update readme

Author: johanrosenson

README.md

@@ -5,12 +5,63 @@
 
 # PHPUnit Exception Assertions
 
-...
+Trait containing assertions for easier testing of thrown (or not thrown) exceptions.
 
 # Installation
 
-...
+```bash
+composer require --dev devlop/phpunit-exception-assertions
+```
 
 # Usage
 
-...
+Include the trait to get access to the assertions.
+
+```php
+use Devlop\PHPUnit\ExceptionAssertions;
+
+class YourTest extends TestCase
+{
+    use ExceptionAssertions;
+}
+```
+
+# Available Assertions
+
+## assertExceptionThrown
+
+Asserts that a specific exception was thrown during the execution of the callback,
+if the callback finishes without the exception being thrown, the assertion fails.
+
+To check for any exception, use `\Throwable::class` as first argument since all exceptions inherits from [`\Throwable`](https://www.php.net/manual/en/class.throwable.php).
+
+```php
+$this->assertExceptionThrown(\InvalidArgumentException::class, function () : void {
+    // code that should throw the expected exception
+});
+```
+
+## assertNoExceptionsThrown
+
+Asserts that no exceptions was thrown during the execution of the callback,
+if any exceptions was thrown during the execution the assertion fails.
+
+```php
+$this->assertNoExceptionsThrown(function () : void {
+    // code that should not throw any exceptions
+});
+```
+
+## assertExceptionNotThrown
+
+Asserts that a specific exception was not thrown during the execution of the callback,
+if the specified exception was thrown during execution the assertion fails.
+
+**use with caution** - this will only assert that a specific exception was not thrown and
+the assertion will pass for any other exceptions thrown, intentional or accidental.
+
+```php
+$this->assertExceptionNotThrown(\InvalidArgumentException::class, function () : void {
+    // code that should not throw the exception
+});
+```