Keep driver tap callbacks separate

README.md

@@ -344,6 +344,8 @@ Schedule::driver('custom', CustomSchedule::class);
 
 Each driver exposes a static `tap` method to configure the underlying library instance before it's used:
 
+Callbacks are scoped to the concrete driver class. Configuring or clearing one driver's callback does not affect other drivers or subclasses.
+
 ```php
 use Cron\CronExpression;
 use DirectoryTree\Cadence\Drivers\CronSchedule;

src/Drivers/CronSchedule.php

@@ -15,8 +15,8 @@ protected function resolveNextOccurrence(CarbonInterface $after): ?CarbonInterfa
     {
         $cron = new CronExpression($this->expression);
 
-        if (static::$tapUsing) {
-            (static::$tapUsing)($cron, $this);
+        if ($callback = static::$tapCallbacks[static::class] ?? null) {
+            $callback($cron, $this);
         }
 
         return Carbon::instance($cron->getNextRunDate($after));

src/Drivers/RecurrSchedule.php

@@ -36,8 +36,8 @@ protected function resolveNextOccurrence(CarbonInterface $after): ?CarbonInterfa
 
         $transformer = $this->newTransformer();
 
-        if (static::$tapUsing) {
-            (static::$tapUsing)($rule, $transformer, $this);
+        if ($callback = static::$tapCallbacks[static::class] ?? null) {
+            $callback($rule, $transformer, $this);
         }
 
         $recurrences = $transformer->transform($rule, $this->newConstraint($after, $rule), false);

src/Drivers/RruleSchedule.php

@@ -30,8 +30,8 @@ protected function resolveNextOccurrence(CarbonInterface $after): ?CarbonInterfa
     {
         $rrule = new RRule($this->toRfcString());
 
-        if (static::$tapUsing) {
-            (static::$tapUsing)($rrule);
+        if ($callback = static::$tapCallbacks[static::class] ?? null) {
+            $callback($rrule);
         }
 
         $occurrences = $rrule->getOccurrencesAfter($after, false, 1);

src/Drivers/Schedule.php

@@ -18,9 +18,11 @@ abstract class Schedule implements ScheduleDriver
     protected ?string $timezone = null;
 
     /**
-     * The tap callback for configuring the underlying implementation.
+     * The tap callbacks for configuring each driver's underlying implementation.
+     *
+     * @var array<class-string, Closure>
      */
-    protected static ?Closure $tapUsing = null;
+    protected static array $tapCallbacks = [];
 
     /**
      * Create a new schedule instance.
@@ -36,7 +38,11 @@ public function __construct(string $expression, ?string $timezone = null)
      */
     public static function tap(?Closure $callback): void
     {
-        static::$tapUsing = $callback;
+        if ($callback === null) {
+            unset(static::$tapCallbacks[static::class]);
+        } else {
+            static::$tapCallbacks[static::class] = $callback;
+        }
     }
 
     /**

tests/Drivers/DriverTapTest.php

@@ -0,0 +1,104 @@
+<?php
+
+use Carbon\Carbon;
+use Cron\CronExpression;
+use DirectoryTree\Cadence\Drivers\CronSchedule;
+use DirectoryTree\Cadence\Drivers\RecurrSchedule;
+use DirectoryTree\Cadence\Drivers\RruleSchedule;
+use Recurr\Rule;
+use Recurr\Transformer\ArrayTransformer;
+use RRule\RRule;
+
+afterEach(function () {
+    CronSchedule::tap(null);
+    RruleSchedule::tap(null);
+    RecurrSchedule::tap(null);
+});
+
+it('keeps typed callbacks registered for all drivers', function () {
+    Carbon::setTestNow('2026-05-02 08:00:00');
+    $called = [];
+
+    CronSchedule::tap(function (CronExpression $cron, CronSchedule $driver) use (&$called) {
+        $called[] = $driver::class;
+    });
+
+    RruleSchedule::tap(function (RRule $rule) use (&$called) {
+        $called[] = RruleSchedule::class;
+    });
+
+    RecurrSchedule::tap(function (Rule $rule, ArrayTransformer $transformer, RecurrSchedule $driver) use (&$called) {
+        $called[] = $driver::class;
+    });
+
+    (new CronSchedule('0 9 * * *'))->getNextOccurrence(now());
+    (new RruleSchedule('FREQ=DAILY;DTSTART=20260501T090000'))->getNextOccurrence(now());
+    (new RecurrSchedule('FREQ=DAILY;DTSTART=20260501T090000'))->getNextOccurrence(now());
+
+    expect($called)->toBe([CronSchedule::class, RruleSchedule::class, RecurrSchedule::class]);
+});
+
+it('does not invoke a callback registered for another driver', function () {
+    Carbon::setTestNow('2026-05-02 08:00:00');
+    $called = false;
+
+    RecurrSchedule::tap(function (Rule $rule, ArrayTransformer $transformer) use (&$called) {
+        $called = true;
+    });
+
+    (new CronSchedule('0 9 * * *'))->getNextOccurrence(now());
+    (new RruleSchedule('FREQ=DAILY;DTSTART=20260501T090000'))->getNextOccurrence(now());
+
+    expect($called)->toBeFalse();
+});
+
+it('clears only the callback for the requested driver', function ($cleared) {
+    Carbon::setTestNow('2026-05-02 08:00:00');
+    $called = [];
+    $drivers = [
+        new CronSchedule('0 9 * * *'),
+        new RruleSchedule('FREQ=DAILY;DTSTART=20260501T090000'),
+        new RecurrSchedule('FREQ=DAILY;DTSTART=20260501T090000'),
+    ];
+
+    foreach ($drivers as $driver) {
+        $driver::tap(function () use (&$called, $driver) {
+            $called[] = $driver::class;
+        });
+    }
+
+    $cleared::tap(null);
+
+    foreach ($drivers as $driver) {
+        $driver->getNextOccurrence(now());
+    }
+
+    expect($called)->toBe(array_values(array_diff([
+        CronSchedule::class, RruleSchedule::class, RecurrSchedule::class,
+    ], [$cleared])));
+})->with([CronSchedule::class, RruleSchedule::class, RecurrSchedule::class]);
+
+it('keeps subclass callbacks separate from their parent driver', function () {
+    Carbon::setTestNow('2026-05-02 08:00:00');
+    $called = [];
+    $custom = new class('0 9 * * *') extends CronSchedule {};
+
+    CronSchedule::tap(function (CronExpression $cron, CronSchedule $driver) use (&$called) {
+        $called[] = $driver::class;
+    });
+
+    $custom::tap(function (CronExpression $cron, CronSchedule $driver) use (&$called) {
+        $called[] = $driver::class;
+    });
+
+    try {
+        (new CronSchedule('0 9 * * *'))->getNextOccurrence(now());
+        $custom->getNextOccurrence(now());
+        $custom::tap(null);
+        (new CronSchedule('0 9 * * *'))->getNextOccurrence(now());
+
+        expect($called)->toBe([CronSchedule::class, $custom::class, CronSchedule::class]);
+    } finally {
+        $custom::tap(null);
+    }
+});