feat: move Expectations API out of external plugin

tests/Features/Expect/HigherOrder/methods.php

@@ -0,0 +1,100 @@
+<?php
+
+it('can access methods', function () {
+    expect(new HasMethods())
+        ->name()->toBeString()->toEqual('Has Methods');
+});
+
+it('can access multiple methods', function () {
+    expect(new HasMethods())
+        ->name()->toBeString()->toEqual('Has Methods')
+        ->quantity()->toBeInt()->toEqual(20);
+});
+
+it('works with not', function () {
+    expect(new HasMethods())
+        ->name()->not->toEqual('world')->toEqual('Has Methods')
+        ->quantity()->toEqual(20)->not()->toEqual('bar')->not->toBeNull;
+});
+
+it('can accept arguments', function () {
+    expect(new HasMethods())
+        ->multiply(5, 4)->toBeInt->toEqual(20);
+});
+
+it('works with each', function () {
+    expect(new HasMethods())
+        ->attributes()->toBeArray->each->not()->toBeNull
+        ->attributes()->each(function ($attribute) {
+            $attribute->not->toBeNull();
+        });
+});
+
+it('works inside of each', function () {
+    expect(new HasMethods())
+        ->books()->each(function ($book) {
+            $book->title->not->toBeNull->cost->toBeGreaterThan(19);
+        });
+});
+
+it('works with sequence', function () {
+    expect(new HasMethods())
+        ->books()->sequence(
+            function ($book) { $book->title->toEqual('Foo')->cost->toEqual(20); },
+            function ($book) { $book->title->toEqual('Bar')->cost->toEqual(30); },
+        );
+});
+
+it('can compose complex expectations', function () {
+    expect(new HasMethods())
+        ->toBeObject()
+        ->name()->toEqual('Has Methods')->not()->toEqual('bar')
+        ->quantity()->not->toEqual('world')->toEqual(20)->toBeInt
+        ->multiply(3, 4)->not->toBeString->toEqual(12)
+        ->attributes()->toBeArray()
+        ->books()->toBeArray->each->not->toBeEmpty
+        ->books()->sequence(
+            function ($book) { $book->title->toEqual('Foo')->cost->toEqual(20); },
+            function ($book) { $book->title->toEqual('Bar')->cost->toEqual(30); },
+        );
+});
+
+class HasMethods
+{
+    public function name()
+    {
+        return 'Has Methods';
+    }
+
+    public function quantity()
+    {
+        return 20;
+    }
+
+    public function multiply($x, $y)
+    {
+        return $x * $y;
+    }
+
+    public function attributes()
+    {
+        return [
+            'name'     => $this->name(),
+            'quantity' => $this->quantity(),
+        ];
+    }
+
+    public function books()
+    {
+        return [
+            [
+                'title' => 'Foo',
+                'cost'  => 20,
+            ],
+            [
+                'title' => 'Bar',
+                'cost'  => 30,
+            ],
+        ];
+    }
+}