diff --git a/core/tests/Drupal/Tests/Component/Version/ConstraintTest.php b/core/tests/Drupal/Tests/Component/Version/ConstraintTest.php
index 08edcaff96a0efd9ef5cc2a98ea893095f54c5a2..78109e573f0aab405bccde2094bacfb490a5326f 100644
--- a/core/tests/Drupal/Tests/Component/Version/ConstraintTest.php
+++ b/core/tests/Drupal/Tests/Component/Version/ConstraintTest.php
@@ -17,14 +17,14 @@ class ConstraintTest extends TestCase {
    * @covers ::isCompatible
    * @dataProvider providerIsCompatible
    */
-  public function testIsCompatible(Constraint $version_info, $current_version, $result) {
+  public function testIsCompatible(Constraint $version_info, string $current_version, bool $result): void {
     $this->assertSame($result, $version_info->isCompatible($current_version));
   }
 
   /**
    * Provider for testIsCompatible.
    */
-  public function providerIsCompatible() {
+  public static function providerIsCompatible(): array {
     $tests = [];
 
     $tests['no-dependencies'] = [new Constraint('', '8.x'), '8.1.x', TRUE];
@@ -42,8 +42,8 @@ public function providerIsCompatible() {
       '>=   1.0,  <=   2.0',
     ];
     foreach ($whitespace_variation_constraints as $whitespace_variation_constraint) {
-      $tests += $this->createTestsForVersions($whitespace_variation_constraint, ['1.0', '2.0', '1.5'], TRUE, '8.x');
-      $tests += $this->createTestsForVersions($whitespace_variation_constraint, ['0.9', '2.1'], FALSE, '8.x');
+      $tests += self::createTestsForVersions($whitespace_variation_constraint, ['1.0', '2.0', '1.5'], TRUE, '8.x');
+      $tests += self::createTestsForVersions($whitespace_variation_constraint, ['0.9', '2.1'], FALSE, '8.x');
     }
 
     // We support both '=' and '==' for the equal operator. If no operator is
@@ -62,89 +62,89 @@ public function providerIsCompatible() {
           else {
             $constraint = "< 8.x-4.x, > 8.x-1.x";
           }
-          $tests += $this->createTestsForVersions($constraint, ['4.0', '3.9', '2.1', '1.9'], FALSE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['4.0', '3.9', '2.1', '1.9'], FALSE, $core_compatibility);
 
           // Stable version. For example "=8.x-1.0".
           $constraint = "{$equal_operator} $core_compatibility-1.0";
-          $tests += $this->createTestsForVersions($constraint, ['1.0'], TRUE, $core_compatibility);
-          $tests += $this->createTestsForVersions($constraint, ['1.1', '0.9'], FALSE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['1.0'], TRUE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['1.1', '0.9'], FALSE, $core_compatibility);
 
           // Alpha version. For example "=8.x-1.1-alpha12".
           $constraint = "{$equal_operator} $core_compatibility-1.1-alpha12";
-          $tests += $this->createTestsForVersions($constraint, ['1.1-alpha12'], TRUE, $core_compatibility);
-          $tests += $this->createTestsForVersions($constraint, ['1.1-alpha10', '1.1-beta1'], FALSE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['1.1-alpha12'], TRUE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['1.1-alpha10', '1.1-beta1'], FALSE, $core_compatibility);
 
           // Beta version. For example "=8.x-1.1-beta8".
           $constraint = "{$equal_operator} $core_compatibility-1.1-beta8";
-          $tests += $this->createTestsForVersions($constraint, ['1.1-beta8'], TRUE, $core_compatibility);
-          $tests += $this->createTestsForVersions($constraint, ['1.1-beta4'], FALSE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['1.1-beta8'], TRUE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['1.1-beta4'], FALSE, $core_compatibility);
 
           // RC version. For example "=8.x-1.1-rc11".
           $constraint = "{$equal_operator} $core_compatibility-1.1-rc11";
-          $tests += $this->createTestsForVersions($constraint, ['1.1-rc11'], TRUE, $core_compatibility);
-          $tests += $this->createTestsForVersions($constraint, ['1.1-rc2'], FALSE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['1.1-rc11'], TRUE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['1.1-rc2'], FALSE, $core_compatibility);
 
           // Test greater than. For example ">8.x-1.x".
           $constraint = "> $core_compatibility-1.x";
-          $tests += $this->createTestsForVersions($constraint, ['2.0'], TRUE, $core_compatibility);
-          $tests += $this->createTestsForVersions($constraint, ['1.1', '0.9'], FALSE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['2.0'], TRUE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['1.1', '0.9'], FALSE, $core_compatibility);
 
           // Test greater than or equal ">=8.x-1.0".
-          $tests += $this->createTestsForVersions(">= $core_compatibility-1.0", ['1.1', '1.0'], TRUE, $core_compatibility);
-          $tests += $this->createTestsForVersions(">= $core_compatibility-1.1", ['1.0'], FALSE, $core_compatibility);
+          $tests += self::createTestsForVersions(">= $core_compatibility-1.0", ['1.1', '1.0'], TRUE, $core_compatibility);
+          $tests += self::createTestsForVersions(">= $core_compatibility-1.1", ['1.0'], FALSE, $core_compatibility);
 
           // Test less than. For examples"<8.x-1.1".
           $constraint = "< $core_compatibility-1.1";
-          $tests += $this->createTestsForVersions($constraint, ['1.1'], FALSE, $core_compatibility);
-          $tests += $this->createTestsForVersions($constraint, ['1.0'], TRUE, $core_compatibility);
-          $tests += $this->createTestsForVersions("< $core_compatibility-1.0", ['1.1'], FALSE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['1.1'], FALSE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['1.0'], TRUE, $core_compatibility);
+          $tests += self::createTestsForVersions("< $core_compatibility-1.0", ['1.1'], FALSE, $core_compatibility);
 
           // Test less than or equal. For example "<=8.x-1.x".
           $constraint = "<= $core_compatibility-1.x";
-          $tests += $this->createTestsForVersions($constraint, ['2.0'], FALSE, $core_compatibility);
-          $tests += $this->createTestsForVersions($constraint, ['1.9', '1.1', '0.9'], TRUE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['2.0'], FALSE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['1.9', '1.1', '0.9'], TRUE, $core_compatibility);
 
           // Test greater than and less than. For example "<8.x-4.x,>8.x-1.x".
           $constraint = "< $core_compatibility-4.x, > $core_compatibility-1.x";
-          $tests += $this->createTestsForVersions($constraint, ['4.0', '1.9'], FALSE, $core_compatibility);
-          $tests += $this->createTestsForVersions($constraint, ['3.9', '2.1'], TRUE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['4.0', '1.9'], FALSE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['3.9', '2.1'], TRUE, $core_compatibility);
 
           // Test greater than and less than with no core version in
           // constraint. For example "<4.x,>1.x".
           $constraint = "< 4.x, > 1.x";
-          $tests += $this->createTestsForVersions($constraint, ['4.0', '1.9'], FALSE, $core_compatibility);
-          $tests += $this->createTestsForVersions($constraint, ['3.9', '2.1'], TRUE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['4.0', '1.9'], FALSE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['3.9', '2.1'], TRUE, $core_compatibility);
 
           // Test greater than or equals and equals minor version. Both of
           // these conditions will pass. For example "8.x-2.x,>=2.4-alpha2".
           $constraint = "{$equal_operator} $core_compatibility-2.x, >= 2.4-alpha2";
-          $tests += $this->createTestsForVersions($constraint, ['2.4-beta3'], TRUE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['2.4-beta3'], TRUE, $core_compatibility);
 
           // Test greater than or equals and equals exact version. For example
           // "8.x-2.0,>=2.4-alpha2".
           $constraint = "{$equal_operator} $core_compatibility-2.0, >= 2.4-alpha2";
-          $tests += $this->createTestsForVersions($constraint, ['2.4-beta3'], FALSE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['2.4-beta3'], FALSE, $core_compatibility);
 
           // Test unsatisfiable greater than and less than. For example
           // "> 8.x-4.x,<8.x-1.x".
           $constraint = "> $core_compatibility-4.x, < $core_compatibility-1.x";
-          $tests += $this->createTestsForVersions($constraint, ['4.0', '3.9', '2.1', '1.9'], FALSE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['4.0', '3.9', '2.1', '1.9'], FALSE, $core_compatibility);
 
           // Test 2 equals with 1 that is compatible and 1 that is not. For
           // example "=2.x,=2.4-beta".
           $constraint = "{$equal_operator} {$core_compatibility}2.x, {$equal_operator} 2.4-beta3";
-          $tests += $this->createTestsForVersions($constraint, ['2.4-beta3'], FALSE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['2.4-beta3'], FALSE, $core_compatibility);
 
           // Test unsatisfiable multiple equals. For example
           // "8.x-2.1,8.x-2.3,\"(>1.0,<=3.2,!=3.0)-8.x.2.5".
           $constraint = "{$equal_operator} $core_compatibility-2.1, {$equal_operator} $core_compatibility-2.3,\"(> 1.0, <= 3.2, {$not_equal_operator} 3.0)-8.x.2.5";
-          $tests += $this->createTestsForVersions($constraint, ['2.1', '2.2', '2.3'], FALSE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['2.1', '2.2', '2.3'], FALSE, $core_compatibility);
 
           // Test with a range and multiple exclusions. For example
           // ">1.0,<=3.2,!=3.0,!=1.5,!=2.7".
           $constraint = "> 1.0, <= 3.2, $not_equal_operator 3.0, $not_equal_operator 1.5, $not_equal_operator 2.7";
-          $tests += $this->createTestsForVersions($constraint, ['1.1', '3.1', '2.1'], TRUE, $core_compatibility);
-          $tests += $this->createTestsForVersions($constraint, ['3.0', '1.5', '2.7', '3.3'], FALSE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['1.1', '3.1', '2.1'], TRUE, $core_compatibility);
+          $tests += self::createTestsForVersions($constraint, ['3.0', '1.5', '2.7', '3.3'], FALSE, $core_compatibility);
         }
       }
     }
@@ -171,7 +171,7 @@ public function providerIsCompatible() {
    * @return array[]
    *   The test cases to be used with ::testIsCompatible().
    */
-  private function createTestsForVersions($constraint_string, array $versions, $expected_result, $core_compatibility = '8.x') {
+  private static function createTestsForVersions(string $constraint_string, array $versions, bool $expected_result, string $core_compatibility = '8.x'): array {
     $constraint = new Constraint($constraint_string, $core_compatibility);
     $tests = [];
     foreach ($versions as $version) {