diff --git a/.gitignore b/.gitignore
index 910c0ff1..f03762d1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,4 +21,5 @@ src-tmp/
 .phpunit.result.cache
 ./qit
 _tests/**/*.zip
-_tests/**/*.txt
\ No newline at end of file
+_tests/**/*.txt
+dev/
\ No newline at end of file
diff --git a/qit b/qit
index 0c1f100a..22164073 100755
Binary files a/qit and b/qit differ
diff --git a/src/src/Config.php b/src/src/Config.php
index b97e2358..f4a4443d 100644
--- a/src/src/Config.php
+++ b/src/src/Config.php
@@ -166,56 +166,42 @@ public static function get_qit_dir(): string {
 
 		// Allow override.
 		if ( ! empty( getenv( 'QIT_HOME' ) ) ) {
-			if ( ! file_exists( getenv( 'QIT_HOME' ) ) ) {
-				throw new \RuntimeException( sprintf( 'The QIT_HOME environment variable is defined, but points to a non-existing directory: %s', getenv( 'QIT_CLI_CONFIG_DIR' ) ) );
-			}
-
-			return $normalize_path( getenv( 'QIT_HOME' ) );
-		}
-
-		// Windows.
-		if ( is_windows() ) {
+			$parent_config_dir = getenv( 'QIT_HOME' );
+		} elseif ( is_windows() ) {
 			if ( empty( getenv( 'APPDATA' ) ) ) {
-				throw new \RuntimeException( 'The APPDATA or QIT_HOME environment variables must be defined.' );
+				throw new \RuntimeException( 'The APPDATA or QIT_HOME environment variables must be defined in Windows.' );
 			}
-
-			return $normalize_path( getenv( 'APPDATA' ) ) . 'woo-qit-cli';
-		}
-
-		if ( empty( getenv( 'HOME' ) ) ) {
-			throw new \RuntimeException( 'The HOME or QIT_HOME environment variables must be defined.' );
-		}
-
-		$home = $normalize_path( getenv( 'HOME' ) );
-		$dirs = [];
-
-		if ( static::use_xdg() ) {
-			$xdg_config = getenv( 'XDG_CONFIG_HOME' );
-			if ( ! $xdg_config ) {
-				$xdg_config = $home . '.config';
+			$parent_config_dir = getenv( 'APPDATA' );
+		} elseif ( ! empty( getenv( 'HOME' ) ) ) {
+			$home = $normalize_path( getenv( 'HOME' ) );
+			if ( static::use_xdg() ) {
+				$xdg_config        = getenv( 'XDG_CONFIG_HOME' ) ?: $home . '.config';
+				$parent_config_dir = $xdg_config;
+			} else {
+				$parent_config_dir = $home;
 			}
-
-			$dirs[] = $xdg_config . '/woo-qit-cli/';
+		} else {
+			throw new \RuntimeException( 'The HOME, APPDATA, or QIT_HOME environment variables must be defined.' );
 		}
 
-		$dirs[] = $home . 'woo-qit-cli/';
-
-		foreach ( $dirs as $dir ) {
-			if ( is_dir( $dir ) ) {
-				return $dir;
-			}
+		// Normalize and append 'woo-qit-cli/' to the parent directory.
+		$qit_dir = $normalize_path( $parent_config_dir ) . 'woo-qit-cli/';
 
-			$dir_created = mkdir( $dir, 0700, true );
-
-			if ( $dir_created ) {
-				return $dir;
-			}
+		// Create the directory if it does not exist.
+		if ( ! is_dir( $qit_dir ) && ! mkdir( $qit_dir, 0700, true ) ) {
+			throw new \RuntimeException( "Unable to create the QIT CLI directory: $qit_dir" );
 		}
 
-		throw new \RuntimeException( "You need to set an environment variable 'QIT_HOME' pointing to a writable directory where the QIT CLI can write it's config file. Do NOT use a directory inside your plugin, as the config file will hold sensitive information that should not be included in your plugin." );
+		return $qit_dir;
 	}
 
+
 	protected static function use_xdg(): bool {
+		if ( defined( 'UNIT_TESTS' ) && UNIT_TESTS ) {
+			if ( App::getVar( 'MIMICK_XDG' ) ) {
+				return true;
+			}
+		}
 		foreach ( array_keys( $_SERVER ) as $key ) {
 			if ( strpos( $key, 'XDG_' ) === 0 ) {
 				return true;
diff --git a/src/src/helpers.php b/src/src/helpers.php
index 9c9a576a..ed27292e 100644
--- a/src/src/helpers.php
+++ b/src/src/helpers.php
@@ -3,6 +3,11 @@
 namespace QIT_CLI;
 
 function is_windows(): bool {
+	if ( defined( 'UNIT_TESTS' ) && UNIT_TESTS ) {
+		if ( App::getVar( 'MIMICK_WINDOWS' ) ) {
+			return true;
+		}
+	}
 	return defined( 'PHP_WINDOWS_VERSION_BUILD' );
 }
 
diff --git a/src/tests/ConfigTest.php b/src/tests/ConfigTest.php
new file mode 100644
index 00000000..bea0db26
--- /dev/null
+++ b/src/tests/ConfigTest.php
@@ -0,0 +1,110 @@
+<?php
+
+use PHPUnit\Framework\TestCase;
+use QIT_CLI\App;
+use QIT_CLI\Config;
+
+class ConfigTest extends TestCase {
+	private $testDir;
+	private static $originalEnvVars;
+
+	protected function setUp(): void {
+		if ( is_null( static::$originalEnvVars ) ) {
+			static::$originalEnvVars = [
+				'QIT_HOME'        => getenv( 'QIT_HOME' ),
+				'APPDATA'         => getenv( 'APPDATA' ),
+				'HOME'            => getenv( 'HOME' ),
+				'XDG_CONFIG_HOME' => getenv( 'XDG_CONFIG_HOME' ),
+			];
+		}
+
+		// Reset environment variables to a default state for testing.
+		putenv( 'QIT_HOME=' );
+		putenv( 'APPDATA=' );
+		putenv( 'HOME=' );
+		putenv( 'XDG_CONFIG_HOME=' );
+
+		$this->testDir = __DIR__ . '/data/config/';
+	}
+
+	protected function tearDown(): void {
+		// Restore original environment variables.
+		foreach ( static::$originalEnvVars as $var => $value ) {
+			if ( $value === false ) {
+				putenv( $var );
+			} else {
+				putenv( "$var=$value" );
+			}
+		}
+		App::offsetUnset( 'MIMICK_WINDOWS' );
+		App::offsetUnset( 'MIMICK_XDG' );
+	}
+
+	public function test_get_qit_dir_with_qit_home_override(): void {
+		$expectedDir = $this->testDir . 'woo-qit-cli/';
+
+		foreach ( [ 'windows', 'unix' ] as $os ) {
+			if ( $os === 'windows' ) {
+				App::setVar( 'MIMICK_WINDOWS', true );
+			} else {
+				App::offsetUnset( 'MIMICK_WINDOWS' );
+			}
+
+			// Regular.
+			putenv( 'QIT_HOME=' . $this->testDir );
+			$this->assertEquals( $expectedDir, Config::get_qit_dir() );
+
+			// Missing trailing slash.
+			putenv( 'QIT_HOME=' . rtrim( $this->testDir, '/' ) );
+			$this->assertEquals( $expectedDir, Config::get_qit_dir() );
+
+			// Windows directory separator - Non windows.
+			putenv( 'QIT_HOME=' . str_replace( '/', '\\', $this->testDir ) );
+			$this->assertEquals( $expectedDir, Config::get_qit_dir() );
+
+			// Windows directory separator missing trailing slash - Non windows.
+			putenv( 'QIT_HOME=' . rtrim( str_replace( '/', '\\', $this->testDir ), '\\' ) );
+			$this->assertEquals( $expectedDir, Config::get_qit_dir() );
+		}
+	}
+
+	public function test_get_qit_dir_on_windows(): void {
+		App::setVar( 'MIMICK_WINDOWS', true );
+
+		putenv( 'APPDATA=' . $this->testDir );
+		$expectedDir = $this->testDir . 'woo-qit-cli/';
+		$this->assertEquals( $expectedDir, Config::get_qit_dir() );
+
+		// Simulate Windows environment
+		putenv( 'APPDATA=' . str_replace( '/', '\\', $this->testDir ) );
+		$this->assertEquals( $expectedDir, Config::get_qit_dir() );
+	}
+
+	public function test_get_qit_dir_with_home(): void {
+		putenv( 'HOME=' . $this->testDir );
+		$expectedDir = $this->testDir . 'woo-qit-cli/';
+		$this->assertEquals( $expectedDir, Config::get_qit_dir() );
+
+		// Simulate Windows separator.
+		putenv( 'HOME=' . str_replace( '/', '\\', $this->testDir ) );
+		$this->assertEquals( $expectedDir, Config::get_qit_dir() );
+	}
+
+	public function test_get_qit_dir_with_home_and_xdg(): void {
+		putenv( 'HOME=' . $this->testDir );
+		putenv( 'XDG_CONFIG_HOME=' . $this->testDir . '.config' );
+		App::setVar( 'MIMICK_XDG', true );
+		$expectedDir = $this->testDir . '.config/woo-qit-cli/';
+		$this->assertEquals( $expectedDir, Config::get_qit_dir() );
+	}
+
+	public function test_get_qit_dir_throws_if_needed(): void {
+		putenv( 'QIT_HOME' );
+		putenv( 'APPDATA' );
+		putenv( 'HOME' );
+		putenv( 'XDG_CONFIG_HOME' );
+
+		$this->expectException( \RuntimeException::class );
+		Config::get_qit_dir();
+	}
+}