Feature/Invariant system now throws user defined exceptions.

Author: othercodes

src/Traits/HasInvariants.php

@@ -5,7 +5,7 @@
 namespace ComplexHeart\Domain\Model\Traits;
 
 use ComplexHeart\Domain\Model\Exceptions\InvariantViolation;
-use Exception;
+use Throwable;
 
 /**
  * Trait HasInvariants
@@ -15,26 +15,38 @@
  */
 trait HasInvariants
 {
+    /**
+     * Static property to keep cached invariants list to optimize performance.
+     *
+     * @var array<string, <string, string>>
+     */
+    private static $_invariantsCache = [];
+
     /**
      * Retrieve the object invariants.
      *
      * @return string[]
      */
     final public static function invariants(): array
     {
-        $invariants = [];
-        foreach (get_class_methods(static::class) as $invariant) {
-            if (str_starts_with($invariant, 'invariant') && !in_array($invariant, ['invariants', 'invariantHandler'])) {
-                $invariantRuleName = preg_replace('/[A-Z]([A-Z](?![a-z]))*/', ' $0', $invariant);
-                if (is_null($invariantRuleName)) {
-                    continue;
-                }
+        if (array_key_exists(static::class, static::$_invariantsCache) === false) {
+            $invariants = [];
+            foreach (get_class_methods(static::class) as $invariant) {
+                if (str_starts_with($invariant, 'invariant') && !in_array($invariant,
+                        ['invariants', 'invariantHandler'])) {
+                    $invariantRuleName = preg_replace('/[A-Z]([A-Z](?![a-z]))*/', ' $0', $invariant);
+                    if (is_null($invariantRuleName)) {
+                        continue;
+                    }
 
-                $invariants[$invariant] = str_replace('invariant ', '', strtolower($invariantRuleName));
+                    $invariants[$invariant] = str_replace('invariant ', '', strtolower($invariantRuleName));
+                }
             }
+
+            static::$_invariantsCache[static::class] = $invariants;
         }
 
-        return $invariants;
+        return static::$_invariantsCache[static::class];
     }
 
     /**
@@ -52,53 +64,60 @@ final public static function invariants(): array
      * If exception is thrown the error message will be the exception message.
      *
      * $onFail function must have the following signature:
-     *  fn(array<string, string>) => void
+     *  fn(array<string, Throwable>) => void
      *
      * @param  string|callable  $onFail
+     * @param  string  $exception
      *
      * @return void
      */
-    private function check(string|callable $onFail = 'invariantHandler'): void
-    {
-        $violations = $this->computeInvariantViolations();
+    private function check(
+        string|callable $onFail = 'invariantHandler',
+        string $exception = InvariantViolation::class
+    ): void {
+        $violations = $this->computeInvariantViolations($exception);
         if (!empty($violations)) {
-            call_user_func_array($this->computeInvariantHandler($onFail), [$violations]);
+            call_user_func_array($this->computeInvariantHandler($onFail, $exception), [$violations]);
         }
     }
 
     /**
      * Computes the list of invariant violations.
      *
-     * @return array<string, string>
+     * @return array<string, Throwable>
      */
-    private function computeInvariantViolations(): array
+    private function computeInvariantViolations(string $exception): array
     {
         $violations = [];
         foreach (static::invariants() as $invariant => $rule) {
             try {
                 if (!$this->{$invariant}()) {
-                    $violations[$invariant] = $rule;
+                    $violations[$invariant] = new $exception($rule);
                 }
-            } catch (Exception $e) {
-                $violations[$invariant] = $e->getMessage();
+            } catch (Throwable $e) {
+                $violations[$invariant] = $e;
             }
         }
 
         return $violations;
     }
 
-    private function computeInvariantHandler(string|callable $handlerFn): callable
+    private function computeInvariantHandler(string|callable $handlerFn, string $exception): callable
     {
         if (!is_string($handlerFn)) {
             return $handlerFn;
         }
 
         return method_exists($this, $handlerFn)
-            ? function (array $violations) use ($handlerFn): void {
-                $this->{$handlerFn}($violations);
+            ? function (array $violations) use ($handlerFn, $exception): void {
+                $this->{$handlerFn}($violations, $exception);
             }
-            : function (array $violations): void {
-                throw new InvariantViolation(
+            : function (array $violations) use ($exception): void {
+                if (count($violations) === 1) {
+                    throw array_shift($violations);
+                }
+
+                throw new $exception(
                     sprintf(
                         "Unable to create %s due %s",
                         basename(str_replace('\\', '/', static::class)),

tests/ValueObjectsTest.php

@@ -55,7 +55,7 @@
         protected string $_pattern = '[a-z]';
     };
 })
-    ->throws(InvariantViolation::class)
+    ->throws(InvalidArgumentException::class)
     ->group('Unit');
 
 test('BooleanValue should create a valid BooleanValue Object.', function () {
@@ -157,10 +157,10 @@
         protected string $valueType = 'string';
     };
 
-    expect($vo)->toHaveCount(2);
-    expect($vo)->toBeIterable();
-    expect($vo->getIterator())->toBeInstanceOf(ArrayIterator::class);
-    expect($vo[0])->toEqual('one');
+    expect($vo)->toHaveCount(2)
+        ->and($vo)->toBeIterable()
+        ->and($vo->getIterator())->toBeInstanceOf(ArrayIterator::class)
+        ->and($vo[0])->toEqual('one');
 })
     ->group('Unit');
 
@@ -223,8 +223,8 @@
 test('UUIDValue should create a valid UUIDValue Object.', function () {
     $vo = UUIDValue::random();
 
-    expect($vo->is($vo))->toBeTrue();
-    expect((string) $vo)->toEqual($vo->__toString());
+    expect($vo->is($vo))->toBeTrue()
+        ->and((string) $vo)->toEqual($vo->__toString());
 })
     ->group('Unit');
 
@@ -241,10 +241,9 @@
         const TWO = 'two';
     };
 
-    expect($vo->value())->toBe('one');
-    expect($vo->value())->toBe((string) $vo);
-
-    expect($vo::getLabels()[0])->toBe('ONE');
-    expect($vo::getLabels()[1])->toBe('TWO');
+    expect($vo->value())->toBe('one')
+        ->and($vo->value())->toBe((string) $vo)
+        ->and($vo::getLabels()[0])->toBe('ONE')
+        ->and($vo::getLabels()[1])->toBe('TWO');
 })
     ->group('Unit');