From 3dd6b45e891557dfe209a45332da9fd66843de4e Mon Sep 17 00:00:00 2001
From: MohammadAlhallaq <mohammad.alhallaq1@gmail.com>
Date: Sun, 21 Dec 2025 15:20:08 +0300
Subject: [PATCH 1/7] wip

---
 packages/validation/src/Rules/Custom.php      | 47 +++++++++++++++++++
 .../validation/tests/Rules/CustomTest.php     | 47 +++++++++++++++++++
 2 files changed, 94 insertions(+)
 create mode 100644 packages/validation/src/Rules/Custom.php
 create mode 100644 packages/validation/tests/Rules/CustomTest.php

diff --git a/packages/validation/src/Rules/Custom.php b/packages/validation/src/Rules/Custom.php
new file mode 100644
index 000000000..7669dc557
--- /dev/null
+++ b/packages/validation/src/Rules/Custom.php
@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tempest\Validation\Rules;
+
+use Closure;
+use Attribute;
+use InvalidArgumentException;
+use ReflectionFunction;
+use Tempest\Validation\Rule;
+
+
+/**
+ * Custom validation rule defined by a closure.
+ *
+ * The closure receives the value and must return true if it is valid, false otherwise.
+ */
+#[Attribute(Attribute::TARGET_PROPERTY | Attribute::IS_REPEATABLE)]
+final readonly class Custom implements Rule
+{
+
+    private Closure $callback;
+
+    public function __construct(
+        Closure $callback,
+    ) {
+        $this->callback = $callback;
+
+        $reflection = new ReflectionFunction($callback);
+
+        // Must be static
+        if (!$reflection->isStatic()) {
+            throw new InvalidArgumentException('Validation closures must be static');
+        }
+
+        // Must not capture variables
+        if ($reflection->getStaticVariables() !== []) {
+            throw new InvalidArgumentException('Validation closures may not capture variables.');
+        }
+    }
+
+    public function isValid(mixed $value): bool
+    {
+        return ($this->callback)($value);
+    }
+}
diff --git a/packages/validation/tests/Rules/CustomTest.php b/packages/validation/tests/Rules/CustomTest.php
new file mode 100644
index 000000000..49352ba25
--- /dev/null
+++ b/packages/validation/tests/Rules/CustomTest.php
@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tempest\Validation\Tests\Rules;
+
+use PHPUnit\Framework\TestCase;
+use Tempest\Validation\Rules\Custom;
+
+/**
+ * @internal
+ */
+final class CustomTest extends TestCase
+{
+    public function test_closure_validation_passes(): void
+    {
+        $rule = new Custom(static fn(mixed $value): bool => str_contains((string) $value, '@'));
+
+        $this->assertTrue($rule->isValid('user@example.com'));
+        $this->assertTrue($rule->isValid('test@domain.org'));
+    }
+
+    public function test_closure_validation_fails(): void
+    {
+        $rule = new Custom(static fn(mixed $value): bool => str_contains((string) $value, '@'));
+
+        $this->assertFalse($rule->isValid('username'));
+        $this->assertFalse($rule->isValid('example.com'));
+    }
+
+    public function test_non_string_value_fails(): void
+    {
+        $rule = new Custom(static fn(mixed $value): bool => str_contains((string) $value, '@'));
+
+        $this->assertFalse($rule->isValid(12345));
+        $this->assertFalse($rule->isValid(null));
+        $this->assertFalse($rule->isValid(false));
+    }
+
+    public function test_static_closure_required(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+
+        // Non-static closure should throw exception
+        new Custom(fn(mixed $value): bool => str_contains((string) $value, '@'));
+    }
+}

From 03b89a6efcfbcc1f690420476062badbcfc09832 Mon Sep 17 00:00:00 2001
From: MohammadAlhallaq <mohammad.alhallaq1@gmail.com>
Date: Sun, 21 Dec 2025 15:24:52 +0300
Subject: [PATCH 2/7] feat(validation): Validation rule based on closure

---
 packages/validation/src/Rules/Custom.php | 1 -
 1 file changed, 1 deletion(-)

diff --git a/packages/validation/src/Rules/Custom.php b/packages/validation/src/Rules/Custom.php
index 7669dc557..20a8a6549 100644
--- a/packages/validation/src/Rules/Custom.php
+++ b/packages/validation/src/Rules/Custom.php
@@ -10,7 +10,6 @@
 use ReflectionFunction;
 use Tempest\Validation\Rule;
 
-
 /**
  * Custom validation rule defined by a closure.
  *

From a8ef450e9cf85d86a063dc63ad3e80c6abda431a Mon Sep 17 00:00:00 2001
From: MohammadAlhallaq <mohammad.alhallaq1@gmail.com>
Date: Sun, 21 Dec 2025 15:30:27 +0300
Subject: [PATCH 3/7] feat(validation): validation rules based on closures

---
 packages/validation/src/Rules/Custom.php | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/validation/src/Rules/Custom.php b/packages/validation/src/Rules/Custom.php
index 20a8a6549..7669dc557 100644
--- a/packages/validation/src/Rules/Custom.php
+++ b/packages/validation/src/Rules/Custom.php
@@ -10,6 +10,7 @@
 use ReflectionFunction;
 use Tempest\Validation\Rule;
 
+
 /**
  * Custom validation rule defined by a closure.
  *

From 694e74a5475e826cd019de80de77e0fd68709fb3 Mon Sep 17 00:00:00 2001
From: MohammadAlhallaq <mohammad.alhallaq1@gmail.com>
Date: Sun, 21 Dec 2025 15:43:40 +0300
Subject: [PATCH 4/7] fix: files formatting

---
 packages/validation/src/Rules/Custom.php       |  6 ++----
 packages/validation/tests/Rules/CustomTest.php | 10 ++++------
 2 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/packages/validation/src/Rules/Custom.php b/packages/validation/src/Rules/Custom.php
index 7669dc557..759ca45a2 100644
--- a/packages/validation/src/Rules/Custom.php
+++ b/packages/validation/src/Rules/Custom.php
@@ -4,13 +4,12 @@
 
 namespace Tempest\Validation\Rules;
 
-use Closure;
 use Attribute;
+use Closure;
 use InvalidArgumentException;
 use ReflectionFunction;
 use Tempest\Validation\Rule;
 
-
 /**
  * Custom validation rule defined by a closure.
  *
@@ -19,7 +18,6 @@
 #[Attribute(Attribute::TARGET_PROPERTY | Attribute::IS_REPEATABLE)]
 final readonly class Custom implements Rule
 {
-
     private Closure $callback;
 
     public function __construct(
@@ -30,7 +28,7 @@ public function __construct(
         $reflection = new ReflectionFunction($callback);
 
         // Must be static
-        if (!$reflection->isStatic()) {
+        if (! $reflection->isStatic()) {
             throw new InvalidArgumentException('Validation closures must be static');
         }
 
diff --git a/packages/validation/tests/Rules/CustomTest.php b/packages/validation/tests/Rules/CustomTest.php
index 49352ba25..0ca6ce480 100644
--- a/packages/validation/tests/Rules/CustomTest.php
+++ b/packages/validation/tests/Rules/CustomTest.php
@@ -14,15 +14,14 @@ final class CustomTest extends TestCase
 {
     public function test_closure_validation_passes(): void
     {
-        $rule = new Custom(static fn(mixed $value): bool => str_contains((string) $value, '@'));
-
+        $rule = new Custom(static fn (mixed $value): bool => str_contains((string) $value, '@'));
         $this->assertTrue($rule->isValid('user@example.com'));
         $this->assertTrue($rule->isValid('test@domain.org'));
     }
 
     public function test_closure_validation_fails(): void
     {
-        $rule = new Custom(static fn(mixed $value): bool => str_contains((string) $value, '@'));
+        $rule = new Custom(static fn (mixed $value): bool => str_contains((string) $value, '@'));
 
         $this->assertFalse($rule->isValid('username'));
         $this->assertFalse($rule->isValid('example.com'));
@@ -30,7 +29,7 @@ public function test_closure_validation_fails(): void
 
     public function test_non_string_value_fails(): void
     {
-        $rule = new Custom(static fn(mixed $value): bool => str_contains((string) $value, '@'));
+        $rule = new Custom(static fn (mixed $value): bool => str_contains((string) $value, '@'));
 
         $this->assertFalse($rule->isValid(12345));
         $this->assertFalse($rule->isValid(null));
@@ -41,7 +40,6 @@ public function test_static_closure_required(): void
     {
         $this->expectException(\InvalidArgumentException::class);
 
-        // Non-static closure should throw exception
-        new Custom(fn(mixed $value): bool => str_contains((string) $value, '@'));
+        new Custom(fn (mixed $value): bool => str_contains((string) $value, '@'));
     }
 }

From 30d35bd0b9470b85cab0b094a9d4c7b2b19d58c6 Mon Sep 17 00:00:00 2001
From: MohammadAlhallaq <mohammad.alhallaq1@gmail.com>
Date: Sun, 21 Dec 2025 16:48:09 +0300
Subject: [PATCH 5/7] fix: more descriptive class name

---
 .../validation/src/Rules/{Custom.php => Closure.php} |  7 +++----
 .../tests/Rules/{CustomTest.php => ClosureTest.php}  | 12 ++++++------
 2 files changed, 9 insertions(+), 10 deletions(-)
 rename packages/validation/src/Rules/{Custom.php => Closure.php} (89%)
 rename packages/validation/tests/Rules/{CustomTest.php => ClosureTest.php} (65%)

diff --git a/packages/validation/src/Rules/Custom.php b/packages/validation/src/Rules/Closure.php
similarity index 89%
rename from packages/validation/src/Rules/Custom.php
rename to packages/validation/src/Rules/Closure.php
index 759ca45a2..cd6d60fd0 100644
--- a/packages/validation/src/Rules/Custom.php
+++ b/packages/validation/src/Rules/Closure.php
@@ -5,7 +5,6 @@
 namespace Tempest\Validation\Rules;
 
 use Attribute;
-use Closure;
 use InvalidArgumentException;
 use ReflectionFunction;
 use Tempest\Validation\Rule;
@@ -16,12 +15,12 @@
  * The closure receives the value and must return true if it is valid, false otherwise.
  */
 #[Attribute(Attribute::TARGET_PROPERTY | Attribute::IS_REPEATABLE)]
-final readonly class Custom implements Rule
+final readonly class Closure implements Rule
 {
-    private Closure $callback;
+    private \Closure $callback;
 
     public function __construct(
-        Closure $callback,
+        \Closure $callback,
     ) {
         $this->callback = $callback;
 
diff --git a/packages/validation/tests/Rules/CustomTest.php b/packages/validation/tests/Rules/ClosureTest.php
similarity index 65%
rename from packages/validation/tests/Rules/CustomTest.php
rename to packages/validation/tests/Rules/ClosureTest.php
index 0ca6ce480..ea81e9c0e 100644
--- a/packages/validation/tests/Rules/CustomTest.php
+++ b/packages/validation/tests/Rules/ClosureTest.php
@@ -5,23 +5,23 @@
 namespace Tempest\Validation\Tests\Rules;
 
 use PHPUnit\Framework\TestCase;
-use Tempest\Validation\Rules\Custom;
+use Tempest\Validation\Rules\Closure;
 
 /**
  * @internal
  */
-final class CustomTest extends TestCase
+final class ClosureTest extends TestCase
 {
     public function test_closure_validation_passes(): void
     {
-        $rule = new Custom(static fn (mixed $value): bool => str_contains((string) $value, '@'));
+        $rule = new Closure(static fn (mixed $value): bool => str_contains((string) $value, '@'));
         $this->assertTrue($rule->isValid('user@example.com'));
         $this->assertTrue($rule->isValid('test@domain.org'));
     }
 
     public function test_closure_validation_fails(): void
     {
-        $rule = new Custom(static fn (mixed $value): bool => str_contains((string) $value, '@'));
+        $rule = new Closure(static fn (mixed $value): bool => str_contains((string) $value, '@'));
 
         $this->assertFalse($rule->isValid('username'));
         $this->assertFalse($rule->isValid('example.com'));
@@ -29,7 +29,7 @@ public function test_closure_validation_fails(): void
 
     public function test_non_string_value_fails(): void
     {
-        $rule = new Custom(static fn (mixed $value): bool => str_contains((string) $value, '@'));
+        $rule = new Closure(static fn (mixed $value): bool => str_contains((string) $value, '@'));
 
         $this->assertFalse($rule->isValid(12345));
         $this->assertFalse($rule->isValid(null));
@@ -40,6 +40,6 @@ public function test_static_closure_required(): void
     {
         $this->expectException(\InvalidArgumentException::class);
 
-        new Custom(fn (mixed $value): bool => str_contains((string) $value, '@'));
+        new Closure(fn (mixed $value): bool => str_contains((string) $value, '@'));
     }
 }

From cd1aeb4e2db51ee1b302c156a5a2c49b9fe6a7ad Mon Sep 17 00:00:00 2001
From: MohammadAlhallaq <mohammad.alhallaq1@gmail.com>
Date: Wed, 31 Dec 2025 01:39:03 +0300
Subject: [PATCH 6/7] refactor: additional test case

---
 .../src/Rules/{Closure.php => Predicate.php}  |  7 ++-
 .../ObjectWithPredicateValidation.php         | 15 +++++
 .../validation/tests/Rules/ClosureTest.php    | 45 --------------
 .../validation/tests/Rules/PredicateTest.php  | 59 +++++++++++++++++++
 4 files changed, 78 insertions(+), 48 deletions(-)
 rename packages/validation/src/Rules/{Closure.php => Predicate.php} (89%)
 create mode 100644 packages/validation/tests/Fixtures/ObjectWithPredicateValidation.php
 delete mode 100644 packages/validation/tests/Rules/ClosureTest.php
 create mode 100644 packages/validation/tests/Rules/PredicateTest.php

diff --git a/packages/validation/src/Rules/Closure.php b/packages/validation/src/Rules/Predicate.php
similarity index 89%
rename from packages/validation/src/Rules/Closure.php
rename to packages/validation/src/Rules/Predicate.php
index cd6d60fd0..3173ca696 100644
--- a/packages/validation/src/Rules/Closure.php
+++ b/packages/validation/src/Rules/Predicate.php
@@ -5,6 +5,7 @@
 namespace Tempest\Validation\Rules;
 
 use Attribute;
+use Closure;
 use InvalidArgumentException;
 use ReflectionFunction;
 use Tempest\Validation\Rule;
@@ -15,12 +16,12 @@
  * The closure receives the value and must return true if it is valid, false otherwise.
  */
 #[Attribute(Attribute::TARGET_PROPERTY | Attribute::IS_REPEATABLE)]
-final readonly class Closure implements Rule
+final readonly class Predicate implements Rule
 {
-    private \Closure $callback;
+    private Closure $callback;
 
     public function __construct(
-        \Closure $callback,
+        Closure $callback,
     ) {
         $this->callback = $callback;
 
diff --git a/packages/validation/tests/Fixtures/ObjectWithPredicateValidation.php b/packages/validation/tests/Fixtures/ObjectWithPredicateValidation.php
new file mode 100644
index 000000000..d40f8f98d
--- /dev/null
+++ b/packages/validation/tests/Fixtures/ObjectWithPredicateValidation.php
@@ -0,0 +1,15 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tempest\Validation\Tests\Fixtures;
+
+use Tempest\Validation\Rules\Predicate;
+
+final class ObjectWithPredicateValidation
+{
+    #[Predicate(static function (string $value): bool {
+        return str_contains((string) $value, '@');
+    })]
+    public string $prop;
+}
diff --git a/packages/validation/tests/Rules/ClosureTest.php b/packages/validation/tests/Rules/ClosureTest.php
deleted file mode 100644
index ea81e9c0e..000000000
--- a/packages/validation/tests/Rules/ClosureTest.php
+++ /dev/null
@@ -1,45 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Tempest\Validation\Tests\Rules;
-
-use PHPUnit\Framework\TestCase;
-use Tempest\Validation\Rules\Closure;
-
-/**
- * @internal
- */
-final class ClosureTest extends TestCase
-{
-    public function test_closure_validation_passes(): void
-    {
-        $rule = new Closure(static fn (mixed $value): bool => str_contains((string) $value, '@'));
-        $this->assertTrue($rule->isValid('user@example.com'));
-        $this->assertTrue($rule->isValid('test@domain.org'));
-    }
-
-    public function test_closure_validation_fails(): void
-    {
-        $rule = new Closure(static fn (mixed $value): bool => str_contains((string) $value, '@'));
-
-        $this->assertFalse($rule->isValid('username'));
-        $this->assertFalse($rule->isValid('example.com'));
-    }
-
-    public function test_non_string_value_fails(): void
-    {
-        $rule = new Closure(static fn (mixed $value): bool => str_contains((string) $value, '@'));
-
-        $this->assertFalse($rule->isValid(12345));
-        $this->assertFalse($rule->isValid(null));
-        $this->assertFalse($rule->isValid(false));
-    }
-
-    public function test_static_closure_required(): void
-    {
-        $this->expectException(\InvalidArgumentException::class);
-
-        new Closure(fn (mixed $value): bool => str_contains((string) $value, '@'));
-    }
-}
diff --git a/packages/validation/tests/Rules/PredicateTest.php b/packages/validation/tests/Rules/PredicateTest.php
new file mode 100644
index 000000000..aa531ca5b
--- /dev/null
+++ b/packages/validation/tests/Rules/PredicateTest.php
@@ -0,0 +1,59 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tempest\Validation\Tests\Rules;
+
+use PHPUnit\Framework\TestCase;
+use ReflectionProperty;
+use Tempest\Validation\Rules\Predicate;
+use Tempest\Validation\Tests\Fixtures\ObjectWithPredicateValidation;
+
+/**
+ * @internal
+ */
+final class PredicateTest extends TestCase
+{
+    public function test_predicate_attribute_on_property_is_applied()
+    {
+        $reflection = new ReflectionProperty(ObjectWithPredicateValidation::class, 'prop');
+        $attributes = $reflection->getAttributes(Predicate::class);
+
+        $this->assertCount(1, $attributes);
+
+        $rule = $attributes[0]->newInstance();
+        $this->assertTrue($rule->isValid('user@example'));
+        $this->assertFalse($rule->isValid('invalid-prop'));
+    }
+
+    public function test_closure_validation_passes(): void
+    {
+        $rule = new Predicate(static fn (mixed $value): bool => str_contains((string) $value, '@'));
+        $this->assertTrue($rule->isValid('user@example.com'));
+        $this->assertTrue($rule->isValid('test@domain.org'));
+    }
+
+    public function test_closure_validation_fails(): void
+    {
+        $rule = new Predicate(static fn (mixed $value): bool => str_contains((string) $value, '@'));
+
+        $this->assertFalse($rule->isValid('username'));
+        $this->assertFalse($rule->isValid('example.com'));
+    }
+
+    public function test_non_string_value_fails(): void
+    {
+        $rule = new Predicate(static fn (mixed $value): bool => str_contains((string) $value, '@'));
+
+        $this->assertFalse($rule->isValid(12345));
+        $this->assertFalse($rule->isValid(null));
+        $this->assertFalse($rule->isValid(false));
+    }
+
+    public function test_static_closure_required(): void
+    {
+        $this->expectException(\InvalidArgumentException::class);
+
+        new Predicate(fn (mixed $value): bool => str_contains((string) $value, '@'));
+    }
+}

From 15dddce64deab771c76ae4b2c9e5fbba5b6f5c73 Mon Sep 17 00:00:00 2001
From: MohammadAlhallaq <mohammad.alhallaq1@gmail.com>
Date: Wed, 31 Dec 2025 01:43:21 +0300
Subject: [PATCH 7/7] refactor: adding return type

---
 packages/validation/tests/Rules/PredicateTest.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/validation/tests/Rules/PredicateTest.php b/packages/validation/tests/Rules/PredicateTest.php
index aa531ca5b..ea9a0360d 100644
--- a/packages/validation/tests/Rules/PredicateTest.php
+++ b/packages/validation/tests/Rules/PredicateTest.php
@@ -14,7 +14,7 @@
  */
 final class PredicateTest extends TestCase
 {
-    public function test_predicate_attribute_on_property_is_applied()
+    public function test_predicate_attribute_on_property_is_applied(): void
     {
         $reflection = new ReflectionProperty(ObjectWithPredicateValidation::class, 'prop');
         $attributes = $reflection->getAttributes(Predicate::class);