Add toBeFalsy

src/Expectation.php

@@ -225,6 +225,16 @@ final class Expectation
         return $this;
     }
 
+    /**
+     * Asserts that the value is falsy.
+     */
+    public function toBeFalsy(): Expectation
+    {
+        Assert::assertFalse((bool) $this->value);
+
+        return $this;
+    }
+
     /**
      * Asserts that the value is greater than $expected.
      *

tests/Features/Expect/ToBeFalsy.php

@@ -0,0 +1,26 @@
+<?php
+
+use PHPUnit\Framework\ExpectationFailedException;
+
+test('passes', function () {
+    expect(false)->toBeFalsy();
+    expect('')->toBeFalsy();
+    expect(null)->toBeFalsy();
+    expect([])->toBeFalsy();
+    expect(0)->toBeFalsy();
+    expect('0')->toBeFalsy();
+
+    expect(true)->not->toBeFalsy();
+    expect([1])->not->toBeFalsy();
+    expect('false')->not->toBeFalsy();
+    expect(1)->not->toBeFalsy();
+    expect(-1)->not->toBeFalsy();
+});
+
+test('failures', function () {
+    expect(1)->toBeFalsy();
+})->throws(ExpectationFailedException::class);
+
+test('not failures', function () {
+    expect(null)->not->toBeFalsy();
+})->throws(ExpectationFailedException::class);