diff --git a/src/Argument/ShortOptionArgument.php b/src/Argument/ShortOptionArgument.php
index 9d3ff29..230ffa1 100644
--- a/src/Argument/ShortOptionArgument.php
+++ b/src/Argument/ShortOptionArgument.php
@@ -3,6 +3,13 @@
 
 class ShortOptionArgument extends Argument {
 	protected function processRawKey(string $rawKey):string {
-		return substr($rawKey, 1);
+		$key = substr($rawKey, 1);
+		$equalsPos = strpos($key, "=");
+
+		if($equalsPos !== false) {
+			$key = substr($key, 0, $equalsPos);
+		}
+
+		return $key;
 	}
 }
\ No newline at end of file
diff --git a/test/unit/ArgumentListTest.php b/test/unit/ArgumentListTest.php
index 4606f30..0ee7ff9 100644
--- a/test/unit/ArgumentListTest.php
+++ b/test/unit/ArgumentListTest.php
@@ -1,20 +1,309 @@
 <?php
 namespace Gt\Cli\Test;
 
+use Gt\Cli\Argument\Argument;
 use Gt\Cli\Argument\ArgumentList;
+use Gt\Cli\Parameter\Parameter;
+use phpDocumentor\Reflection\DocBlock\Tags\Param;
 use PHPUnit\Framework\TestCase;
 
 class ArgumentListTest extends TestCase {
-	/** @dataProvider data_randomArgs */
+	/** @dataProvider data_randomNamedArgs */
 	public function testGetCommandName(string...$args) {
 		$argumentList = new ArgumentList(
 			array_shift($args),
 			...$args
 		);
+		self::assertEquals(
+			$args[0],
+			$argumentList->getCommandName()
+		);
+	}
+
+	/** @dataProvider data_randomNamedArgs */
+	public function testIteratorWithNamedArgs(string...$args) {
+		$argumentList = new ArgumentList(
+			array_shift($args),
+			...$args
+		);
+
+		foreach($argumentList as $i => $argument) {
+			/** @var Argument $argument */
+			self::assertInstanceOf(
+				Argument::class,
+				$argument
+			);
+
+			self::assertEquals(
+				$args[$i],
+				$argument
+			);
+		}
+	}
+
+	/** @dataProvider data_randomLongArgs */
+	public function testIteratorWithLongArgs(string...$args) {
+		$argumentList = new ArgumentList(
+			array_shift($args),
+			...$args
+		);
+
+		foreach($argumentList as $i => $argument) {
+			/** @var Argument $argument */
+			self::assertInstanceOf(
+				Argument::class,
+				$argument
+			);
+
+			if($i === 0) {
+				self::assertEquals(
+					$args[0],
+					$argument
+				);
+				continue;
+			}
+
+			$originalKey = $args[($i - 1) * 2 + 1];
+			$originalValue = $args[($i - 1) * 2 + 2];
+
+			self::assertEquals(
+				substr($originalKey, 2),
+				$argument->getKey()
+			);
+			self::assertEquals(
+				$originalValue,
+				$argument->getValue()
+			);
+		}
+	}
+
+	/** @dataProvider data_randomShortArgs */
+	public function testIteratorWithShortArgs(string...$args) {
+		$argumentList = new ArgumentList(
+			array_shift($args),
+			...$args
+		);
+
+		foreach($argumentList as $i => $argument) {
+			/** @var Argument $argument */
+			self::assertInstanceOf(
+				Argument::class,
+				$argument
+			);
+
+			if($i === 0) {
+				self::assertEquals(
+					$args[0],
+					$argument
+				);
+				continue;
+			}
+
+			$originalKey = $args[($i - 1) * 2 + 1];
+			$originalValue = $args[($i - 1) * 2 + 2];
+
+			self::assertEquals(
+				substr($originalKey, 1),
+				$argument->getKey()
+			);
+			self::assertEquals(
+				$originalValue,
+				$argument->getValue()
+			);
+		}
+	}
+
+	/** @dataProvider data_randomShortArgs */
+	public function testContainsWithShortArgs(string...$args) {
+		$argumentList = new ArgumentList(
+			array_shift($args),
+			...$args
+		);
+
+		foreach($args as $i => $arg) {
+			if($i === 0) {
+				continue;
+			}
+
+			if($i % 2 === 0) {
+// Because args are passed in as "--key value" every other original arg is skipped.
+				continue;
+			}
+
+			$param = self::createMock(Parameter::class);
+			$param->method("getShortOption")
+				->willReturn(substr($arg, 1));
+
+			/** @var Parameter $param */
+			self::assertTrue($argumentList->contains($param));
+		}
+	}
+
+	/** @dataProvider data_randomLongArgs */
+	public function testContainsWithLongArgs(string...$args) {
+		$argumentList = new ArgumentList(
+			array_shift($args),
+			...$args
+		);
+
+		foreach($args as $i => $arg) {
+			if($i === 0) {
+				continue;
+			}
+
+			if($i % 2 === 0) {
+// Because args are passed in as "--key value" every other original arg is skipped.
+				continue;
+			}
+
+			$param = self::createMock(Parameter::class);
+			$param->method("getLongOption")
+				->willReturn(substr($arg, 2));
+
+			/** @var Parameter $param */
+			self::assertTrue($argumentList->contains($param));
+		}
+	}
+
+	/** @dataProvider data_randomLongArgs */
+	public function testNotContains(string...$args) {
+		$argumentList = new ArgumentList(
+			array_shift($args),
+			...$args
+		);
+
+		foreach($args as $i => $arg) {
+			if($i === 0) {
+				continue;
+			}
+
+			if($i % 2 === 0) {
+// Because args are passed in as "--key value" every other original arg is skipped.
+				continue;
+			}
+
+			$param = self::createMock(Parameter::class);
+			$param->method("getLongOption")
+				->willReturn(uniqid());
+
+			/** @var Parameter $param */
+			self::assertFalse($argumentList->contains($param));
+		}
+	}
+
+	/** @dataProvider data_randomLongEqualsArgs */
+	public function testKeyValueSetWithLongOptionEqualsSign(string...$args) {
+		$argumentList = new ArgumentList(
+			array_shift($args),
+			...$args
+		);
+
+		foreach($args as $i => $arg) {
+			if($i === 0) {
+				continue;
+			}
+
+			$arg = substr($arg, 2);
+			list($key, $value) = explode("=", $arg);
+
+			$param = self::createMock(Parameter::class);
+			$param->method("getLongOption")
+				->willReturn($key);
+
+			self::assertEquals(
+				$value,
+				$argumentList->getValueForParameter($param)
+			);
+		}
+	}
+
+	/** @dataProvider data_randomShortEqualsArgs */
+	public function testKeyValueSetWithShortOptionEqualsSign(string...$args) {
+		$argumentList = new ArgumentList(
+			array_shift($args),
+			...$args
+		);
+
+		foreach($args as $i => $arg) {
+			if($i === 0) {
+				continue;
+			}
+
+			$arg = substr($arg, 1);
+			list($key, $value) = explode("=", $arg);
+
+			$param = self::createMock(Parameter::class);
+			$param->method("getShortOption")
+				->willReturn($key);
+
+			$paramValue = $argumentList->getValueForParameter($param);
+
+			if($paramValue != $value) {
+
+				var_dump($args);die();
+			}
+
+			self::assertEquals(
+				$value,
+				$paramValue
+			);
+		}
+	}
+
+	/** @dataProvider data_randomShortEqualsArgs */
+	public function testGetValueForParameterNotExists(string...$args) {
+		$argumentList = new ArgumentList(
+			array_shift($args),
+			...$args
+		);
+
+		foreach($args as $i => $arg) {
+			if($i === 0) {
+				continue;
+			}
+
+			$arg = substr($arg, 1);
+			list($key, $value) = explode("=", $arg);
+
+			$param = self::createMock(Parameter::class);
+			$param->method("getShortOption")
+				->willReturn("Z");
+
+			self::assertNull($argumentList->getValueForParameter($param));
+		}
+	}
+
+	/** @dataProvider data_randomLongArgs */
+	public function testGetValueForParameterWithLongOption(string...$args) {
+		$argumentList = new ArgumentList(
+			array_Shift($args),
+			...$args
+		);
+
+		$param = self::createMock(Parameter::class);
+		$param->method("getLongOption")
+			->willReturn(substr($args[1], 2));
+		$value = $argumentList->getValueForParameter($param);
+
+		self::assertEquals($args[2], $value);
+	}
+
+	/** @dataProvider data_randomShortArgs */
+	public function testGetValueParameterWithShortOption(string...$args) {
+		$argumentList = new ArgumentList(
+			array_shift($args),
+			...$args
+		);
+
+		$param = self::createMock(Parameter::class);
+		$param->method("getShortOption")
+			->willReturn(substr($args[1], 1));
+		$value = $argumentList->getValueForParameter($param);
 
+		self::assertEquals($args[2], $value);
 	}
 
-	public function data_randomArgs():array {
+	public function data_randomNamedArgs():array {
 		$dataSet = [];
 
 		for($i = 0; $i < 10; $i++) {
@@ -33,4 +322,100 @@ public function data_randomArgs():array {
 
 		return $dataSet;
 	}
+
+	public function data_randomLongArgs():array {
+		$dataSet = [];
+
+		for($i = 0; $i < 10; $i++) {
+			$params = [];
+
+			$params []= uniqid("script-");
+			$params []= uniqid("command-");
+
+			$numParams = rand(1, 10);
+			for($j = 0; $j < $numParams; $j++) {
+				if($j % 2 === 0) {
+					$params []= "--" . uniqid();
+				}
+				else {
+					$params []= uniqid();
+				}
+			}
+
+			$dataSet []= $params;
+		}
+
+		return $dataSet;
+	}
+
+	public function data_randomShortArgs():array {
+		$dataSet = [];
+
+		for($i = 0; $i < 10; $i++) {
+			$params = [];
+
+			$params []= uniqid("script-");
+			$params []= uniqid("command-");
+
+			$numParams = rand(1, 10);
+			for($j = 0; $j < $numParams; $j++) {
+				if($j % 2 === 0) {
+					$params []= "-" . uniqid();
+				}
+				else {
+					$params []= uniqid();
+				}
+			}
+
+			$dataSet []= $params;
+		}
+
+		return $dataSet;
+	}
+
+	public function data_randomLongEqualsArgs():array {
+		$dataSet = [];
+
+		for($i = 0; $i < 10; $i++) {
+			$params = [];
+
+			$params []= uniqid("script-");
+			$params []= uniqid("command-");
+
+			$numParams = rand(1, 10);
+			for($j = 0; $j < $numParams; $j++) {
+				$params []= "--" . uniqid() . "=" . uniqid();
+			}
+
+			$dataSet []= $params;
+		}
+
+		return $dataSet;
+	}
+
+	public function data_randomShortEqualsArgs():array {
+		$dataSet = [];
+
+		for($i = 0; $i < 10; $i++) {
+			$charArray = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"];
+			$params = [];
+
+			$params []= uniqid("script-");
+			$params []= uniqid("command-");
+
+			$numParams = rand(1, 10);
+			for($j = 0; $j < $numParams; $j++) {
+				$char = array_shift($charArray);
+
+				$params []= "-"
+					. $char
+					. "="
+					. uniqid();
+			}
+
+			$dataSet []= $params;
+		}
+
+		return $dataSet;
+	}
 }
\ No newline at end of file