ensure delta is initialized correctly

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 7.0.1 (2022-12-26)
+
+* fixed bug with incorrectly initialized delta in `bovigo\assert\predicate\equals()`
+
 ## 7.0.0 (2022-12-25)
 
 * Raised minimum required PHP version to 8.0.0

src/main/php/predicate/Equals.php

@@ -17,14 +17,8 @@
  */
 class Equals extends Predicate implements Delta
 {
-    /**
-     * @var  double
-     */
-    private $delta;
-    /**
-     * @var  string
-     */
-    private $lastFailureDiff;
+    private float $delta = 0.0;
+    private string $lastFailureDiff = '';
 
     public function __construct(private mixed $expected) { }
 
@@ -96,7 +90,7 @@ public function __toString(): string
     /**
      * checks if a diff is available for the last failure
      *
-     * @since   1.7.0
+     * @since 1.7.0
      */
     public function hasDiffForLastFailure(): bool
     {
@@ -106,7 +100,7 @@ public function hasDiffForLastFailure(): bool
     /**
      * returns diff for last failure
      *
-     * @since   1.7.0
+     * @since 1.7.0
      */
     public function diffForLastFailure(): string
     {

src/test/php/predicate/EqualsTest.php

@@ -9,7 +9,9 @@
 namespace bovigo\assert\predicate;
 
 use bovigo\assert\AssertionFailure;
+use DateTime;
 use PHPUnit\Framework\TestCase;
+use TypeError;
 
 use function bovigo\assert\assertFalse;
 use function bovigo\assert\assertThat;
@@ -151,4 +153,17 @@ public function notEqualsWithFailingDelta(): void
     {
         assertFalse(isNotEqualTo(5)->withDelta(0.1)->test(4.9));
     }
+
+    /**
+     * @test
+     * @since 7.0.1
+     * @group delta_initialized_incorrectly
+     */
+    public function deltaMustNotBeNull(): void
+    {
+        $d1 = new DateTime('1980-05-28 06:30:00 Europe/Berlin');
+        $d2 = new DateTime('@328336200');
+        expect(fn() => assertThat($d1, equals($d2)))
+            ->doesNotThrow(TypeError::class);
+    }
 }