From 8d6cacd808f958abcba45a77aa956cc64b80918e Mon Sep 17 00:00:00 2001
From: Paul Bunkham <paul@dobit.co.uk>
Date: Sat, 27 Aug 2022 19:37:23 +0100
Subject: [PATCH] Metadata: Allow all metadata to be returned for an object

While testing some code that was setting post metadata, I was debugging
it by outputting all the metadata for a post with a call to
`get_post_meta( $post_id )`. I noticed that the tests started passing
but I was still getting an empty array from the `get_post_meta` call.

Getting a specific key was working, which led me to look at the Metadata
code here, which currently doesn't deal with the case of the key being
an empty value.

This change refactors the `get` function, but is probably not optimal,
as we change the shape of the object's metadata using `array_reduce` on
each call. It illustrates the issue, and I'm happy to optimise it if we
want to go this route.
---
 src/Metadata.php | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/src/Metadata.php b/src/Metadata.php
index e6a943a..49f7e28 100644
--- a/src/Metadata.php
+++ b/src/Metadata.php
@@ -70,18 +70,24 @@ public function add( $check, $object_id, $meta_key, $meta_value, $unique ) {
 	}
 
 	public function get( $check, $object_id, $meta_key, $single ) {
-		$check = array();
 		if ( isset( $this->meta[ $object_id ] ) ) {
-			foreach ( $this->meta[ $object_id ] as $meta ) {
-				if ( isset( $meta['meta_key'] ) && $meta_key === $meta['meta_key'] ) {
-					$check[] = maybe_unserialize( $meta['meta_value'] );
-					if ( $single ) {
-						break;
-					}
-				}
+			$obj_meta = array_reduce(
+				$this->meta[ $object_id ],
+				function ( $all_meta, $meta ) {
+					$all_meta[ $meta['meta_key' ] ] = array_merge( $all_meta[ $meta['meta_key'] ] ?? [], [ $meta['meta_value'] ] );
+					return $all_meta;
+				},
+			);
+
+			if ( empty( $meta_key ) ) {
+				return $obj_meta;
+			}
+
+			if ( isset( $obj_meta[ $meta_key ] ) ) {
+				return $single ? array_slice( $obj_meta[ $meta_key ], 0, 1 ) : $obj_meta[ $meta_key ];
 			}
 		}
-		if ( empty( $check ) && $single ) {
+		if ( $single ) {
 			$check = array( '' ); // Ensure an empty string is returned when meta is not found.
 		}
 		return $check;