fix: handle ambiguous IResponse.getBody return types

Signed-off-by: Daniel Kesselberg <mail@danielkesselberg.de>

build/psalm-baseline.xml

@@ -3943,12 +3943,6 @@
       <code><![CDATA[ArrayCache]]></code>
       <code><![CDATA[ArrayCache]]></code>
     </InvalidClass>
-    <InvalidReturnStatement>
-      <code><![CDATA[$response->getBody()]]></code>
-    </InvalidReturnStatement>
-    <InvalidReturnType>
-      <code><![CDATA[fopen]]></code>
-    </InvalidReturnType>
   </file>
   <file src="lib/private/Files/Storage/Local.php">
     <TypeDoesNotContainNull>
@@ -4197,12 +4191,6 @@
     </ImplementedReturnTypeMismatch>
   </file>
   <file src="lib/private/Remote/Instance.php">
-    <InvalidReturnStatement>
-      <code><![CDATA[$request->getBody()]]></code>
-    </InvalidReturnStatement>
-    <InvalidReturnType>
-      <code><![CDATA[bool|string]]></code>
-    </InvalidReturnType>
     <InvalidScalarArgument>
       <code><![CDATA[$response]]></code>
     </InvalidScalarArgument>

lib/private/Files/Storage/DAV.php

@@ -350,7 +350,13 @@ class DAV extends Common {
 					}
 				}
 
-				return $response->getBody();
+				$content = $response->getBody();
+
+				if ($content === null || is_string($content)) {
+					return false;
+				}
+
+				return $content;
 			case 'w':
 			case 'wb':
 			case 'a':
@@ -390,6 +396,8 @@ class DAV extends Common {
 					$this->writeBack($tmpFile, $path);
 				});
 		}
+
+		return false;
 	}
 
 	public function writeBack(string $tmpFile, string $path): void {

lib/private/Remote/Instance.php

@@ -123,7 +123,13 @@ class Instance implements IInstance {
 	private function downloadStatus($url) {
 		try {
 			$request = $this->clientService->newClient()->get($url);
-			return $request->getBody();
+			$content = $request->getBody();
+
+			// IResponse.getBody responds with null|resource if returning a stream response was requested.
+			// As that's not the case here, we can just ignore the psalm warning by adding an assertion.
+			assert(is_string($content));
+
+			return $content;
 		} catch (\Exception $e) {
 			return false;
 		}

lib/private/Updater/VersionCheck.php

@@ -105,17 +105,20 @@ class VersionCheck {
 	}
 
 	/**
-	 * @codeCoverageIgnore
-	 * @param string $url
-	 * @return resource|string
 	 * @throws \Exception
 	 */
-	protected function getUrlContent($url) {
-		$client = $this->clientService->newClient();
-		$response = $client->get($url, [
+	protected function getUrlContent(string $url): string {
+		$response = $this->clientService->newClient()->get($url, [
 			'timeout' => 5,
 		]);
-		return $response->getBody();
+
+		$content = $response->getBody();
+
+		// IResponse.getBody responds with null|resource if returning a stream response was requested.
+		// As that's not the case here, we can just ignore the psalm warning by adding an assertion.
+		assert(is_string($content));
+
+		return $content;
 	}
 
 	private function computeCategory(): int {