Added toBeList expectation

src/Mixins/Expectation.php

@@ -467,6 +467,18 @@ final class Expectation
         return $this;
     }
 
+    /**
+     * Asserts that the value is a list.
+     *
+     * @return self<TValue>
+     */
+    public function toBeList(string $message = ''): self
+    {
+        Assert::assertIsList($this->value, $message);
+
+        return $this;
+    }
+
     /**
      * Asserts that the value is of type bool.
      *

tests/Features/Expect/toBeList.php

@@ -0,0 +1,20 @@
+<?php
+
+use PHPUnit\Framework\ExpectationFailedException;
+
+test('pass', function () {
+    expect([1, 2, 3])->toBeList();
+    expect(['a' => 1, 'b' => 2, 'c' => 3])->not->toBeList();
+});
+
+test('failures', function () {
+    expect(null)->toBeList();
+})->throws(ExpectationFailedException::class);
+
+test('failures with custom message', function () {
+    expect(null)->toBeList('oh no!');
+})->throws(ExpectationFailedException::class, 'oh no!');
+
+test('not failures', function () {
+    expect(['a', 'b', 'c'])->not->toBeList();
+})->throws(ExpectationFailedException::class);