From 03dc11c2f60bbc34a66c6376c1157beb9ba125c2 Mon Sep 17 00:00:00 2001
From: Nuno Maduro <enunomaduro@gmail.com>
Date: Sun, 29 Nov 2020 16:30:57 +0100
Subject: [PATCH] Adds expect extend

---
 src/Concerns/Extendable.php  | 55 ++++++++++++++++++++++++++++++++++++
 src/Expectation.php          |  3 ++
 src/Support/Extendable.php   | 33 ++++++++++++++++++++++
 src/globals.php              |  9 ++++--
 tests/.snapshots/success.txt |  8 +++++-
 tests/Expect/extend.php      | 29 +++++++++++++++++++
 6 files changed, 134 insertions(+), 3 deletions(-)
 create mode 100644 src/Concerns/Extendable.php
 create mode 100644 src/Support/Extendable.php
 create mode 100644 tests/Expect/extend.php

diff --git a/src/Concerns/Extendable.php b/src/Concerns/Extendable.php
new file mode 100644
index 00000000..41757a9f
--- /dev/null
+++ b/src/Concerns/Extendable.php
@@ -0,0 +1,55 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pest\Concerns;
+
+use BadMethodCallException;
+use Closure;
+
+/**
+ * @internal
+ */
+trait Extendable
+{
+    /**
+     * @var array<string, Closure>
+     */
+    private static $extends = [];
+
+    /**
+     * Register a custom extend.
+     */
+    public static function extend(string $name, Closure $extend): void
+    {
+        static::$extends[$name] = $extend;
+    }
+
+    /**
+     * Checks if extend is registered.
+     */
+    public static function hasExtend(string $name): bool
+    {
+        return array_key_exists($name, static::$extends);
+    }
+
+    /**
+     * Dynamically handle calls to the class.
+     *
+     * @param array<int, mixed> $parameters
+     *
+     * @return mixed
+     *
+     * @throws BadMethodCallException
+     */
+    public function __call(string $method, array $parameters)
+    {
+        if (!static::hasExtend($method)) {
+            throw new BadMethodCallException(sprintf('Method %s::%s does not exist.', static::class, $method));
+        }
+
+        $extend = static::$extends[$method]->bindTo($this, static::class);
+
+        return $extend(...$parameters);
+    }
+}
diff --git a/src/Expectation.php b/src/Expectation.php
index 0946c00f..2815ef14 100644
--- a/src/Expectation.php
+++ b/src/Expectation.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace Pest;
 
+use Pest\Concerns\Extendable;
 use PHPUnit\Framework\Assert;
 use PHPUnit\Framework\Constraint\Constraint;
 use SebastianBergmann\Exporter\Exporter;
@@ -15,6 +16,8 @@ use SebastianBergmann\Exporter\Exporter;
  */
 final class Expectation
 {
+    use Extendable;
+
     /**
      * The expectation value.
      *
diff --git a/src/Support/Extendable.php b/src/Support/Extendable.php
new file mode 100644
index 00000000..dcbb7a5a
--- /dev/null
+++ b/src/Support/Extendable.php
@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pest\Support;
+
+use Closure;
+
+final class Extendable
+{
+    /**
+     * The extendable class.
+     *
+     * @var string
+     */
+    private $extendableClass;
+
+    /**
+     * Creates a new extendable instance.
+     */
+    public function __construct(string $extendableClass)
+    {
+        $this->extendableClass = $extendableClass;
+    }
+
+    /**
+     * Register a custom extend.
+     */
+    public function extend(string $name, Closure $extend): void
+    {
+        $this->extendableClass::extend($name, $extend);
+    }
+}
diff --git a/src/globals.php b/src/globals.php
index 87bc6c4e..ed642a21 100644
--- a/src/globals.php
+++ b/src/globals.php
@@ -9,6 +9,7 @@ use Pest\PendingObjects\BeforeEachCall;
 use Pest\PendingObjects\TestCall;
 use Pest\PendingObjects\UsesCall;
 use Pest\Support\Backtrace;
+use Pest\Support\Extendable;
 use Pest\Support\HigherOrderTapProxy;
 use Pest\TestSuite;
 use PHPUnit\Framework\TestCase;
@@ -111,9 +112,13 @@ function afterAll(Closure $closure = null): void
  *
  * @param mixed $value the Value
  *
- * @return Expectation
+ * @return Expectation|Extendable
  */
-function expect($value)
+function expect($value = null)
 {
+    if (func_num_args() === 0) {
+        return new Extendable(Expectation::class);
+    }
+
     return test()->expect($value);
 }
diff --git a/tests/.snapshots/success.txt b/tests/.snapshots/success.txt
index 300d25c6..b8319ef8 100644
--- a/tests/.snapshots/success.txt
+++ b/tests/.snapshots/success.txt
@@ -2,6 +2,12 @@
    PASS  Tests\CustomTestCase\ExecutedTest
   ✓ that gets executed
 
+   PASS  Tests\Expect\extend
+  ✓ it macros true is true
+  ✓ it macros false is not true
+  ✓ it macros true is true with argument
+  ✓ it macros false is not true with argument
+
    PASS  Tests\Expect\not
   ✓ not property calls
 
@@ -404,5 +410,5 @@
   ✓ depends run test only once
   ✓ depends works with the correct test name
 
-  Tests:  7 skipped, 238 passed
+  Tests:  7 skipped, 242 passed
   
\ No newline at end of file
diff --git a/tests/Expect/extend.php b/tests/Expect/extend.php
new file mode 100644
index 00000000..4be88241
--- /dev/null
+++ b/tests/Expect/extend.php
@@ -0,0 +1,29 @@
+<?php
+
+expect()->extend('toBeAMacroExpectation', function () {
+    $this->toBeTrue();
+
+    return $this;
+});
+
+expect()->extend('toBeAMacroExpectationWithArguments', function (bool $value) {
+    $this->toBe($value);
+
+    return $this;
+});
+
+it('macros true is true', function () {
+    expect(true)->toBeAMacroExpectation();
+});
+
+it('macros false is not true', function () {
+    expect(false)->not->toBeAMacroExpectation();
+});
+
+it('macros true is true with argument', function () {
+    expect(true)->toBeAMacroExpectationWithArguments(true);
+});
+
+it('macros false is not true with argument', function () {
+    expect(false)->not->toBeAMacroExpectationWithArguments(true);
+});