Let jsonSerialize have a proper return type

Signed-off-by: Julius Härtl <jus@bitgrid.net>

3 files changed, 3 insertions, 6 deletions

diff --git a/lib/Db/Document.php b/lib/Db/Document.php
index ae3dd43ad..65c8e1986 100644
--- a/lib/Db/Document.php
+++ b/lib/Db/Document.php
@@ -42,7 +42,7 @@ class Document extends Entity implements \JsonSerializable {
 		$this->addType('initialVersion', 'integer');
 	}
 
-	public function jsonSerialize() {
+	public function jsonSerialize(): array {
 		return [
 			'id' => $this->id,
 			'currentVersion' => $this->currentVersion,
diff --git a/lib/Db/Session.php b/lib/Db/Session.php
index 3dc775ed7..34d518aed 100644
--- a/lib/Db/Session.php
+++ b/lib/Db/Session.php
@@ -47,7 +47,7 @@ class Session extends Entity implements \JsonSerializable {
 		$this->addType('lastContact', 'integer');
 	}
 
-	public function jsonSerialize() {
+	public function jsonSerialize(): array {
 		return [
 			'id' => $this->id,
 			'userId' => $this->userId,
diff --git a/lib/Db/Step.php b/lib/Db/Step.php
index efc1676fb..fec0537bd 100644
--- a/lib/Db/Step.php
+++ b/lib/Db/Step.php
@@ -39,10 +39,7 @@ class Step extends Entity implements \JsonSerializable {
 		$this->addType('sessionId', 'integer');
 	}
 
-	/**
-	 * @return array|mixed
-	 */
-	public function jsonSerialize() {
+	public function jsonSerialize(): array {
 		$jsonData = \json_decode($this->data, false);
 		if (\json_last_error() !== JSON_ERROR_NONE) {
 			throw new \InvalidArgumentException('Failed to parse step data');