feat: add toHaveSnakeCaseKeys

src/Expectation.php

@@ -740,4 +740,26 @@ final class Expectation
             FileLineFinder::where(fn (string $line): bool => str_contains($line, 'class'))
         );
     }
+
+    /**
+     * Asserts that the given expectation is iterable and contains snake_case keys.
+     *
+     * @return self<TValue>
+     */
+    public function toHaveSnakeCaseKeys(string $message = ''): self
+    {
+        if (! is_iterable($this->value)) {
+            InvalidExpectationValue::expected('iterable');
+        }
+
+        foreach ($this->value as $k => $item) {
+            $this->and($k)->toBeSnakeCase($message);
+
+            if (is_array($item)) {
+                $this->and($item)->toHaveSnakeCaseKeys($message);
+            }
+        }
+
+        return $this;
+    }
 }

tests/Features/Expect/toHaveSnakeCaseKeys.php

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