feat(expect): adds toBe

src/OppositeExpectation.php

@@ -0,0 +1,45 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pest;
+
+use PHPUnit\Framework\ExpectationFailedException;
+
+/**
+ * @internal
+ *
+ * @mixin Expectation
+ */
+final class OppositeExpectation
+{
+    /**
+     * @var Expectation
+     */
+    private $original;
+
+    /**
+     * Creates a new opposite expectation.
+     */
+    public function __construct(Expectation $original)
+    {
+        $this->original = $original;
+    }
+
+    /**
+     * Handle dynamic method calls into the original expectation.
+     *
+     * @param array<int, mixed> $arguments
+     */
+    public function __call(string $name, array $arguments): Expectation
+    {
+        try {
+            /* @phpstan-ignore-next-line */
+            $this->original->{$name}(...$arguments);
+        } catch (ExpectationFailedException $e) {
+            return $this->original;
+        }
+
+        throw new ExpectationFailedException(sprintf('@todo'));
+    }
+}