Adds and implements QueryAuthException interface

src/QueryAuth/Exception/QueryAuthException.php

@@ -0,0 +1,12 @@
+<?php
+/**
+ * Query Auth: Signature generation and validation for REST API query authentication
+ *
+ * @copyright 2013 Jeremy Kendall
+ * @license https://github.com/jeremykendall/query-auth/blob/master/LICENSE MIT
+ * @link https://github.com/jeremykendall/query-auth
+ */
+
+namespace QueryAuth\Exception;
+
+interface QueryAuthException {}

src/QueryAuth/Exception/SignatureMissingException.php

@@ -12,6 +12,6 @@
 /**
  * Exception thrown when Signature is missing
  */
-class SignatureMissingException extends \Exception
+class SignatureMissingException extends \Exception implements QueryAuthException
 {
 }

src/QueryAuth/Exception/TimeOutOfBoundsException.php

@@ -12,6 +12,6 @@
 /**
  * Thrown when request timestamp is beyond allowable clock drift
  */
-class TimeOutOfBoundsException extends \OutOfBoundsException
+class TimeOutOfBoundsException extends \OutOfBoundsException implements QueryAuthException
 {
 }

tests/QueryAuth/Tests/Exception/QueryAuthExceptionTest.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace QueryAuth\Tests;
+
+use QueryAuth\Exception\QueryAuthException;
+use QueryAuth\Exception\SignatureMissingException;
+use QueryAuth\Exception\TimeOutOfBoundsException;
+
+class QueryAuthExceptionTest extends \PHPUnit_Framework_TestCase
+{
+    public function testSignatureMissingException()
+    {
+        $e = new SignatureMissingException();
+        $this->assertInstanceOf('QueryAuth\Exception\SignatureMissingException', $e);
+        $this->assertInstanceOf('QueryAuth\Exception\QueryAuthException', $e);
+    }
+
+    public function testTimeOutOfBoundsException()
+    {
+        $e = new TimeOutOfBoundsException();
+        $this->assertInstanceOf('QueryAuth\Exception\TimeOutOfBoundsException', $e);
+        $this->assertInstanceOf('QueryAuth\Exception\QueryAuthException', $e);
+    }
+}