feat: add toHaveStudlyCaseKeys

tests/Features/Expect/toHaveStudlyCaseKeys.php

@@ -0,0 +1,31 @@
+<?php
+
+use Pest\Exceptions\InvalidExpectationValue;
+use PHPUnit\Framework\ExpectationFailedException;
+
+$array = [
+    'Studly' => true,
+    'StudlyCase' => [
+        'Studly' => true,
+        'StudlyCase' => [
+            'Studly' => true,
+            'StudlyCase' => true,
+        ],
+    ],
+];
+
+test('pass', function () use ($array) {
+    expect($array)->toHaveStudlyCaseKeys();
+});
+
+test('failures', function () {
+    expect('not-an-array')->toHaveStudlyCaseKeys();
+})->throws(InvalidExpectationValue::class);
+
+test('failures with message', function () use ($array) {
+    expect($array)->not->toHaveStudlyCaseKeys('oh no!');
+})->throws(ExpectationFailedException::class, 'oh no!');
+
+test('not failures', function () use ($array) {
+    expect($array)->not->toHaveStudlyCaseKeys();
+})->throws(ExpectationFailedException::class);