ensure blocks are present before processing

.wp-env.json

@@ -1,5 +1,9 @@
 {
-  "plugins": [".", "./tests/cypress/test-plugin"],
+  "plugins": [
+    ".",
+    "./tests/cypress/test-plugin/e2e-test-plugin.php",
+    "./tests/cypress/test-plugin/e2e-test-plugin-optimizer.php"
+  ],
   "env": {
     "tests": {
       "mappings": {

assets/js/admin/admin.js

@@ -246,6 +246,10 @@ import {select, subscribe} from '@wordpress/data';
     subscribe(() => {
         if (editorStore.isSavingPost()) {
             const changes = editorStore.getPostEdits();
+            // maske sure we have blocks to process
+            if (!Array.isArray(changes.blocks) || !changes.blocks.length) {
+                return;
+            }
             for (const changedBlock of changes.blocks) {
                 const blockName = changedBlock?.name ?? '';
                 const innerBlocks = changedBlock?.innerBlocks ?? [];

tests/cypress/e2e/safe-svg.cy.js

@@ -72,4 +72,13 @@ describe('Safe SVG Tests', () => {
 
     cy.get('.media-item .error-div.error').should('exist').contains('has failed to upload');
   });
+
+
+  // Test plugin doesn't break the block editor when no blocks are added
+  it('Plugin should not break the block editor when optimizer enabled', () => {
+    // Activate Test Plugin
+    cy.deactivatePlugin('safe-svg-cypress-test-plugin');
+    cy.activatePlugin('safe-svg-cypress-optimizer-test-plugin');
+    cy.createPost('Hello World');
+  });
 });

tests/cypress/test-plugin/e2e-test-plugin-optimizer.php

@@ -0,0 +1,12 @@
+<?php
+/**
+ * Plugin name: Safe SVG Cypress Optimizer Test plugin
+ * Description: Test plugin for Safe SVG to test the optimizer.
+ *
+ * @package safe-svg
+ */
+
+/**
+ * Optimizer and allowed attributes can't be mutually enabled, hence the secondary testing plugin.
+ */
+add_filter('safe_svg_optimizer_enabled', '__return_true');