refactor(): Replace "string" to IsType::TYPE_STRING in tests

Author: alezhu

tests/Alezhu/PHPUnitArrayContainsAsserts/Constraint/ArrayContainsTest.php

@@ -4,6 +4,7 @@
 
 use Alezhu\PHPUnitArrayContainsAsserts\Constraint\ArrayContains;
 use PHPUnit\Framework\AssertionFailedError;
+use PHPUnit\Framework\Constraint\IsType;
 use PHPUnit\Framework\ExpectationFailedException;
 use PHPUnit\Framework\TestCase;
 use SebastianBergmann\Exporter\Exporter;
@@ -36,7 +37,7 @@ public function test_matches_unassoc_should_be_valid_if_all_expected_values_in_r
 
     public function test_matches_assoc_should_be_valid_if_all_expected_values_in_result()
     {
-        $instance = new ArrayContains(["foo" => self::isType("string"), "bar" => 1]);
+        $instance = new ArrayContains(["foo" => self::isType(IsType::TYPE_STRING), "bar" => 1]);
         $result = $instance->evaluate(["bar" => 1, "foo" => "value", "baz" => true], '', true);
         self::assertTrue($result);
     }
@@ -79,7 +80,7 @@ public function test_matches_assoc_should_raise_exception_if_some_of_expected_ke
     {
         $this->expectException(ExpectationFailedException::class);
         $result = ["bar" => "value"];
-        $instance = new ArrayContains(["foo" => self::isType("string"), "bar" => 1]);
+        $instance = new ArrayContains(["foo" => self::isType(IsType::TYPE_STRING), "bar" => 1]);
         $exporter = new Exporter();
         $this->expectExceptionMessage(
             sprintf(
@@ -95,7 +96,7 @@ public function test_matches_assoc_should_raise_exception_if_some_of_expected_va
     {
         $this->expectException(ExpectationFailedException::class);
         $result = ["bar" => "value", "foo" => "value"];
-        $instance = new ArrayContains(["foo" => self::isType("string"), "bar" => 1]);
+        $instance = new ArrayContains(["foo" => self::isType(IsType::TYPE_STRING), "bar" => 1]);
         $exporter = new Exporter();
         $this->expectExceptionMessage(
             sprintf(