diff --git a/.mddoc.xml.dist b/.mddoc.xml.dist
index 587c2e0..0e4deb2 100644
--- a/.mddoc.xml.dist
+++ b/.mddoc.xml.dist
@@ -4,7 +4,7 @@
 		<section title="Quorum Array Functions">
 			<badge-poser type="version"/>
 			<badge-poser type="license"/>
-			<badge-github-action name="QuorumCollection/ArrayFunctions" workflow="CI"/>
+			<badge-github-action name="QuorumCollection/ArrayFunctions" workflow-file="ci.yml"/>
 
 			<text>A collection of global `array_*` functions appending to the native PHP set.</text>
 
diff --git a/README.md b/README.md
index a3ae72e..d5c90a9 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 [![Latest Stable Version](https://poser.pugx.org/quorum/array-functions/version)](https://packagist.org/packages/quorum/array-functions)
 [![License](https://poser.pugx.org/quorum/array-functions/license)](https://packagist.org/packages/quorum/array-functions)
-[![CI](https://github.com/QuorumCollection/ArrayFunctions/workflows/CI/badge.svg?)](https://github.com/QuorumCollection/ArrayFunctions/actions?query=workflow%3ACI)
+[![ci.yml](https://github.com/QuorumCollection/ArrayFunctions/actions/workflows/ci.yml/badge.svg)](https://github.com/QuorumCollection/ArrayFunctions/actions/workflows/ci.yml)
 
 
 A collection of global `array_*` functions appending to the native PHP set.
diff --git a/test/ArrayFunctionsTest.php b/test/ArrayFunctionsTest.php
index 7ebb6dd..010b236 100644
--- a/test/ArrayFunctionsTest.php
+++ b/test/ArrayFunctionsTest.php
@@ -18,8 +18,8 @@ public function testArrayFlatten() {
 			array_flatten(array(
 				'bbq' => array(
 					'soda' => array( 1, 2, 4, 'fish fry' ),
-					3
-				)
+					3,
+				),
 			))
 		);
 
@@ -28,27 +28,185 @@ public function testArrayFlatten() {
 			array_flatten(array(
 				'bbq' => array(
 					'soda' => array( 1, 2, 4, 'fish fry' ),
-					3
-				)
+					3,
+				),
 			), true)
 		);
-
 	}
 
 	public function testArrayBlend() {
-		//@todo: I'm not entirely sure how to test this
+		// Test blending arrays without specifying keys
+		$arrays = array(
+			'fruits'     => array( 'apple', 'banana', 'cherry' ),
+			'vegetables' => array( 'carrot', 'broccoli', 'spinach' ),
+			'meats'      => array( 'chicken', 'beef', 'pork' ),
+		);
+
+		$expected = array( 'apple', 'banana', 'cherry', 'carrot', 'broccoli', 'spinach', 'chicken', 'beef', 'pork' );
+		$this->assertEquals($expected, array_blend($arrays));
+
+		// Test blending arrays with specific keys
+		$keys     = array( 'fruits', 'meats' );
+		$expected = array( 'apple', 'banana', 'cherry', 'chicken', 'beef', 'pork' );
+		$this->assertEquals($expected, array_blend($arrays, $keys));
+
+		// Test with empty arrays
+		$arrays = array(
+			'fruits'     => array(),
+			'vegetables' => array( 'carrot', 'broccoli' ),
+			'empty'      => array(),
+		);
+
+		$expected = array( 'carrot', 'broccoli' );
+		$this->assertEquals($expected, array_blend($arrays));
+
+		// Test with non-array values (should be skipped)
+		$arrays = array(
+			'fruits'     => array( 'apple', 'banana' ),
+			'number'     => 42,
+			'vegetables' => array( 'carrot' ),
+		);
+
+		$expected = array( 'apple', 'banana', 'carrot' );
+		$this->assertEquals($expected, array_blend($arrays));
 	}
 
 	public function testArrayKeyArray() {
+		// Test with numeric keys
+		$arrays = array(
+			array( 'id' => 1, 'name' => 'John', 'role' => 'Developer' ),
+			array( 'id' => 2, 'name' => 'Jane', 'role' => 'Designer' ),
+			array( 'id' => 3, 'name' => 'Bob', 'role' => 'Manager' ),
+		);
 
+		$expected = array( 1, 2, 3 );
+		$this->assertEquals($expected, array_key_array($arrays, 'id'));
+
+		// Test with string keys
+		$expected = array( 'John', 'Jane', 'Bob' );
+		$this->assertEquals($expected, array_key_array($arrays, 'name'));
+
+		// Test with associative array keys
+		$arrays = array(
+			'user1' => array( 'id' => 101, 'name' => 'Alice' ),
+			'user2' => array( 'id' => 102, 'name' => 'Charlie' ),
+			'user3' => array( 'id' => 103, 'name' => 'Dave' ),
+		);
+
+		$expected = array( 'user1' => 101, 'user2' => 102, 'user3' => 103 );
+		$this->assertEquals($expected, array_key_array($arrays, 'id'));
+
+		// Test with mixed content
+		$arrays = array(
+			array( 'id' => 201, 'data' => 'value1' ),
+			array( 'id' => 202, 'data' => array( 'nested' => 'value2' ) ),
+			array( 'id' => 203, 'data' => 42 ),
+		);
+
+		$expected = array( 'value1', array( 'nested' => 'value2' ), 42 );
+		$this->assertEquals($expected, array_key_array($arrays, 'data'));
 	}
 
 	public function testArrayKeysArray() {
+		// Test with multiple keys
+		$arrays = array(
+			array( 'id' => 1, 'name' => 'John', 'role' => 'Developer', 'age' => 30 ),
+			array( 'id' => 2, 'name' => 'Jane', 'role' => 'Designer', 'age' => 28 ),
+			array( 'id' => 3, 'name' => 'Bob', 'role' => 'Manager', 'age' => 35 ),
+		);
+
+		$keys     = array( 'id', 'name' );
+		$expected = array(
+			array( 'id' => 1, 'name' => 'John' ),
+			array( 'id' => 2, 'name' => 'Jane' ),
+			array( 'id' => 3, 'name' => 'Bob' ),
+		);
+		$this->assertEquals($expected, array_keys_array($arrays, $keys));
 
+		// Test with a single key (passed as string)
+		$expected = array(
+			array( 'id' => 1 ),
+			array( 'id' => 2 ),
+			array( 'id' => 3 ),
+		);
+		$this->assertEquals($expected, array_keys_array($arrays, 'id'));
+
+		// Test with a single key (passed as array)
+		$this->assertEquals($expected, array_keys_array($arrays, array( 'id' )));
+
+		// Test with associative array keys
+		$arrays = array(
+			'user1' => array( 'id' => 101, 'name' => 'Alice', 'dept' => 'Engineering' ),
+			'user2' => array( 'id' => 102, 'name' => 'Charlie', 'dept' => 'Marketing' ),
+			'user3' => array( 'id' => 103, 'name' => 'Dave', 'dept' => 'Sales' ),
+		);
+
+		$keys     = array( 'id', 'dept' );
+		$expected = array(
+			'user1' => array( 'id' => 101, 'dept' => 'Engineering' ),
+			'user2' => array( 'id' => 102, 'dept' => 'Marketing' ),
+			'user3' => array( 'id' => 103, 'dept' => 'Sales' ),
+		);
+		$this->assertEquals($expected, array_keys_array($arrays, $keys));
 	}
 
 	public function testArrayKeyRefill() {
+		// Test with missing keys and default empty array fill
+		$array = array(
+			'key1' => 'value1',
+			'key3' => 'value3',
+		);
+
+		$keys     = array( 'key1', 'key2', 'key3', 'key4' );
+		$expected = array(
+			'key1' => 'value1',
+			'key2' => array(),
+			'key3' => 'value3',
+			'key4' => array(),
+		);
+
+		$this->assertEquals($expected, array_key_refill($array, $keys));
+
+		// Test with custom fill value (string)
+		$expected = array(
+			'key1' => 'value1',
+			'key2' => 'default',
+			'key3' => 'value3',
+			'key4' => 'default',
+		);
+
+		$this->assertEquals($expected, array_key_refill($array, $keys, 'default'));
+
+		// Test with custom fill value (number)
+		$expected = array(
+			'key1' => 'value1',
+			'key2' => 0,
+			'key3' => 'value3',
+			'key4' => 0,
+		);
+
+		$this->assertEquals($expected, array_key_refill($array, $keys, 0));
+
+		// Test with custom fill value (array)
+		$fillArray = array( 'status' => 'empty' );
+		$expected  = array(
+			'key1' => 'value1',
+			'key2' => $fillArray,
+			'key3' => 'value3',
+			'key4' => $fillArray,
+		);
+
+		$this->assertEquals($expected, array_key_refill($array, $keys, $fillArray));
+
+		// Test with no missing keys
+		$array = array(
+			'a' => 1,
+			'b' => 2,
+			'c' => 3,
+		);
 
+		$keys = array( 'a', 'b', 'c' );
+		$this->assertEquals($array, array_key_refill($array, $keys, 'unused'));
 	}