Merge branch '7-logout'

# Conflicts:
#	src/Authenticator.php
#	src/ProviderUri/LogoutUri.php
#	test/phpunit/AuthenticatorTest.php

Author: Greg Bowler

src/Authenticator.php

@@ -111,8 +111,12 @@ public function getAdminUri(
 		);
 	}
 
-	public function getLogoutUri():UriInterface {
-		return new LogoutUri($this->authwaveHost);
+	public function getLogoutUri(string $returnToPath = null):UriInterface {
+		if(is_null($returnToPath)) {
+			$returnToPath = $this->currentUriPath;
+		}
+
+		return new LogoutUri($this->authwaveHost, $returnToPath);
 	}
 
 	private function completeAuth():void {

src/ProviderUri/LogoutUri.php

@@ -4,9 +4,15 @@
 class LogoutUri extends AbstractProviderUri {
 	const PATH_LOGOUT = "/logout";
 
-	public function __construct(string $baseRemoteUri) {
+	public function __construct(
+		string $baseRemoteUri,
+		string $returnToUri = "/"
+	) {
 		$baseRemoteUri = $this->normaliseBaseUri($baseRemoteUri);
 		parent::__construct($baseRemoteUri);
 		$this->path = self::PATH_LOGOUT;
+		$this->query = http_build_query([
+			"returnTo" => $returnToUri,
+		]);
 	}
 }

test/phpunit/AuthenticatorTest.php

@@ -73,24 +73,42 @@ public function testLogoutClearsSession() {
 			Authenticator::SESSION_KEY => $sessionData
 		];
 
+		$redirectHandler = self::createMock(RedirectHandler::class);
+
+		$sut = new Authenticator(
+			"example-app-id",
+			"test-key",
+			"/",
+			AuthUri::DEFAULT_BASE_REMOTE_URI,
+			null,
+			$redirectHandler
+		);
+		$sut->logout();
+		self::assertEmpty($_SESSION);
+	}
+
+	public function testLogoutRedirectsToCurrentPath() {
+		$_SESSION = [];
+		$currentPath = "/current/example/path";
+
 		$redirectHandler = self::createMock(RedirectHandler::class);
 		$redirectHandler->expects(self::once())
 			->method("redirect")
 			->with(self::callback(fn(UriInterface $uri) =>
 				$uri->getHost() === AuthUri::DEFAULT_BASE_REMOTE_URI
 				&& $uri->getPath() === LogoutUri::PATH_LOGOUT
+				&& $uri->getQuery() === "returnTo=" . urlencode($currentPath)
 			));
 
 		$sut = new Authenticator(
 			"example-app-id",
 			"test-key",
-			"/",
+			$currentPath,
 			AuthUri::DEFAULT_BASE_REMOTE_URI,
 			null,
 			$redirectHandler
 		);
 		$sut->logout();
-		self::assertEmpty($_SESSION);
 	}
 
 	public function testLoginRedirects() {