diff --git a/.github/actions/setup-php-composer/action.yml b/.github/actions/setup-php-composer/action.yml
index 39cf403..e91d9b1 100644
--- a/.github/actions/setup-php-composer/action.yml
+++ b/.github/actions/setup-php-composer/action.yml
@@ -5,7 +5,7 @@ inputs:
   php-version:
     description: 'PHP version to use'
     required: false
-    default: '8.3'
+    default: '8.4'
   coverage:
     description: 'Coverage driver to use (none, xdebug, pcov)'
     required: false
diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index b3d8e08..13af43a 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -14,10 +14,10 @@ jobs:
   test:
     runs-on: ${{ matrix.os }}
     strategy:
-      fail-fast: true
+      fail-fast: false
       matrix:
         os: [ubuntu-latest, windows-latest]
-        php: [8.3, 8.4, 8.5]
+        php: [8.4, 8.5]
         stability: [prefer-lowest, prefer-stable]
 
     name: PHP${{ matrix.php }} - ${{ matrix.stability }} - ${{ matrix.os }}
diff --git a/README.md b/README.md
index cf7c604..7e92f9a 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ A modern, fluent builder for [OpenAPI 3.1](https://spec.openapis.org/oas/v3.1.0)
 
 ## Requirements
 
-- PHP 8.3+
+- PHP 8.4+
 
 ## Installation
 
diff --git a/composer.json b/composer.json
index 6a39d87..fe5f565 100644
--- a/composer.json
+++ b/composer.json
@@ -20,19 +20,22 @@
         }
     ],
     "require": {
-        "php": "^8.3",
+        "php": "^8.4",
         "ext-json": "*",
         "cortexphp/json-schema": "^1.1",
         "opis/json-schema": "^2.4"
     },
     "require-dev": {
-        "pestphp/pest": "^4.1.4",
-        "pestphp/pest-plugin-type-coverage": "^4.0.3",
+        "pestphp/pest": "^5.0",
+        "pestphp/pest-plugin-mutate": "^5.0.1",
+        "pestphp/pest-plugin-phpstan": "^5.0",
+        "pestphp/pest-plugin-rector": "^5.0",
+        "pestphp/pest-plugin-type-coverage": "^5.0",
         "phpstan/phpstan": "^2.1.32",
         "phpstan/phpstan-strict-rules": "^2.0",
         "rector/rector": "^2.2",
         "symfony/yaml": "^6.0 || ^7.0",
-        "symplify/easy-coding-standard": "13.2.3"
+        "symplify/easy-coding-standard": "~13.1.0"
     },
     "suggest": {
         "symfony/yaml": "Required for OpenApi::toYaml() output (^6.0 || ^7.0)."
@@ -51,7 +54,7 @@
         ]
     },
     "scripts": {
-        "test": "pest --no-coverage",
+        "test": "pest --parallel",
         "ecs": "ecs check --fix",
         "ecs:check": "ecs check",
         "rector": "rector process",
diff --git a/docs/openapi/installation.mdx b/docs/openapi/installation.mdx
index c471221..fbf0d92 100644
--- a/docs/openapi/installation.mdx
+++ b/docs/openapi/installation.mdx
@@ -6,7 +6,7 @@ icon: 'terminal'
 
 ## Requirements
 
-- PHP 8.3+
+- PHP 8.4+
 
 ## Installation
 
diff --git a/docs/openapi/introduction.mdx b/docs/openapi/introduction.mdx
index 206da65..97b562f 100644
--- a/docs/openapi/introduction.mdx
+++ b/docs/openapi/introduction.mdx
@@ -66,7 +66,7 @@ OpenAPI 3.1 aligns fully with **JSON Schema 2020-12**, which means every schema
     title="Type Safety"
     icon="shield"
   >
-    Built with PHP 8.3+ strict types, backed enums, and named constructors. PHPStan level 10 clean with 100% type coverage.
+    Built with PHP 8.4+ strict types, backed enums, and named constructors. PHPStan level 10 clean with 100% type coverage.
   </Card>
 </CardGroup>
 
@@ -130,7 +130,7 @@ echo $doc->toJson(JSON_PRETTY_PRINT);
 ```
 
 <Note>
-This package requires PHP 8.3 or higher. `symfony/yaml` is an optional runtime dependency — only needed if you call `toYaml()`.
+This package requires PHP 8.4 or higher. `symfony/yaml` is an optional runtime dependency — only needed if you call `toYaml()`.
 </Note>
 
 ## How It Relates to cortexphp/json-schema
diff --git a/ecs.php b/ecs.php
index 49dd243..f3e2bd1 100644
--- a/ecs.php
+++ b/ecs.php
@@ -33,7 +33,7 @@
         cleanCode: true,
     )
     ->withPhpCsFixerSets(
-        php83Migration: true,
+        php84Migration: true,
     )
     ->withRules([
         NotOperatorWithSuccessorSpaceFixer::class,
diff --git a/phpstan.dist.neon b/phpstan.dist.neon
index 2d71067..c6ff3f2 100644
--- a/phpstan.dist.neon
+++ b/phpstan.dist.neon
@@ -1,11 +1,11 @@
 includes:
   - vendor/phpstan/phpstan-strict-rules/rules.neon
+  - vendor/pestphp/pest-plugin-phpstan/extension.neon
 
 parameters:
   level: 10
   paths:
     - src
-  stubFiles:
-    - tests/phpstan/pest-expectations.stub
+    - tests
   tmpDir: .phpstan-cache
   checkBenevolentUnionTypes: true
diff --git a/rector.php b/rector.php
index 9e47c24..2dd2e5a 100644
--- a/rector.php
+++ b/rector.php
@@ -3,6 +3,7 @@
 declare(strict_types=1);
 
 use Rector\Config\RectorConfig;
+use Pest\Rector\Set\PestSetList;
 use Rector\CodeQuality\Rector\Catch_\ThrowWithPreviousExceptionRector;
 
 return RectorConfig::configure()
@@ -15,7 +16,12 @@
         importDocBlockNames: false,
         removeUnusedImports: true,
     )
-    ->withPhpSets()
+    ->withPhpSets(
+        php84: true,
+    )
+    ->withSets([
+        PestSetList::CODING_STYLE,
+    ])
     ->withPreparedSets(
         deadCode: true,
         codeQuality: true,
diff --git a/src/Concerns/BuildsArray.php b/src/Concerns/BuildsArray.php
index 4bb6493..381230b 100644
--- a/src/Concerns/BuildsArray.php
+++ b/src/Concerns/BuildsArray.php
@@ -47,12 +47,12 @@ protected function buildArray(array $fields, array $alwaysInclude = []): array
         }
 
         if ($this instanceof HasExtensionsInterface) {
-            foreach ($this->getExtensions() as $extensionKey => $extensionValue) {
-                $output[$extensionKey] = $extensionValue;
+            foreach ($this->getExtensions() as $extensionKey => $extensionValue) { // @phpstan-ignore foreach.nonIterable
+                $output[$extensionKey] = $extensionValue; // @phpstan-ignore offsetAccess.invalidOffset
             }
         }
 
-        return $output;
+        return $output; // @phpstan-ignore return.type
     }
 
     private function unwrapValue(mixed $value): mixed
diff --git a/src/OpenApi.php b/src/OpenApi.php
index 43de68b..5320230 100644
--- a/src/OpenApi.php
+++ b/src/OpenApi.php
@@ -275,7 +275,7 @@ public function validate(): void
                 return;
             }
 
-            $formatted = (new ErrorFormatter())->format($error);
+            $formatted = new ErrorFormatter()->format($error);
 
             throw new ValidationException(
                 'OpenAPI document failed meta-schema validation: ' . json_encode($formatted, JSON_UNESCAPED_SLASHES),
diff --git a/tests/Expectations.php b/tests/Expectations.php
index 501f0c5..3de7e13 100644
--- a/tests/Expectations.php
+++ b/tests/Expectations.php
@@ -3,19 +3,59 @@
 declare(strict_types=1);
 
 use Cortex\OpenApi\OpenApi;
+use PHPUnit\Framework\Assert;
 use Cortex\OpenApi\Exceptions\ValidationException;
 
 /**
- * Custom Pest expectations for OpenAPI meta-schema validation.
- * Method signatures for IDE/static analysis: tests/phpstan/pest-expectations.stub
- *
+ * @return array<mixed>
+ */
+function expectArray(mixed $value): array
+{
+    expect($value)->toBeArray();
+
+    if (! is_array($value)) {
+        Assert::fail('Expected array.');
+    }
+
+    return $value;
+}
+
+/**
+ * @param array<int, int|string> $keys
+ */
+function keyIndex(array $keys, string $key): int
+{
+    $index = array_search($key, $keys, true);
+    expect($index)->toBeInt();
+
+    if (! is_int($index)) {
+        Assert::fail("Expected key [{$key}] to exist.");
+    }
+
+    return $index;
+}
+
+function assertOpenApiValidationPasses(OpenApi $openApi): void
+{
+    try {
+        $openApi->validate();
+    } catch (ValidationException $validationException) {
+        Assert::fail(
+            'Expected OpenAPI document to pass validation: ' . $validationException->getMessage(),
+        );
+    }
+
+    Assert::assertInstanceOf(OpenApi::class, $openApi);
+}
+
+/**
  * @param array<string, list<string>> $expectedErrors
  */
 function assertOpenApiValidationErrors(OpenApi $openApi, array $expectedErrors): void
 {
     try {
         $openApi->validate();
-        test()->fail('Expected ValidationException');
+        Assert::fail('Expected ValidationException');
     } catch (ValidationException $validationException) {
         foreach ($expectedErrors as $pointer => $messages) {
             expect($validationException->errors())->toHaveKey($pointer);
@@ -26,42 +66,9 @@ function assertOpenApiValidationErrors(OpenApi $openApi, array $expectedErrors):
     }
 }
 
-expect()->extend('toFailOpenApiValidation', function (array $expectedErrors): mixed {
-    if (! $this->value instanceof OpenApi) {
-        test()->fail('Expected an OpenApi instance.');
-    }
-
-    assertOpenApiValidationErrors($this->value, $expectedErrors);
-
-    return $this;
-});
-
-expect()->extend('toFailOpenApiValidationAt', function (string $pointer, string $message): mixed {
-    if (! $this->value instanceof OpenApi) {
-        test()->fail('Expected an OpenApi instance.');
-    }
-
-    assertOpenApiValidationErrors($this->value, [
+function assertOpenApiValidationFailsAt(OpenApi $openApi, string $pointer, string $message): void
+{
+    assertOpenApiValidationErrors($openApi, [
         $pointer => [$message],
     ]);
-
-    return $this;
-});
-
-expect()->extend('toPassOpenApiValidation', function (): mixed {
-    if (! $this->value instanceof OpenApi) {
-        test()->fail('Expected an OpenApi instance.');
-    }
-
-    try {
-        $this->value->validate();
-    } catch (ValidationException $validationException) {
-        test()->fail(
-            'Expected OpenAPI document to pass validation: ' . $validationException->getMessage(),
-        );
-    }
-
-    expect($this->value)->toBeInstanceOf(OpenApi::class);
-
-    return $this;
-});
+}
diff --git a/tests/Pest.php b/tests/Pest.php
index 5802c47..cbe5884 100644
--- a/tests/Pest.php
+++ b/tests/Pest.php
@@ -4,4 +4,6 @@
 
 namespace Cortex\OpenApi\Tests;
 
-uses(TestCase::class)->in('Unit');
+pest()
+    ->extend(TestCase::class)
+    ->in('Unit');
diff --git a/tests/Unit/Concerns/BuildsArrayTest.php b/tests/Unit/Concerns/BuildsArrayTest.php
index af193cf..13732f4 100644
--- a/tests/Unit/Concerns/BuildsArrayTest.php
+++ b/tests/Unit/Concerns/BuildsArrayTest.php
@@ -55,7 +55,7 @@ public function assemble(array $fields): array
 }
 
 it('drops null fields', function (): void {
-    $out = (new BuildsArrayFixture())->assemble([
+    $out = new BuildsArrayFixture()->assemble([
         'title' => 'X',
         'version' => null,
     ]);
@@ -66,7 +66,7 @@ public function assemble(array $fields): array
 });
 
 it('drops empty arrays', function (): void {
-    $out = (new BuildsArrayFixture())->assemble([
+    $out = new BuildsArrayFixture()->assemble([
         'title' => 'X',
         'tags' => [],
     ]);
@@ -77,7 +77,7 @@ public function assemble(array $fields): array
 });
 
 it('unwraps a Serializable child', function (): void {
-    $out = (new BuildsArrayFixture())->assemble([
+    $out = new BuildsArrayFixture()->assemble([
         'info' => new BuildsArraySerializableFixture(),
     ]);
 
@@ -89,7 +89,7 @@ public function assemble(array $fields): array
 });
 
 it('unwraps a list of Serializable children preserving list semantics', function (): void {
-    $out = (new BuildsArrayFixture())->assemble([
+    $out = new BuildsArrayFixture()->assemble([
         'tags' => [
             new BuildsArraySerializableFixture(),
             new BuildsArraySerializableFixture(),
@@ -109,7 +109,7 @@ public function assemble(array $fields): array
 });
 
 it('unwraps an associative array of Serializable children preserving keys', function (): void {
-    $out = (new BuildsArrayFixture())->assemble([
+    $out = new BuildsArrayFixture()->assemble([
         'paths' => [
             '/users' => new BuildsArraySerializableFixture(),
             '/pets' => new BuildsArraySerializableFixture(),
@@ -143,7 +143,7 @@ public function assemble(array $fields): array
 });
 
 it('preserves explicit false values', function (): void {
-    $out = (new BuildsArrayFixture())->assemble([
+    $out = new BuildsArrayFixture()->assemble([
         'deprecated' => false,
     ]);
 
@@ -153,7 +153,7 @@ public function assemble(array $fields): array
 });
 
 it('preserves explicit zero values', function (): void {
-    $out = (new BuildsArrayFixture())->assemble([
+    $out = new BuildsArrayFixture()->assemble([
         'minimum' => 0,
     ]);
 
@@ -181,10 +181,10 @@ public function assemble(array $fields): array
 
     // Reference: stand-alone toArray() would include both $schema URI and title.
     $standalone = $stringSchema->toArray();
-    expect($standalone)->toHaveKey('$schema');
-    expect($standalone)->toHaveKey('title', 'IgnoredTitle');
+    expect($standalone)->toHaveKey('$schema')
+        ->toHaveKey('title', 'IgnoredTitle');
 
-    $out = (new BuildsArrayFixture())->assemble([
+    $out = new BuildsArrayFixture()->assemble([
         'schema' => $stringSchema,
     ]);
 
@@ -202,7 +202,7 @@ public function assemble(array $fields): array
     expect($objectSchema->getTitle())->toBe('consults')
         ->and($objectSchema->getInitialTitle())->toBe('Consult');
 
-    $out = (new BuildsArrayFixture())->assemble([
+    $out = new BuildsArrayFixture()->assemble([
         'schema' => $objectSchema,
     ]);
 
@@ -211,8 +211,8 @@ public function assemble(array $fields): array
             'type' => 'object',
             'title' => 'consults',
         ],
-    ]);
-    expect($out['schema'])->not->toHaveKey('$schema');
+    ])
+        ->and($out['schema'])->not->toHaveKey('$schema');
 });
 
 it('keeps a JsonSchema title set on a schema that had no constructor title', function (): void {
@@ -221,7 +221,7 @@ public function assemble(array $fields): array
     expect($stringSchema->getTitle())->toBe('IsoDateTime')
         ->and($stringSchema->getInitialTitle())->toBeNull();
 
-    $out = (new BuildsArrayFixture())->assemble([
+    $out = new BuildsArrayFixture()->assemble([
         'schema' => $stringSchema,
     ]);
 
@@ -236,7 +236,7 @@ public function assemble(array $fields): array
 it('strips a JsonSchema title that merely restates the constructor argument', function (): void {
     $stringSchema = Schema::string('IsoDateTime')->title('IsoDateTime');
 
-    $out = (new BuildsArrayFixture())->assemble([
+    $out = new BuildsArrayFixture()->assemble([
         'schema' => $stringSchema,
     ]);
 
diff --git a/tests/Unit/Concerns/HasExtensionsTest.php b/tests/Unit/Concerns/HasExtensionsTest.php
index 9c020ea..349c7ef 100644
--- a/tests/Unit/Concerns/HasExtensionsTest.php
+++ b/tests/Unit/Concerns/HasExtensionsTest.php
@@ -6,9 +6,6 @@
 
 covers(HasExtensions::class);
 
-/**
- * Fixture consumer used purely to exercise the HasExtensions trait.
- */
 final class HasExtensionsFixture
 {
     use HasExtensions;
@@ -65,5 +62,5 @@ final class HasExtensionsFixture
 });
 
 it('rejects an empty key', function (): void {
-    (new HasExtensionsFixture())->x('');
+    new HasExtensionsFixture()->x('');
 })->throws(InvalidArgumentException::class);
diff --git a/tests/Unit/IntegrationTest.php b/tests/Unit/IntegrationTest.php
index e307c7e..77d019a 100644
--- a/tests/Unit/IntegrationTest.php
+++ b/tests/Unit/IntegrationTest.php
@@ -131,14 +131,32 @@ function buildPetstore(): OpenApi
     $openApi->validate();
 
     $arr = $openApi->toArray();
-
-    expect($arr['openapi'])->toBe('3.1.0');
-    expect($arr['info']['title'])->toBe('Swagger Petstore');
-    expect($arr['x-api-id'])->toBe('petstore-1');
-    expect($arr['paths']['/pets']['get']['operationId'])->toBe('listPets');
-    expect($arr['paths']['/pets']['post']['callbacks']['onPetCreate'])->toHaveKey('{$request.body#/webhookUrl}');
-    expect($arr['webhooks']['pet.deleted']['post']['operationId'])->toBe('petDeletedWebhook');
-    expect($arr['components']['securitySchemes']['OAuth2']['type'])->toBe('oauth2');
+    $info = expectArray($arr['info']);
+    $paths = expectArray($arr['paths']);
+    $pets = expectArray($paths['/pets']);
+    $get = expectArray($pets['get']);
+    $post = expectArray($pets['post']);
+    $callbacks = expectArray($post['callbacks']);
+    $webhooks = expectArray($arr['webhooks']);
+    $petDeleted = expectArray($webhooks['pet.deleted']);
+    $petDeletedPost = expectArray($petDeleted['post']);
+    $components = expectArray($arr['components']);
+    $securitySchemes = expectArray($components['securitySchemes']);
+    $oauth2 = expectArray($securitySchemes['OAuth2']);
+
+    expect($arr['openapi'])->toBe('3.1.0')
+        ->and($info['title'])
+        ->toBe('Swagger Petstore')
+        ->and($arr['x-api-id'])
+        ->toBe('petstore-1')
+        ->and($get['operationId'])
+        ->toBe('listPets')
+        ->and($callbacks['onPetCreate'])
+        ->toHaveKey('{$request.body#/webhookUrl}')
+        ->and($petDeletedPost['operationId'])
+        ->toBe('petDeletedWebhook')
+        ->and($oauth2['type'])
+        ->toBe('oauth2');
 });
 
 it('round-trips through JSON encoding', function (): void {
@@ -171,16 +189,22 @@ function buildPetstore(): OpenApi
             ),
         );
 
-    $inline = $openApi->toArray()['paths']['/foo']['get']['responses']['200']['content']['application/json']['schema'];
-
-    expect($inline)->not->toHaveKey('$schema');
-    expect($inline)->not->toHaveKey('title');
-    expect($inline)->toBe([
-        'type' => 'object',
-        'properties' => [
-            'bar' => [
-                'type' => 'string',
+    $paths = expectArray($openApi->toArray()['paths']);
+    $foo = expectArray($paths['/foo']);
+    $get = expectArray($foo['get']);
+    $responses = expectArray($get['responses']);
+    $ok = expectArray($responses['200']);
+    $content = expectArray($ok['content']);
+    $json = expectArray($content['application/json']);
+    $inline = $json['schema'];
+
+    expect($inline)->not->toHaveKey('$schema')->not->toHaveKey('title')
+        ->toBe([
+            'type' => 'object',
+            'properties' => [
+                'bar' => [
+                    'type' => 'string',
+                ],
             ],
-        ],
-    ]);
+        ]);
 });
diff --git a/tests/Unit/Objects/ComponentsTest.php b/tests/Unit/Objects/ComponentsTest.php
index fa1b1e2..d62fcd8 100644
--- a/tests/Unit/Objects/ComponentsTest.php
+++ b/tests/Unit/Objects/ComponentsTest.php
@@ -21,7 +21,8 @@
 covers(Components::class);
 
 it('emits nothing by default', function (): void {
-    expect(Components::create()->toArray())->toBe([]);
+    expect(Components::create()->toArray())
+        ->toBeEmpty();
 });
 
 it('registers schemas', function (): void {
diff --git a/tests/Unit/Objects/ExampleTest.php b/tests/Unit/Objects/ExampleTest.php
index 8ce7296..952fb30 100644
--- a/tests/Unit/Objects/ExampleTest.php
+++ b/tests/Unit/Objects/ExampleTest.php
@@ -7,7 +7,8 @@
 covers(Example::class);
 
 it('emits an empty array when no fields are set', function (): void {
-    expect(Example::create()->toArray())->toBe([]);
+    expect(Example::create()->toArray())
+        ->toBeEmpty();
 });
 
 it('emits every field when set', function (): void {
@@ -52,5 +53,6 @@
 
     $example->clearValue();
 
-    expect($example->toArray())->toBe([]);
+    expect($example->toArray())
+        ->toBeEmpty();
 });
diff --git a/tests/Unit/Objects/ExternalDocsTest.php b/tests/Unit/Objects/ExternalDocsTest.php
index 9c37c38..eb7eca2 100644
--- a/tests/Unit/Objects/ExternalDocsTest.php
+++ b/tests/Unit/Objects/ExternalDocsTest.php
@@ -9,12 +9,11 @@
 it('emits url and optional description', function (): void {
     expect(ExternalDocs::create('https://example.com/docs')->toArray())->toBe([
         'url' => 'https://example.com/docs',
-    ]);
-
-    expect(
-        ExternalDocs::create('https://example.com/docs')->description('More info')->toArray(),
-    )->toBe([
-        'url' => 'https://example.com/docs',
-        'description' => 'More info',
-    ]);
+    ])
+        ->and(ExternalDocs::create('https://example.com/docs')->description('More info')
+            ->toArray())
+        ->toBe([
+            'url' => 'https://example.com/docs',
+            'description' => 'More info',
+        ]);
 });
diff --git a/tests/Unit/Objects/HeaderTest.php b/tests/Unit/Objects/HeaderTest.php
index 78f4a3d..4794770 100644
--- a/tests/Unit/Objects/HeaderTest.php
+++ b/tests/Unit/Objects/HeaderTest.php
@@ -9,7 +9,8 @@
 covers(Header::class);
 
 it('emits nothing by default', function (): void {
-    expect(Header::create()->toArray())->toBe([]);
+    expect(Header::create()->toArray())
+        ->toBeEmpty();
 });
 
 it('emits a schema-based header', function (): void {
diff --git a/tests/Unit/Objects/LinkTest.php b/tests/Unit/Objects/LinkTest.php
index 294ade0..3c94e2f 100644
--- a/tests/Unit/Objects/LinkTest.php
+++ b/tests/Unit/Objects/LinkTest.php
@@ -8,7 +8,8 @@
 covers(Link::class);
 
 it('emits nothing when empty', function (): void {
-    expect(Link::create()->toArray())->toBe([]);
+    expect(Link::create()->toArray())
+        ->toBeEmpty();
 });
 
 it('emits operationId-based link', function (): void {
@@ -65,13 +66,14 @@
 
     $array = $link->toArray();
 
-    expect($array)->toHaveKey('requestBody');
-    expect($array['requestBody'])->toBe([
-        'key' => 'value',
-    ]);
+    expect($array)->toHaveKey('requestBody')
+        ->and($array['requestBody'])
+        ->toBe([
+            'key' => 'value',
+        ]);
 
     $keys = array_keys($array);
-    expect(array_search('requestBody', $keys, true))->toBeGreaterThan(array_search('parameters', $keys, true));
+    expect(keyIndex($keys, 'requestBody'))->toBeGreaterThan(keyIndex($keys, 'parameters'));
 });
 
 it('inserts requestBody before description when no parameters present', function (): void {
@@ -84,7 +86,7 @@
 
     expect($array)->toHaveKey('requestBody');
     $keys = array_keys($array);
-    expect(array_search('requestBody', $keys, true))->toBeLessThan(array_search('description', $keys, true));
+    expect(keyIndex($keys, 'requestBody'))->toBeLessThan(keyIndex($keys, 'description'));
 });
 
 it('inserts requestBody before server when no parameters or description', function (): void {
@@ -99,7 +101,7 @@
 
     expect($array)->toHaveKey('requestBody');
     $keys = array_keys($array);
-    expect(array_search('requestBody', $keys, true))->toBeLessThan(array_search('server', $keys, true));
+    expect(keyIndex($keys, 'requestBody'))->toBeLessThan(keyIndex($keys, 'server'));
 });
 
 it('appends requestBody at end when no parameters, description, or server', function (): void {
@@ -111,6 +113,7 @@
 
     $array = $link->toArray();
 
-    expect($array)->toHaveKey('requestBody');
-    expect(array_key_last($array))->toBe('requestBody');
+    expect($array)->toHaveKey('requestBody')
+        ->and(array_key_last($array))
+        ->toBe('requestBody');
 });
diff --git a/tests/Unit/Objects/MediaTypeTest.php b/tests/Unit/Objects/MediaTypeTest.php
index bae6d4b..c0698a0 100644
--- a/tests/Unit/Objects/MediaTypeTest.php
+++ b/tests/Unit/Objects/MediaTypeTest.php
@@ -11,14 +11,28 @@
 covers(MediaType::class);
 
 it('knows its own content type', function (): void {
-    expect(MediaType::json()->getContentType())->toBe('application/json');
-    expect(MediaType::xml()->getContentType())->toBe('application/xml');
-    expect(MediaType::form()->getContentType())->toBe('application/x-www-form-urlencoded');
-    expect(MediaType::multipart()->getContentType())->toBe('multipart/form-data');
-    expect(MediaType::text()->getContentType())->toBe('text/plain');
-    expect(MediaType::html()->getContentType())->toBe('text/html');
-    expect(MediaType::octetStream()->getContentType())->toBe('application/octet-stream');
-    expect(MediaType::of('application/pdf')->getContentType())->toBe('application/pdf');
+    expect(MediaType::json()->getContentType())->toBe('application/json')
+        ->and(MediaType::xml()
+            ->getContentType())
+        ->toBe('application/xml')
+        ->and(MediaType::form()
+            ->getContentType())
+        ->toBe('application/x-www-form-urlencoded')
+        ->and(MediaType::multipart()
+            ->getContentType())
+        ->toBe('multipart/form-data')
+        ->and(MediaType::text()
+            ->getContentType())
+        ->toBe('text/plain')
+        ->and(MediaType::html()
+            ->getContentType())
+        ->toBe('text/html')
+        ->and(MediaType::octetStream()
+            ->getContentType())
+        ->toBe('application/octet-stream')
+        ->and(MediaType::of('application/pdf')
+            ->getContentType())
+        ->toBe('application/pdf');
 });
 
 it('accepts a JsonSchema and strips $schema/title when serialized', function (): void {
@@ -91,7 +105,7 @@
         ]);
 
     $keys = array_keys($mediaType->toArray());
-    expect(array_search('example', $keys, true))->toBeLessThan(array_search('encoding', $keys, true));
+    expect(keyIndex($keys, 'example'))->toBeLessThan(keyIndex($keys, 'encoding'));
 });
 
 it('example appears at end when only schema present', function (): void {
diff --git a/tests/Unit/Objects/OAuthFlowsTest.php b/tests/Unit/Objects/OAuthFlowsTest.php
index 4e9ae86..346c7d4 100644
--- a/tests/Unit/Objects/OAuthFlowsTest.php
+++ b/tests/Unit/Objects/OAuthFlowsTest.php
@@ -8,7 +8,8 @@
 covers(OAuthFlows::class, OAuthFlow::class);
 
 it('emits nothing by default', function (): void {
-    expect(OAuthFlows::create()->toArray())->toBe([]);
+    expect(OAuthFlows::create()->toArray())
+        ->toBeEmpty();
 });
 
 it('emits all four flows when configured', function (): void {
diff --git a/tests/Unit/Objects/OperationTest.php b/tests/Unit/Objects/OperationTest.php
index ba02f7a..eea1775 100644
--- a/tests/Unit/Objects/OperationTest.php
+++ b/tests/Unit/Objects/OperationTest.php
@@ -20,18 +20,33 @@
 covers(Operation::class);
 
 it('knows its HTTP method', function (): void {
-    expect(Operation::get()->getMethod())->toBe(HttpMethod::Get);
-    expect(Operation::post()->getMethod())->toBe(HttpMethod::Post);
-    expect(Operation::put()->getMethod())->toBe(HttpMethod::Put);
-    expect(Operation::patch()->getMethod())->toBe(HttpMethod::Patch);
-    expect(Operation::delete()->getMethod())->toBe(HttpMethod::Delete);
-    expect(Operation::options()->getMethod())->toBe(HttpMethod::Options);
-    expect(Operation::head()->getMethod())->toBe(HttpMethod::Head);
-    expect(Operation::trace()->getMethod())->toBe(HttpMethod::Trace);
+    expect(Operation::get()->getMethod())->toBe(HttpMethod::Get)
+        ->and(Operation::post()
+            ->getMethod())
+        ->toBe(HttpMethod::Post)
+        ->and(Operation::put()
+            ->getMethod())
+        ->toBe(HttpMethod::Put)
+        ->and(Operation::patch()
+            ->getMethod())
+        ->toBe(HttpMethod::Patch)
+        ->and(Operation::delete()
+            ->getMethod())
+        ->toBe(HttpMethod::Delete)
+        ->and(Operation::options()
+            ->getMethod())
+        ->toBe(HttpMethod::Options)
+        ->and(Operation::head()
+            ->getMethod())
+        ->toBe(HttpMethod::Head)
+        ->and(Operation::trace()
+            ->getMethod())
+        ->toBe(HttpMethod::Trace);
 });
 
 it('emits nothing by default', function (): void {
-    expect(Operation::get()->toArray())->toBe([]);
+    expect(Operation::get()->toArray())
+        ->toBeEmpty();
 });
 
 it('emits tags/summary/description/operationId/deprecated', function (): void {
@@ -182,6 +197,6 @@
         ->callback('onError', Callback::ref('OnError'));
 
     $arr = $operation->toArray();
-    expect($arr['callbacks'])->toHaveKey('onData');
-    expect($arr['callbacks'])->toHaveKey('onError');
+    expect($arr['callbacks'])->toHaveKey('onData')
+        ->toHaveKey('onError');
 });
diff --git a/tests/Unit/Objects/PathItemTest.php b/tests/Unit/Objects/PathItemTest.php
index 1359a52..9eec251 100644
--- a/tests/Unit/Objects/PathItemTest.php
+++ b/tests/Unit/Objects/PathItemTest.php
@@ -89,15 +89,17 @@
         );
 
     $result = $pathItem->toArray();
-    expect($result['servers'])->toBe([
+    $servers = expectArray($result['servers']);
+    expect($servers)->toBe([
         [
             'url' => 'https://api.example.com',
         ],
         [
             'url' => 'https://staging.example.com',
         ],
-    ]);
-    expect(array_is_list($result['servers']))->toBeTrue();
+    ])
+        ->and($servers)
+        ->toBeList();
 });
 
 it('parameters() preserves values as a list', function (): void {
@@ -108,6 +110,9 @@
         );
 
     $result = $pathItem->toArray();
-    expect(array_is_list($result['parameters']))->toBeTrue();
-    expect($result['parameters'])->toHaveCount(2);
+    $parameters = expectArray($result['parameters']);
+    expect($parameters)
+        ->toBeList()
+        ->and($parameters)
+        ->toHaveCount(2);
 });
diff --git a/tests/Unit/Objects/ReferenceTest.php b/tests/Unit/Objects/ReferenceTest.php
index 2013d83..cd5fd79 100644
--- a/tests/Unit/Objects/ReferenceTest.php
+++ b/tests/Unit/Objects/ReferenceTest.php
@@ -3,14 +3,12 @@
 declare(strict_types=1);
 
 use Cortex\OpenApi\Objects\Reference;
-use Cortex\OpenApi\Contracts\Serializable;
 
 covers(Reference::class);
 
 it('builds a basic $ref array', function (): void {
     $reference = Reference::to('#/components/schemas/User');
 
-    expect($reference)->toBeInstanceOf(Serializable::class);
     expect($reference->toArray())->toBe([
         '$ref' => '#/components/schemas/User',
     ]);
@@ -45,41 +43,50 @@
 it('provides typed shortcuts for every component bucket', function (): void {
     expect(Reference::schema('User')->toArray())->toBe([
         '$ref' => '#/components/schemas/User',
-    ]);
-
-    expect(Reference::response('NotFound')->toArray())->toBe([
-        '$ref' => '#/components/responses/NotFound',
-    ]);
-
-    expect(Reference::parameter('PetId')->toArray())->toBe([
-        '$ref' => '#/components/parameters/PetId',
-    ]);
-
-    expect(Reference::requestBody('CreateUser')->toArray())->toBe([
-        '$ref' => '#/components/requestBodies/CreateUser',
-    ]);
-
-    expect(Reference::header('RateLimit')->toArray())->toBe([
-        '$ref' => '#/components/headers/RateLimit',
-    ]);
-
-    expect(Reference::example('Sample')->toArray())->toBe([
-        '$ref' => '#/components/examples/Sample',
-    ]);
-
-    expect(Reference::link('NextPage')->toArray())->toBe([
-        '$ref' => '#/components/links/NextPage',
-    ]);
-
-    expect(Reference::callback('OnCreate')->toArray())->toBe([
-        '$ref' => '#/components/callbacks/OnCreate',
-    ]);
-
-    expect(Reference::securityScheme('BearerAuth')->toArray())->toBe([
-        '$ref' => '#/components/securitySchemes/BearerAuth',
-    ]);
-
-    expect(Reference::pathItem('UserById')->toArray())->toBe([
-        '$ref' => '#/components/pathItems/UserById',
-    ]);
+    ])
+        ->and(Reference::response('NotFound')
+            ->toArray())
+        ->toBe([
+            '$ref' => '#/components/responses/NotFound',
+        ])
+        ->and(Reference::parameter('PetId')
+            ->toArray())
+        ->toBe([
+            '$ref' => '#/components/parameters/PetId',
+        ])
+        ->and(Reference::requestBody('CreateUser')
+            ->toArray())
+        ->toBe([
+            '$ref' => '#/components/requestBodies/CreateUser',
+        ])
+        ->and(Reference::header('RateLimit')
+            ->toArray())
+        ->toBe([
+            '$ref' => '#/components/headers/RateLimit',
+        ])
+        ->and(Reference::example('Sample')
+            ->toArray())
+        ->toBe([
+            '$ref' => '#/components/examples/Sample',
+        ])
+        ->and(Reference::link('NextPage')
+            ->toArray())
+        ->toBe([
+            '$ref' => '#/components/links/NextPage',
+        ])
+        ->and(Reference::callback('OnCreate')
+            ->toArray())
+        ->toBe([
+            '$ref' => '#/components/callbacks/OnCreate',
+        ])
+        ->and(Reference::securityScheme('BearerAuth')
+            ->toArray())
+        ->toBe([
+            '$ref' => '#/components/securitySchemes/BearerAuth',
+        ])
+        ->and(Reference::pathItem('UserById')
+            ->toArray())
+        ->toBe([
+            '$ref' => '#/components/pathItems/UserById',
+        ]);
 });
diff --git a/tests/Unit/Objects/RequestBodyTest.php b/tests/Unit/Objects/RequestBodyTest.php
index c1f6456..3474e1b 100644
--- a/tests/Unit/Objects/RequestBodyTest.php
+++ b/tests/Unit/Objects/RequestBodyTest.php
@@ -90,7 +90,8 @@
 it('json() accepts a Reference', function (): void {
     $requestBody = RequestBody::create()->json(Reference::schema('CreateUser'));
 
-    expect($requestBody->toArray()['content']['application/json'])->toBe([
+    $content = expectArray($requestBody->toArray()['content']);
+    expect($content['application/json'])->toBe([
         'schema' => [
             '$ref' => '#/components/schemas/CreateUser',
         ],
diff --git a/tests/Unit/Objects/ResponseTest.php b/tests/Unit/Objects/ResponseTest.php
index cd716bc..11ff408 100644
--- a/tests/Unit/Objects/ResponseTest.php
+++ b/tests/Unit/Objects/ResponseTest.php
@@ -12,37 +12,42 @@
 covers(Response::class);
 
 it('named 200 response uses "OK" description by default', function (): void {
-    expect(Response::ok()->getStatusCode())->toBe('200');
-    expect(Response::ok()->toArray())->toBe([
-        'description' => 'OK',
-    ]);
+    expect(Response::ok()->getStatusCode())->toBe('200')
+        ->and(Response::ok()
+            ->toArray())
+        ->toBe([
+            'description' => 'OK',
+        ]);
 });
 
 it('named 404 response', function (): void {
     $response = Response::notFound();
 
-    expect($response->getStatusCode())->toBe('404');
-    expect($response->toArray())->toBe([
-        'description' => 'Not Found',
-    ]);
+    expect($response->getStatusCode())->toBe('404')
+        ->and($response->toArray())
+        ->toBe([
+            'description' => 'Not Found',
+        ]);
 });
 
 it('arbitrary status via status()', function (): void {
     $response = Response::status(418)->description("I'm a teapot");
 
-    expect($response->getStatusCode())->toBe('418');
-    expect($response->toArray())->toBe([
-        'description' => "I'm a teapot",
-    ]);
+    expect($response->getStatusCode())->toBe('418')
+        ->and($response->toArray())
+        ->toBe([
+            'description' => "I'm a teapot",
+        ]);
 });
 
 it('default response uses the default key', function (): void {
     $response = Response::default()->description('Unexpected error');
 
-    expect($response->getStatusCode())->toBe('default');
-    expect($response->toArray())->toBe([
-        'description' => 'Unexpected error',
-    ]);
+    expect($response->getStatusCode())->toBe('default')
+        ->and($response->toArray())
+        ->toBe([
+            'description' => 'Unexpected error',
+        ]);
 });
 
 it('emits content, headers, and links', function (): void {
@@ -125,7 +130,8 @@
 it('json() accepts a Reference', function (): void {
     $response = Response::notFound()->json(Reference::schema('Error'));
 
-    expect($response->toArray()['content']['application/json'])->toBe([
+    $content = expectArray($response->toArray()['content']);
+    expect($content['application/json'])->toBe([
         'schema' => [
             '$ref' => '#/components/schemas/Error',
         ],
@@ -133,6 +139,7 @@
 });
 
 it('json() with no schema emits an empty application/json key', function (): void {
-    expect(Response::ok()->json()->toArray())->toHaveKey('content');
-    expect(Response::ok()->json()->toArray()['content'])->toHaveKey('application/json');
+    expect(Response::ok()->json()->toArray())->toHaveKey('content')
+        ->and(Response::ok()->json()->toArray()['content'])
+        ->toHaveKey('application/json');
 });
diff --git a/tests/Unit/Objects/SecurityRequirementTest.php b/tests/Unit/Objects/SecurityRequirementTest.php
index 06d72be..6051999 100644
--- a/tests/Unit/Objects/SecurityRequirementTest.php
+++ b/tests/Unit/Objects/SecurityRequirementTest.php
@@ -19,5 +19,6 @@
 });
 
 it('builds an empty requirement (public access)', function (): void {
-    expect(SecurityRequirement::public()->toArray())->toBe([]);
+    expect(SecurityRequirement::public()->toArray())
+        ->toBeEmpty();
 });
diff --git a/tests/Unit/Objects/XmlTest.php b/tests/Unit/Objects/XmlTest.php
index e38f697..7127b37 100644
--- a/tests/Unit/Objects/XmlTest.php
+++ b/tests/Unit/Objects/XmlTest.php
@@ -7,7 +7,8 @@
 covers(Xml::class);
 
 it('emits nothing by default', function (): void {
-    expect(Xml::create()->toArray())->toBe([]);
+    expect(Xml::create()->toArray())
+        ->toBeEmpty();
 });
 
 it('emits every field', function (): void {
diff --git a/tests/Unit/OpenApiTest.php b/tests/Unit/OpenApiTest.php
index 87d2092..ccbe999 100644
--- a/tests/Unit/OpenApiTest.php
+++ b/tests/Unit/OpenApiTest.php
@@ -120,8 +120,10 @@
 });
 
 it('knows its OpenAPI version enum', function (): void {
-    expect(OpenApi::create(OpenApiVersion::V3_1_0)->getVersion())->toBe(OpenApiVersion::V3_1_0);
-    expect(OpenApi::create(OpenApiVersion::V3_1_1)->getVersion())->toBe(OpenApiVersion::V3_1_1);
+    expect(OpenApi::create(OpenApiVersion::V3_1_0)->getVersion())->toBe(OpenApiVersion::V3_1_0)
+        ->and(OpenApi::create(OpenApiVersion::V3_1_1)
+            ->getVersion())
+        ->toBe(OpenApiVersion::V3_1_1);
 });
 
 it('supports vendor extensions at the root', function (): void {
@@ -129,7 +131,8 @@
         ->info(Info::create('x', '1'))
         ->x('x-internal', true);
 
-    expect($openApi->toArray()['x-internal'])->toBe(true);
+    expect($openApi->toArray()['x-internal'])
+        ->toBeTrue();
 });
 
 it('path() adds a PathItem or Reference by explicit pattern', function (): void {
@@ -140,12 +143,12 @@
         ))
         ->path('/legacy', Reference::pathItem('LegacyUsers'));
 
-    $arr = $openApi->toArray();
-    expect($arr['paths'])->toHaveKey('/users');
-    expect($arr['paths'])->toHaveKey('/legacy');
-    expect($arr['paths']['/legacy'])->toBe([
-        '$ref' => '#/components/pathItems/LegacyUsers',
-    ]);
+    $paths = expectArray($openApi->toArray()['paths']);
+    expect($paths)->toHaveKeys(['/users', '/legacy'])
+        ->and($paths['/legacy'])
+        ->toBe([
+            '$ref' => '#/components/pathItems/LegacyUsers',
+        ]);
 });
 
 it('adds webhooks one at a time with webhook()', function (): void {
diff --git a/tests/Unit/Validation/ComponentsTest.php b/tests/Unit/Validation/ComponentsTest.php
index 9ec5736..5123773 100644
--- a/tests/Unit/Validation/ComponentsTest.php
+++ b/tests/Unit/Validation/ComponentsTest.php
@@ -16,7 +16,8 @@
             Components::create()->schema('Invalid Key!', Schema::object()),
         );
 
-    expect($openApi)->toFailOpenApiValidationAt(
+    assertOpenApiValidationFailsAt(
+        $openApi,
         '/components/schemas',
         'The string should match pattern: ^[a-zA-Z0-9._-]+$',
     );
diff --git a/tests/Unit/Validation/DocumentTest.php b/tests/Unit/Validation/DocumentTest.php
index bd92979..426a005 100644
--- a/tests/Unit/Validation/DocumentTest.php
+++ b/tests/Unit/Validation/DocumentTest.php
@@ -24,7 +24,7 @@
             ),
         );
 
-    expect($openApi)->toPassOpenApiValidation();
+    assertOpenApiValidationPasses($openApi);
 });
 
 it('accepts a minimal valid 3.1.1 document', function (): void {
@@ -36,7 +36,7 @@
             ),
         );
 
-    expect($openApi)->toPassOpenApiValidation();
+    assertOpenApiValidationPasses($openApi);
 });
 
 it('accepts a document with components, tags, and schemas', function (): void {
@@ -52,13 +52,14 @@
             ),
         );
 
-    expect($openApi)->toPassOpenApiValidation();
+    assertOpenApiValidationPasses($openApi);
 });
 
 it('rejects a document missing info', function (): void {
     $openApi = OpenApi::create();
 
-    expect($openApi)->toFailOpenApiValidationAt(
+    assertOpenApiValidationFailsAt(
+        $openApi,
         '/',
         'The required properties (info) are missing',
     );
@@ -69,7 +70,7 @@
         ->info(Info::create('x', '1.0.0'))
         ->components(Components::create()->schema('User', Schema::object()));
 
-    expect($openApi)->toPassOpenApiValidation();
+    assertOpenApiValidationPasses($openApi);
 });
 
 it('accepts a webhooks-only document without paths or components', function (): void {
@@ -81,14 +82,14 @@
             ),
         ]);
 
-    expect($openApi)->toPassOpenApiValidation();
+    assertOpenApiValidationPasses($openApi);
 });
 
 it('rejects a document with info but no paths, components, or webhooks', function (): void {
     $openApi = OpenApi::create()
         ->info(Info::create('x', '1.0.0'));
 
-    expect($openApi)->toFailOpenApiValidation([
+    assertOpenApiValidationErrors($openApi, [
         '/' => [
             'The required properties (paths) are missing',
             'The required properties (components) are missing',
diff --git a/tests/Unit/Validation/ExampleTest.php b/tests/Unit/Validation/ExampleTest.php
index 98b4294..db623f3 100644
--- a/tests/Unit/Validation/ExampleTest.php
+++ b/tests/Unit/Validation/ExampleTest.php
@@ -21,7 +21,8 @@
                     ->externalValue('https://example.com/examples/user.json')),
         );
 
-    expect($openApi)->toFailOpenApiValidationAt(
+    assertOpenApiValidationFailsAt(
+        $openApi,
         '/components/examples/Bad',
         'The data must not match schema',
     );
diff --git a/tests/Unit/Validation/LicenseTest.php b/tests/Unit/Validation/LicenseTest.php
index 9ea419f..09c9025 100644
--- a/tests/Unit/Validation/LicenseTest.php
+++ b/tests/Unit/Validation/LicenseTest.php
@@ -20,7 +20,8 @@
         )
         ->components(Components::create()->schema('Empty', Schema::object()));
 
-    expect($openApi)->toFailOpenApiValidationAt(
+    assertOpenApiValidationFailsAt(
+        $openApi,
         '/info/license',
         'The data must not match schema',
     );
diff --git a/tests/Unit/Validation/ParameterTest.php b/tests/Unit/Validation/ParameterTest.php
index 3e02bb6..8372fec 100644
--- a/tests/Unit/Validation/ParameterTest.php
+++ b/tests/Unit/Validation/ParameterTest.php
@@ -28,7 +28,7 @@
             ),
         );
 
-    expect($openApi)->toPassOpenApiValidation();
+    assertOpenApiValidationPasses($openApi);
 });
 
 it('rejects a parameter with neither schema nor content', function (): void {
@@ -42,7 +42,7 @@
             ),
         );
 
-    expect($openApi)->toFailOpenApiValidation([
+    assertOpenApiValidationErrors($openApi, [
         '/paths/~1ping/get/parameters/0' => [
             'The required properties (schema) are missing',
             'The required properties (content) are missing',
@@ -61,7 +61,8 @@
             ),
         );
 
-    expect($openApi)->toFailOpenApiValidationAt(
+    assertOpenApiValidationFailsAt(
+        $openApi,
         '/paths/~1items~1%7Bid%7D/get/parameters/0/required',
         'The data must match the const value',
     );
diff --git a/tests/Unit/Validation/PathsTest.php b/tests/Unit/Validation/PathsTest.php
index 4e97f76..54f652d 100644
--- a/tests/Unit/Validation/PathsTest.php
+++ b/tests/Unit/Validation/PathsTest.php
@@ -17,7 +17,8 @@
             Operation::get()->responses(Response::ok()),
         ));
 
-    expect($openApi)->toFailOpenApiValidationAt(
+    assertOpenApiValidationFailsAt(
+        $openApi,
         '/paths',
         'Unevaluated object properties not allowed: noslash',
     );
diff --git a/tests/Unit/Validation/RequestBodyTest.php b/tests/Unit/Validation/RequestBodyTest.php
index 2f378ee..12caadd 100644
--- a/tests/Unit/Validation/RequestBodyTest.php
+++ b/tests/Unit/Validation/RequestBodyTest.php
@@ -24,7 +24,7 @@
             ),
         );
 
-    expect($openApi)->toPassOpenApiValidation();
+    assertOpenApiValidationPasses($openApi);
 });
 
 it('rejects a requestBody with no content', function (): void {
@@ -36,7 +36,8 @@
             Components::create()->requestBody('Body', RequestBody::create()),
         );
 
-    expect($openApi)->toFailOpenApiValidationAt(
+    assertOpenApiValidationFailsAt(
+        $openApi,
         '/components/requestBodies/Body',
         'The data (array) must match the type: object',
     );
diff --git a/tests/Unit/Validation/ResponseTest.php b/tests/Unit/Validation/ResponseTest.php
index f139f3b..9ce7992 100644
--- a/tests/Unit/Validation/ResponseTest.php
+++ b/tests/Unit/Validation/ResponseTest.php
@@ -23,7 +23,8 @@
             ),
         );
 
-    expect($openApi)->toFailOpenApiValidationAt(
+    assertOpenApiValidationFailsAt(
+        $openApi,
         '/paths/~1ping/get/responses',
         'Unevaluated object properties not allowed: 99',
     );
@@ -42,7 +43,7 @@
             ),
         );
 
-    expect($openApi)->toPassOpenApiValidation();
+    assertOpenApiValidationPasses($openApi);
 });
 
 it('rejects a response object missing its description', function (): void {
@@ -55,7 +56,8 @@
             ),
         );
 
-    expect($openApi)->toFailOpenApiValidationAt(
+    assertOpenApiValidationFailsAt(
+        $openApi,
         '/paths/~1ping/get/responses/503',
         'The data (array) must match the type: object',
     );
@@ -74,7 +76,7 @@
             ),
         );
 
-    expect($openApi)->toPassOpenApiValidation();
+    assertOpenApiValidationPasses($openApi);
 });
 
 it('rejects a link with neither operationRef nor operationId', function (): void {
@@ -88,7 +90,8 @@
             ),
         );
 
-    expect($openApi)->toFailOpenApiValidationAt(
+    assertOpenApiValidationFailsAt(
+        $openApi,
         '/paths/~1ping/get/responses/200/links/Empty',
         'The data (array) must match the type: object',
     );
diff --git a/tests/Unit/Validation/SecuritySchemeTest.php b/tests/Unit/Validation/SecuritySchemeTest.php
index 3a89298..a2aa499 100644
--- a/tests/Unit/Validation/SecuritySchemeTest.php
+++ b/tests/Unit/Validation/SecuritySchemeTest.php
@@ -36,7 +36,7 @@
                 ),
         );
 
-    expect($openApi)->toPassOpenApiValidation();
+    assertOpenApiValidationPasses($openApi);
 });
 
 it('rejects an oauth2 security scheme without flows', function (): void {
@@ -47,7 +47,8 @@
                 ->securityScheme('oauth2', SecurityScheme::oauth2()),
         );
 
-    expect($openApi)->toFailOpenApiValidationAt(
+    assertOpenApiValidationFailsAt(
+        $openApi,
         '/components/securitySchemes/oauth2',
         'The required properties (flows) are missing',
     );
diff --git a/tests/Unit/Validation/ValidationExceptionTest.php b/tests/Unit/Validation/ValidationExceptionTest.php
index 2c1beed..fbb9d27 100644
--- a/tests/Unit/Validation/ValidationExceptionTest.php
+++ b/tests/Unit/Validation/ValidationExceptionTest.php
@@ -3,6 +3,7 @@
 declare(strict_types=1);
 
 use Cortex\OpenApi\OpenApi;
+use PHPUnit\Framework\Assert;
 use Cortex\OpenApi\Exceptions\ValidationException;
 
 covers(OpenApi::class);
@@ -12,7 +13,7 @@
 
     try {
         $openApi->validate();
-        $this->fail('Expected ValidationException');
+        Assert::fail('Expected ValidationException');
     } catch (ValidationException $validationException) {
         expect($validationException->getMessage())->toContain('OpenAPI document failed meta-schema validation:');
     }
@@ -39,18 +40,18 @@
 
     try {
         $openApi->validate();
-        expect(true)->toBeFalse('Expected ValidationException');
+        Assert::fail('Expected ValidationException');
     } catch (ValidationException $validationException) {
         $errors = $validationException->errors();
-        expect($errors)->toBeArray();
-        expect($errors)->not->toBeEmpty();
-        expect($errors)->toHaveKey('/');
-        expect($errors['/'])->toBeArray();
-        expect($errors['/'][0])->toBe('The required properties (info) are missing');
+        expect($errors)->not->toBeEmpty()
+            ->toHaveKey('/');
+        $rootErrors = expectArray($errors['/']);
+        expect($rootErrors[0])->toBe('The required properties (info) are missing');
     }
 });
 
 it('ValidationException constructed without errors returns empty array from errors()', function (): void {
     $e = new ValidationException('Something went wrong');
-    expect($e->errors())->toBe([]);
+    expect($e->errors())
+        ->toBeEmpty();
 });
diff --git a/tests/phpstan/pest-expectations.stub b/tests/phpstan/pest-expectations.stub
deleted file mode 100644
index cf8d9aa..0000000
--- a/tests/phpstan/pest-expectations.stub
+++ /dev/null
@@ -1,18 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Pest;
-
-/**
- * Augments Pest's Expectation with project-specific expectations registered in tests/Expectations.php.
- *
- * @template TValue
- *
- * @method self<TValue> toFailOpenApiValidation(array<string, list<string>> $expectedErrors)
- * @method self<TValue> toFailOpenApiValidationAt(string $pointer, string $message)
- * @method self<TValue> toPassOpenApiValidation()
- */
-class Expectation
-{
-}