chore: major code cleanup and type safety using phpstan

tests/BusProNet/DataLoader/HotelDataLoaderTest.php

@@ -27,7 +27,7 @@ class HotelDataLoaderTest extends TestCase
 </hotels>';
 
         $filesystem = $this->createMock(FilesystemOperator::class);
-        $filesystem->expects($this->once())
+        $filesystem->expects(self::once())
             ->method('read')
             ->with('hotel.xml')
             ->willReturn($xmlContent);
@@ -37,17 +37,17 @@ class HotelDataLoaderTest extends TestCase
 
         $hotels = $loader->loadAll();
 
-        $this->assertIsArray($hotels);
-        $this->assertArrayHasKey(163113, $hotels);
+        self::assertIsArray($hotels);
+        self::assertArrayHasKey(163113, $hotels);
 
         $hotel = $hotels[163113];
-        $this->assertInstanceOf(Hotel::class, $hotel);
-        $this->assertEquals(163113, $hotel->id);
-        $this->assertEquals('L\'Oxalys', $hotel->name);
-        $this->assertEquals('SBWOXA', $hotel->code);
-        $this->assertEquals('Val Thorens', $hotel->city);
-        $this->assertEquals('F', $hotel->country);
-        $this->assertEquals('Rue des Lacs', $hotel->street);
-        $this->assertEquals('', $hotel->phone);
+        self::assertInstanceOf(Hotel::class, $hotel);
+        self::assertEquals(163113, $hotel->id);
+        self::assertEquals('L\'Oxalys', $hotel->name);
+        self::assertEquals('SBWOXA', $hotel->code);
+        self::assertEquals('Val Thorens', $hotel->city);
+        self::assertEquals('F', $hotel->country);
+        self::assertEquals('Rue des Lacs', $hotel->street);
+        self::assertEquals('', $hotel->phone);
     }
 }