update documentation including testing (#364)

* update documentation including testing

* readme improvement

readme.md

@@ -161,6 +161,46 @@ If you need the output as a string, you can get the rendered PDF with the output
 
 See the [wkhtmltopdf manual](http://wkhtmltopdf.org/usage/wkhtmltopdf.txt) for more information/settings.
 
+### Testing - PDF fake
+
+As an alternative to mocking, you may use the `PDF` facade's `fake` method. When using fakes, assertions are made after the code under test is executed:
+
+```php
+<?php
+
+namespace Tests\Feature;
+
+use Tests\TestCase;
+use PDF;
+
+class ExampleTest extends TestCase
+{
+    public function testPrintOrderShipping()
+    {
+        PDF::fake();
+
+        // Perform order shipping...
+
+        PDF::assertViewIs('view-pdf-order-shipping');
+        PDF::assertSee('Name');
+    }
+}
+```
+
+#### Other available assertions:
+
+```php
+PDF::assertViewIs($value);
+PDF::assertViewHas($key, $value = null);
+PDF::assertViewHasAll(array $bindings);
+PDF::assertViewMissing($key);
+PDF::assertSee($value);
+PDF::assertSeeText($value);
+PDF::assertDontSee($value);
+PDF::assertDontSeeText($value);
+PDF::assertFileNameIs($value);
+```
+
 ### License
 
 This Snappy Wrapper for Laravel is open-sourced software licensed under the [MIT license](http://opensource.org/licenses/MIT)