Feature/8103 add settings changes detection

[Miraeld]

Description

Fixes #8103
This pull request introduces a new mechanism to automatically refresh performance recommendations when relevant WP Rocket settings change. It ensures that recommendations are only fetched when necessary, based on changes to key options or metrics, and adds robust unit and integration tests for this logic. The most important changes are as follows:

Type of change

• New feature (non-breaking change which adds functionality).

Detailed scenario

What was tested

Automated Tests (✅ Passing):

• Unit tests for SettingsSubscriber::maybe_fetch_after_settings_change() - 8 scenarios covering all status conditions (pending, loading, completed, failed), relevant vs irrelevant changes, and hash-based optimization
• Unit tests for SettingsSubscriber::get_subscribed_events() - Verifies hook registration with correct parameters
• Unit tests for DataManager::has_required_metrics() - 6 scenarios covering all core metrics (LCP, TTFB, CLS, TBT) validation
• Integration tests for settings change detection with WordPress hooks and transient operations

Manual Tests (Recommended):

1. Relevant Setting Change Triggers Fetch - Toggle "Minify CSS" → Save → Verify new recommendations fetched
2. Irrelevant Setting Change Does NOT Trigger - Change "Cache Lifespan" → Save → Verify no fetch occurs
3. No Fetch When Status Pending - Clear recommendations transient → Change setting → No fetch until status is completed
4. Multiple Settings Changed - Toggle multiple options at once → Single fetch triggered
5. Hash Unchanged Prevention - Save same settings twice → Second save doesn't trigger redundant fetch

How to test

Prerequisites:

1. Enable Rocket Insights with active license
2. Ensure Global Score is completed (status = "completed") - Visit Dashboard → Rocket Insights, test at least one URL
3. Optional: Enable WP_DEBUG_LOG to monitor log entries in /wp-content/debug.log

Test 1: Relevant Setting Change Triggers Fetch

Steps:

1. Go to Settings → WP Rocket → File Optimization
2. Toggle Minify CSS files (OFF → ON or ON → OFF)
3. Click Save Changes

Expected:

• Settings save successfully
• New recommendations are fetched from API
• Transient wpr_ri_recommendations updated with new metrics_hash
• Log shows: "Recommendations: Relevant settings changed, fetching new recommendations"

Test 2: Irrelevant Setting Change Does NOT Trigger Fetch

Steps:

1. Go to Settings → WP Rocket → Advanced Rules
2. Change Cache Lifespan (e.g., 10h → 20h)
3. Click Save Changes

Expected:

• Settings save successfully
• NO fetch occurs
• Log shows: "Recommendations: Settings changed but none affect recommendations"

Test 3: Multiple Relevant Settings at Once

Steps:

1. Go to Settings → WP Rocket → File Optimization
2. Change multiple settings: Enable Minify CSS, Minify JavaScript, Combine JavaScript
3. Click Save Changes

Expected:

• Single fetch triggered (not multiple)
• New recommendations reflect all changes

Monitored Settings (21 total):

• Minify CSS/JS, Combine CSS/JS, Defer JS, Delay JS, Async CSS, Critical CSS, Remove Unused CSS
• LazyLoad (Images, Iframes, YouTube), Image Dimensions
• CDN, Mobile Cache, Cache Logged Users, WebP Cache
• Manual Preload, Sitemap Preload, Heartbeat Control, Google Fonts

Verification Methods:

# Check transient via WP-CLI
wp transient get wpr_ri_recommendations

# Check for metrics_hash field
wp transient get wpr_ri_recommendations | jq .metrics_hash

# Monitor logs (if WP_DEBUG_LOG enabled)
tail -f wp-content/debug.log | grep "Recommendations:"

Affected Features & Quality Assurance Scope

Primary Feature:

• Rocket Insights → Recommendations System
• Settings change detection and automatic recommendations refresh

Technical description

Documentation

Feature: Automatic Recommendations Refresh on Settings Change

• Added a new SettingsSubscriber class that listens for changes to WP Rocket settings and triggers a recommendations refresh only if relevant settings are changed and the underlying metrics hash differs, preventing unnecessary API calls.
• Registered the new subscriber in the service provider and plugin initialization to ensure it is loaded and active in the application lifecycle. [1] [2] [3] [4]

Enhancement: Metrics and Hash Validation

• Added methods to DataManager for checking if required metrics exist and for determining if recommendations should be fetched, based on a hash of current metrics and enabled options. This helps avoid redundant recommendation fetches.
• When saving recommendations, now includes the metrics hash in the cached data for accurate comparison on future settings changes. (Fb9cb8f5L261R345)

Testing: Unit, Fixture, and Integration Coverage

• Added fixture and unit tests for has_required_metrics in DataManager, covering all edge cases of metric presence. [1] [2]
• Added fixture, unit, and integration tests for the new subscriber’s logic, ensuring recommendations are only fetched when appropriate and that the event subscription is correct. [1] [2] [3]

Mandatory Checklist

Code validation

• I validated all the Acceptance Criteria. If possible, provide screenshots or videos.
• I triggered all changed lines of code at least once without new errors/warnings/notices.
• I implemented built-in tests to cover the new/changed code.

Code style

• I wrote a self-explanatory code about what it does.
• I protected entry points against unexpected inputs.
• I did not introduce unnecessary complexity.
• Output messages (errors, notices, logs) are explicit enough for users to understand the issue and are actionnable.

[Copilot]

Pull request overview

Adds an automatic “refresh recommendations on relevant WP Rocket settings changes” mechanism for Rocket Insights, using a metrics/options hash to avoid unnecessary API fetches, and introduces new unit/integration test coverage for the decision logic.

Changes:

• Introduces a new Rocket Insights Recommendations SettingsSubscriber intended to react to settings saves and conditionally trigger a recommendations fetch.
• Extends Recommendations\DataManager with required-metrics validation plus hash-based “should fetch” logic, and persists metrics_hash into the cached recommendations payload.
• Adds unit + integration tests and fixtures covering settings-change detection and required-metrics checks.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
inc/Plugin.php	Registers the new recommendations settings subscriber in the common subscriber list.
inc/Engine/Admin/RocketInsights/ServiceProvider.php	Registers the new subscriber service in the Rocket Insights service provider.
inc/Engine/Admin/RocketInsights/Recommendations/SettingsSubscriber.php	Implements settings-change detection and conditional fetch trigger.
inc/Engine/Admin/RocketInsights/Recommendations/DataManager.php	Adds required-metrics check, hash computation/compare, and stores metrics_hash in cache.
tests/Unit/.../SettingsSubscriber/MaybeFetchAfterSettingsChangeTest.php	Unit tests for the subscriber’s fetch decision logic.
tests/Unit/.../SettingsSubscriber/GetSubscribedEventsTest.php	Unit test for subscriber hook registration.
tests/Unit/.../DataManager/HasRequiredMetricsTest.php	Unit tests for required-metrics validation.
tests/Integration/.../SettingsSubscriber/MaybeFetchAfterSettingsChangeTest.php	Integration test intended to validate hook-triggered behavior.
tests/Fixtures/.../SettingsSubscriber/MaybeFetchAfterSettingsChangeTest.php	Fixture data for settings-change scenarios.
tests/Fixtures/.../DataManager/HasRequiredMetricsTest.php	Fixture data for required-metrics scenarios.

[codacy-production]

Coverage summary from Codacy

See diff coverage on Codacy

Coverage variation	Diff coverage
✅ +0.00% (target: -0.10%)	✅ 89.66% (target: 50.00%)

Coverage variation details

	Coverable lines	Covered lines	Coverage
Common ancestor commit (89d01c2)	42866	19690	45.93%
Head commit (b5547fe)	42868 (+2)	19693 (+3)	45.94% (+0.00%)

Coverage variation is the difference between the coverage for the head and common ancestor commits of the pull request branch: <coverage of head commit> - <coverage of common ancestor commit>

Diff coverage details

	Coverable lines	Covered lines	Diff coverage
Pull request (#8140)	29	26	89.66%

Diff coverage is the percentage of lines that are covered by tests out of the coverable lines that the pull request added or modified: <covered lines added or modified>/<coverable lines added or modified> * 100%

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