Initial commit of 001code-html Scratch frontend project.

Includes scratch-gui, scratch-vm, scratch-blocks, scratch-render, scratch-l10n, and deployment config.

Co-authored-by: Cursor <cursoragent@cursor.com>

scratch-vm/test/integration/tw_serialize_extensions.js

@@ -0,0 +1,48 @@
+const {test} = require('tap');
+const VirtualMachine = require('../../src/virtual-machine');
+const RenderedTarget = require('../../src/sprites/rendered-target');
+const Sprite = require('../../src/sprites/sprite');
+
+test('Serializes custom extensions', t => {
+    t.plan(6);
+
+    const vm = new VirtualMachine();
+
+    // Trick the extension manager into thinking a couple extensions are loaded.
+    vm.extensionManager.workerURLs[0] = 'https://example.com/test1.js';
+    vm.extensionManager.workerURLs[1] = 'https://example.com/test2.js';
+    // First number in the service names corresponds to index in workerURLs
+    vm.extensionManager._loadedExtensions.set('test1', 'test.0.0');
+    vm.extensionManager._loadedExtensions.set('test2', 'test.1.0');
+
+    const targetUsingBlock = new RenderedTarget(new Sprite(null, vm.runtime), vm.runtime);
+    vm.runtime.addTarget(targetUsingBlock);
+    targetUsingBlock.blocks.createBlock({
+        id: 'a',
+        opcode: 'test1_something'
+    });
+
+    const targetNotUsingBlock = new RenderedTarget(new Sprite(null, vm.runtime), vm.runtime);
+    vm.runtime.addTarget(targetNotUsingBlock);
+
+    // test2 isn't used, so it shouldn't be included in the JSON
+
+    const serializedProject = JSON.parse(vm.toJSON());
+    t.same(serializedProject.extensions, ['test1'], 'save extension IDs for project');
+    t.same(serializedProject.extensionURLs, {
+        test1: 'https://example.com/test1.js'
+    }, 'save extension URLs for project');
+
+    const serializedTargetWithBlock = JSON.parse(vm.toJSON(targetUsingBlock.id));
+    t.same(serializedTargetWithBlock.extensions, ['test1'], 'save extension IDs for sprite');
+    t.same(serializedTargetWithBlock.extensionURLs, {
+        test1: 'https://example.com/test1.js'
+    }, 'save extension URLs for sprite');
+
+    // other sprite uses no extensions, so don't want extension stuff in the JSON
+    const serializedTargetWithoutBlock = JSON.parse(vm.toJSON(targetNotUsingBlock.id));
+    t.notOk('extensions' in serializedTargetWithoutBlock, 'dont save extension IDs for empty sprite');
+    t.notOk('extensionURLs' in serializedTargetWithoutBlock, 'dont save extension URLs for empty sprite');
+
+    t.end();
+});