Add geographic distance assertions

README.md

@@ -75,6 +75,12 @@ This will prevent any method name conflicts with core, your custom or other trai
     'lat' => 53.551085,
     'lng' => 9.993682,
 ]);
+
+$hamburg = ['lat' => 53.551085, 'lng' => 9.993682];
+$berlin = ['lat' => 52.520008, 'lng' => 13.404954];
+
+\Astrotomic\PhpunitAssertions\GeographicAssertions::assertDistanceGreaterThanOrEqual(255_000, $hamburg, $berlin);
+\Astrotomic\PhpunitAssertions\GeographicAssertions::assertDistanceLessThanOrEqual(256_000, $hamburg, $berlin);
 ```
 
 ### HashID

src/GeographicAssertions.php

@@ -6,6 +6,8 @@
 
 final class GeographicAssertions
 {
+    private const EARTH_RADIUS_METERS = 6_371_000;
+
     public static function assertLatitude($actual): void
     {
         PHPUnit::assertIsNumeric($actual);
@@ -28,4 +30,40 @@ public static function assertCoordinates($actual, string $lat = 'lat', string $l
         PHPUnit::assertArrayHasKey($lng, $actual);
         self::assertLongitude($actual[$lng]);
     }
+
+    public static function assertDistanceGreaterThanOrEqual(
+        int $distance,
+        $from,
+        $to,
+        string $lat = 'lat',
+        string $lng = 'lng'
+    ): void {
+        PHPUnit::assertGreaterThanOrEqual($distance, self::distance($from, $to, $lat, $lng));
+    }
+
+    public static function assertDistanceLessThanOrEqual(
+        int $distance,
+        $from,
+        $to,
+        string $lat = 'lat',
+        string $lng = 'lng'
+    ): void {
+        PHPUnit::assertLessThanOrEqual($distance, self::distance($from, $to, $lat, $lng));
+    }
+
+    private static function distance($from, $to, string $lat, string $lng): float
+    {
+        self::assertCoordinates($from, $lat, $lng);
+        self::assertCoordinates($to, $lat, $lng);
+
+        $fromLatitude = deg2rad((float) $from[$lat]);
+        $toLatitude = deg2rad((float) $to[$lat]);
+        $latitudeDelta = $toLatitude - $fromLatitude;
+        $longitudeDelta = deg2rad((float) $to[$lng] - (float) $from[$lng]);
+
+        $a = sin($latitudeDelta / 2) ** 2
+            + cos($fromLatitude) * cos($toLatitude) * sin($longitudeDelta / 2) ** 2;
+
+        return self::EARTH_RADIUS_METERS * 2 * asin(sqrt(min(1.0, $a)));
+    }
 }

tests/GeographicAssertionsTest.php

@@ -58,4 +58,46 @@ public static function it_can_validate_array_of_coordinates_with_custom_keys():
 
         GeographicAssertions::assertCoordinates($coords, $lat, $lng);
     }
+
+    /** @test */
+    public static function it_can_validate_distance_greater_than_or_equal(): void
+    {
+        $hamburg = ['lat' => 53.551085, 'lng' => 9.993682];
+        $berlin = ['lat' => 52.520008, 'lng' => 13.404954];
+
+        GeographicAssertions::assertDistanceGreaterThanOrEqual(255_000, $hamburg, $berlin);
+        GeographicAssertions::assertDistanceGreaterThanOrEqual(0, $hamburg, $hamburg);
+    }
+
+    /** @test */
+    public static function it_can_validate_distance_less_than_or_equal(): void
+    {
+        $hamburg = ['lat' => 53.551085, 'lng' => 9.993682];
+        $berlin = ['lat' => 52.520008, 'lng' => 13.404954];
+
+        GeographicAssertions::assertDistanceLessThanOrEqual(256_000, $hamburg, $berlin);
+        GeographicAssertions::assertDistanceLessThanOrEqual(0, $hamburg, $hamburg);
+    }
+
+    /** @test */
+    public static function it_can_validate_distance_with_custom_keys(): void
+    {
+        $hamburg = ['latitude' => 53.551085, 'longitude' => 9.993682];
+        $berlin = ['latitude' => 52.520008, 'longitude' => 13.404954];
+
+        GeographicAssertions::assertDistanceGreaterThanOrEqual(
+            255_000,
+            $hamburg,
+            $berlin,
+            'latitude',
+            'longitude'
+        );
+        GeographicAssertions::assertDistanceLessThanOrEqual(
+            256_000,
+            $hamburg,
+            $berlin,
+            'latitude',
+            'longitude'
+        );
+    }
 }