From d10f9694f1b8963c06687bd9ac85cf05953e1bbd Mon Sep 17 00:00:00 2001
From: ignace nyamagana butera <nyamsprod@gmail.com>
Date: Fri, 14 Jan 2022 16:33:48 +0100
Subject: [PATCH] Adding Registering alias feature to the package (#132)

---
 src/Cron/CronExpression.php       | 74 ++++++++++++++++++++++++++++++-
 tests/Cron/CronExpressionTest.php | 57 ++++++++++++++++++++++++
 2 files changed, 130 insertions(+), 1 deletion(-)

diff --git a/src/Cron/CronExpression.php b/src/Cron/CronExpression.php
index fa2acf1a..b13f3d48 100644
--- a/src/Cron/CronExpression.php
+++ b/src/Cron/CronExpression.php
@@ -10,6 +10,7 @@
 use DateTimeZone;
 use Exception;
 use InvalidArgumentException;
+use LogicException;
 use RuntimeException;
 use Webmozart\Assert\Assert;
 
@@ -73,6 +74,77 @@ class CronExpression
         self::MINUTE,
     ];
 
+    /**
+     * @var array<string, string>
+     */
+    private static $registeredAliases = self::MAPPINGS;
+
+    /**
+     * Registered a user defined CRON Expression Alias.
+     *
+     * @throws LogicException If the expression or the alias name are invalid
+     *                         or if the alias is already registered.
+     */
+    public static function registerAlias(string $alias, string $expression): void
+    {
+        try {
+            new self($expression);
+        } catch (InvalidArgumentException $exception) {
+            throw new LogicException("The expression `$expression` is invalid", 0, $exception);
+        }
+
+        $shortcut = strtolower($alias);
+        if (1 !== preg_match('/^@\w+$/', $shortcut)) {
+            throw new LogicException("The alias `$alias` is invalid. It must start with an `@` character and contain alphanumeric (letters, numbers, regardless of case) plus underscore (_).");
+        }
+
+        if (isset(self::$registeredAliases[$shortcut])) {
+            throw new LogicException("The alias `$alias` is already registered.");
+        }
+
+        self::$registeredAliases[$shortcut] = $expression;
+    }
+
+    /**
+     * Unregistered a user defined CRON Expression Alias.
+     *
+     * @throws LogicException If the user tries to unregister a built-in alias
+     */
+    public static function unregisterAlias(string $alias): bool
+    {
+        $shortcut = strtolower($alias);
+        if (isset(self::MAPPINGS[$shortcut])) {
+            throw new LogicException("The alias `$alias` is a built-in alias; it can not be unregistered.");
+        }
+
+        if (!isset(self::$registeredAliases[$shortcut])) {
+            return false;
+        }
+
+        unset(self::$registeredAliases[$shortcut]);
+
+        return true;
+    }
+
+    /**
+     * Tells whether a CRON Expression alias is registered.
+     */
+    public static function supportsAlias(string $alias): bool
+    {
+        return isset(self::$registeredAliases[strtolower($alias)]);
+    }
+
+    /**
+     * Returns all registered aliases as an associated array where the aliases are the key
+     * and their associated expressions are the values.
+     *
+     * @return array<string, string>
+     */
+    public static function getAliases(): array
+    {
+        return self::$registeredAliases;
+    }
+
     /**
      * @deprecated since version 3.0.2, use __construct instead.
      */
@@ -109,7 +181,7 @@ public static function isValidExpression(string $expression): bool
     public function __construct(string $expression, FieldFactoryInterface $fieldFactory = null)
     {
         $shortcut = strtolower($expression);
-        $expression = self::MAPPINGS[$shortcut] ?? $expression;
+        $expression = self::$registeredAliases[$shortcut] ?? $expression;
 
         $this->fieldFactory = $fieldFactory ?: new FieldFactory();
         $this->setExpression($expression);
diff --git a/tests/Cron/CronExpressionTest.php b/tests/Cron/CronExpressionTest.php
index 61be75cf..6036c1d1 100644
--- a/tests/Cron/CronExpressionTest.php
+++ b/tests/Cron/CronExpressionTest.php
@@ -10,6 +10,7 @@
 use DateTimeImmutable;
 use DateTimeZone;
 use InvalidArgumentException;
+use LogicException;
 use PHPUnit\Framework\TestCase;
 use Webmozart\Assert\Assert;
 
@@ -724,4 +725,60 @@ public function testIssue128()
         $prev = $e->getPreviousRunDate(new \DateTime('2022-08-20 03:44:02'), 1);
         $this->assertEquals($expected, $prev);
     }
+
+    public function testItCanRegisterAnValidExpression(): void
+    {
+        CronExpression::registerAlias('@every', '* * * * *');
+
+        self::assertCount(8, CronExpression::getAliases());
+        self::assertArrayHasKey('@every', CronExpression::getAliases());
+        self::assertTrue(CronExpression::supportsAlias('@every'));
+        self::assertEquals(new CronExpression('@every'), new CronExpression('* * * * *'));
+
+        self::assertTrue(CronExpression::unregisterAlias('@every'));
+        self::assertFalse(CronExpression::unregisterAlias('@every'));
+
+        self::assertCount(7, CronExpression::getAliases());
+        self::assertArrayNotHasKey('@every', CronExpression::getAliases());
+        self::assertFalse(CronExpression::supportsAlias('@every'));
+
+        $this->expectException(LogicException::class);
+        new CronExpression('@every');
+    }
+
+    public function testItWillFailToRegisterAnInvalidExpression(): void
+    {
+        $this->expectException(LogicException::class);
+
+        CronExpression::registerAlias('@every', 'foobar');
+    }
+
+    public function testItWillFailToRegisterAnInvalidName(): void
+    {
+        $this->expectException(LogicException::class);
+
+        CronExpression::registerAlias('every', '* * * * *');
+    }
+
+    public function testItWillFailToRegisterAnInvalidName2(): void
+    {
+        $this->expectException(LogicException::class);
+
+        CronExpression::registerAlias('@évery', '* * * * *');
+    }
+
+    public function testItWillFailToRegisterAValidNameTwice(): void
+    {
+        CronExpression::registerAlias('@Ev_eR_y', '* * * * *');
+
+        $this->expectException(LogicException::class);
+        CronExpression::registerAlias('@eV_Er_Y', '2 2 2 2 2');
+    }
+
+    public function testItWillFailToUnregisterADefaultExpression(): void
+    {
+        $this->expectException(LogicException::class);
+
+        CronExpression::unregisterAlias('@daily');
+    }
 }