  \PDO|\Closure     $pdo
-     * @param  string   $database
-     * @param  string   $tablePrefix
-     * @param  array    $config
+     * @param  \PDO|\Closure  $pdo
+     * @param  string  $database
+     * @param  string  $tablePrefix
+     * @param  array  $config
      * @return void
      */
     public function __construct($pdo, $database = '', $tablePrefix = '', array $config = [])
     {
         parent::__construct($pdo, $database, $tablePrefix, $config);
+
+        $this->rewriteRules = collect(MethodRewriteConstants::METHOD_REPLACEMENTS);
+
         //Make sure the PDO is actually a PDO and not a closure.
         $this->pdo = $this->getPdo();
         $this->pdo = MySQLite::createFunctions($this->pdo);
     }
 
     public function run($query, $bindings, \Closure $callback)
     {
-        //Skip on inserts.
+        // Skip on inserts.
         $insertRegex = '/INSERT INTO.*?;/';
         if (0 == preg_match($insertRegex, $query)) {
             $query = $this->methodRewrite($query);
@@ -46,26 +51,41 @@ private function scanQueryForConstants($query)
         $reflection = new ReflectionClass(SubstitutionConstants::class);
         $constants = $reflection->getConstants();
         $placeholders = array_keys($constants);
+
         foreach ($placeholders as $placeholder) {
             $searchFor = '/'.preg_quote($placeholder).'(?!\\(|\\w|\\))/';
             $query = preg_replace($searchFor, "'".$constants[$placeholder]."'", $query);
         }
+
         $reflection = new ReflectionClass(UnquotedSubstitutionConstants::class);
         $methodConstants = $reflection->getConstants();
         $placeholders = array_keys($methodConstants);
+
         foreach ($placeholders as $placeholder) {
             $query = str_replace($placeholder, $methodConstants[$placeholder], $query);
         }
 
         return $query;
     }
 
-    private function methodRewrite($query)
+    public function addFunction(string $function, callable $callback, int $paramCount): self
     {
-        foreach (array_keys(MethodRewriteConstants::METHOD_REPLACEMENTS) as $regex) {
-            $query = preg_replace($regex, MethodRewriteConstants::METHOD_REPLACEMENTS[$regex], $query);
-        }
+        $this->pdo->sqliteCreateFunction($function, $callback, $paramCount);
 
-        return $query;
+        return $this;
+    }
+
+    public function addRewriteRule($regex, $replacement): self
+    {
+        $this->rewriteRules->push([$regex, $replacement]);
+
+        return $this;
+    }
+
+    private function methodRewrite($query)
+    {
+        return $this
+            ->rewriteRules
+            ->reduce(fn ($query, $rule) => preg_replace($rule[0], $rule[1], $query), $query);
     }
 }

test/Mhorninger/MySQLite/MiscellaneousMethodTest.php

@@ -2,6 +2,7 @@
 
 namespace Mhorninger\MySQLite;
 
+use Carbon\CarbonImmutable;
 use Mhorninger\TestCase;
 
 class MiscellaneousMethodTest extends TestCase
@@ -20,4 +21,24 @@ public function testInetNtoaNull()
         $result = $this->conn->selectOne($query);
         $this->assertNull($result->value);
     }
+
+    public function testAddFunction()
+    {
+        $date = CarbonImmutable::today();
+
+        $this->conn->addFunction('TEST_DATE', fn () => $date, 0);
+
+        $result = $this->selectValue('SELECT TEST_DATE()');
+        $this->assertEquals($date, $result);
+    }
+
+    public function testAddRewriteRule()
+    {
+        $date = CarbonImmutable::today();
+
+        $this->conn->addRewriteRule('/TEST_DATE\(\)/', "date('now')");
+
+        $result = $this->selectValue('SELECT TEST_DATE()');
+        $this->assertEquals($date->toDateString(), $result);
+    }
 }

test/Mhorninger/TestCase.php

@@ -8,7 +8,7 @@
 
 class TestCase extends BaseTestCase
 {
-    protected $conn = null;
+    protected ?MySQLiteConnection $conn = null;
 
     public function setUp(): void
     {
@@ -18,4 +18,9 @@ public function setUp(): void
         //Set up the connection.
         $this->conn = new MySQLiteConnection($pdo);
     }
+
+    public function selectValue(string $query)
+    {
+        return collect($this->conn->select($query)[0])->values()->first();
+    }
 }