[11.x] Make Cache::forget compatible with Cache::flexible

[rbadillap]

Fixes #52847

Current Behavior

The Cache::flexible method, which implements the "stale-while-revalidate" pattern, currently creates two cache items:

• The main item with the given key
• A metadata item with the key + ":created" suffix

When Cache::forget is called, it only removes the main item, leaving the metadata item in place. This leads to unexpected behavior in the cache lifecycle.

The issue

When Cache::forget is called, it only removes the main item, leaving the ":created" timestamp intact.
On the next request, Cache::flexible finds a null value for the main item but an existing ":created" timestamp.

This causes the method to incorrectly assume the item is in the stale or expired state, rather than treating it as a fresh cache miss.

As a result, the cache remains null until the stale period is over, effectively breaking the expected cache regeneration behavior.

Current behavior

current_behavior.mov

Expected behavior

expected_behavior.mov

Proposed Fix

Update the Cache::forget method to remove both the main item and the associated metadata item when called on a key created by Cache::flexible.

PoC

My PoC if you want to interactively test the issue.

<?php

use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Route;

Route::get('/debug', function () {

    $cachedAt = Cache::flexible('current-time', [5, 10], function () {
        $start = microtime(true);
        $when = now()->toTimeString();
        sleep(2);

        $end = microtime(true);
        $executionTime = ($end - $start) * 1000;
        return [
            "when" => $when,
            'execution_time_ms' => round($executionTime, 2),
        ];
    });

    $mainItem = Cache::get('current-time');
    $createdItem = Cache::get('current-time:created');


    return response()->json([
        'status' => 'ok',
        'cached_at' => $cachedAt,
        'current_time' => now()->toTimeString(),
        'cache_state' => [
            'main_item' => $mainItem,
            'created_item' => $createdItem,
        ],
    ]);
});

Route::get('/refresh', function () {
    $beforeForget = [
        'main_item' => Cache::get('current-time'),
        'created_item' => Cache::get('current-time:created'),
    ];

    Cache::forget('current-time');

    $afterForget = [
        'main_item' => Cache::get('current-time'),
        'created_item' => Cache::get('current-time:created'),
    ];

    return response()->json([
        'status' => 'ok',
        'message' => 'Cache forcefully refreshed',
        'time' => now()->toTimeString(),
        'cache_state_before_forget' => $beforeForget,
        'cache_state_after_forget' => $afterForget,
    ]);
});

Route::get('/force-refresh', function () {
    $beforeForget = [
        'main_item' => Cache::get('current-time'),
        'created_item' => Cache::get('current-time:created'),
    ];

    Cache::forget('current-time');
    Cache::forget('current-time:created');

    $afterForget = [
        'main_item' => Cache::get('current-time'),
        'created_item' => Cache::get('current-time:created'),
    ];

    return response()->json([
        'status' => 'ok',
        'message' => 'Cache forcefully refreshed',
        'time' => now()->toTimeString(),
        'cache_state_before' => $beforeForget,
        'cache_state_after' => $afterForget,
    ]);
});

[github-actions]

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[rbadillap]

Just noticed this PR fixes #52847

[timacdonald]

Marking this one as draft while we discuss it internally.

[timacdonald]

I've opened another PR to address this issue: #52891

Thanks for letting us know about the problem.