WIP for demo

src/dispatch/shared-dispatch.js

@@ -115,6 +115,12 @@ class SharedDispatch {
     _remoteTransferCall (provider, service, method, transfer, ...args) {
         return new Promise((resolve, reject) => {
             const responseId = this._storeCallbacks(resolve, reject);
+
+            /** @TODO: remove this hack! this is just here so we don't try to send `util` to a worker */
+            if ((args.length > 0) && (typeof args[args.length - 1].yield === 'function')) {
+                args.pop();
+            }
+
             if (transfer) {
                 provider.postMessage({service, method, responseId, args}, transfer);
             } else {

src/engine/runtime.js

@@ -294,6 +294,14 @@ class Runtime extends EventEmitter {
         return 'MONITORS_UPDATE';
     }
 
+    /**
+     * Event name for reporting that an extension was added.
+     * @const {string}
+     */
+    static get EXTENSION_WAS_ADDED () {
+        return 'EXTENSION_WAS_ADDED';
+    }
+
     /**
      * How rapidly we try to step threads by default, in ms.
      */
@@ -371,10 +379,12 @@ class Runtime extends EventEmitter {
 
         for (const blockInfo of extensionInfo.blocks) {
             const convertedBlock = this._convertForScratchBlocks(blockInfo, categoryInfo);
-            const opcode = convertedBlock.json.id;
+            const opcode = convertedBlock.json.type;
             categoryInfo.blocks.push(convertedBlock);
             this._primitives[opcode] = convertedBlock.info.func;
         }
+
+        this.emit(Runtime.EXTENSION_WAS_ADDED, categoryInfo.blocks);
     }
 
     /**
@@ -387,10 +397,8 @@ class Runtime extends EventEmitter {
     _convertForScratchBlocks (blockInfo, categoryInfo) {
         const extendedOpcode = `${categoryInfo.id}.${blockInfo.opcode}`;
         const blockJSON = {
-            id: extendedOpcode,
+            type: extendedOpcode,
             inputsInline: true,
-            previousStatement: null, // null = available connection; undefined = hat block
-            nextStatement: null, // null = available connection; undefined = terminal
             category: categoryInfo.name,
             colour: categoryInfo.color1,
             colourSecondary: categoryInfo.color2,
@@ -436,6 +444,10 @@ class Runtime extends EventEmitter {
         switch (blockInfo.blockType) {
         case BlockType.COMMAND:
             blockJSON.outputShape = ScratchBlocks.OUTPUT_SHAPE_SQUARE;
+            blockJSON.previousStatement = null; // null = available connection; undefined = hat
+            if (!blockInfo.isTerminal) {
+                blockJSON.nextStatement = null; // null = available connection; undefined = terminal
+            }
             break;
         case BlockType.REPORTER:
             blockJSON.output = 'String'; // TODO: distinguish number & string here?
@@ -447,7 +459,7 @@ class Runtime extends EventEmitter {
             break;
         case BlockType.HAT:
             blockJSON.outputShape = ScratchBlocks.OUTPUT_SHAPE_SQUARE;
-            delete blockJSON.previousStatement;
+            blockJSON.nextStatement = null; // null = available connection; undefined = terminal
             break;
         case BlockType.CONDITIONAL:
             // Statement inputs get names like 'SUBSTACK', 'SUBSTACK2', 'SUBSTACK3', ...
@@ -458,6 +470,8 @@ class Runtime extends EventEmitter {
                 };
             }
             blockJSON.outputShape = ScratchBlocks.OUTPUT_SHAPE_SQUARE;
+            blockJSON.previousStatement = null; // null = available connection; undefined = hat
+            blockJSON.nextStatement = null; // null = available connection; undefined = terminal
             break;
         }
 

src/extension-support/extension-manager.js

@@ -65,10 +65,6 @@ class ExtensionManager {
         });
     }
 
-    foo () {
-        return this.loadExtensionURL('extensions/example-extension.js');
-    }
-
     /**
      * Load an extension by URL
      * @param {string} extensionURL - the URL for the extension to load
@@ -77,7 +73,7 @@ class ExtensionManager {
     loadExtensionURL (extensionURL) {
         return new Promise((resolve, reject) => {
             // If we `require` this at the global level it breaks non-webpack targets, including tests
-            const ExtensionWorker = require('worker-loader!./extension-worker');
+            const ExtensionWorker = require('worker-loader?name=extension-worker.js!./extension-worker');
 
             this.pendingExtensions.push({extensionURL, resolve, reject});
             dispatch.addWorker(new ExtensionWorker());

src/extensions/example-extension.js

@@ -33,6 +33,28 @@ class ExampleExtension {
             // Required: the list of blocks implemented by this extension,
             // in the order intended for display.
             blocks: [
+                {
+                    opcode: 'example-noop',
+                    blockType: Scratch.BlockType.COMMAND,
+                    blockAllThreads: false,
+                    text: 'do nothing',
+                    func: 'noop'
+                },
+                {
+                    opcode: 'example-conditional',
+                    blockType: Scratch.BlockType.CONDITIONAL,
+                    branchCount: 4,
+                    isTerminal: true,
+                    blockAllThreads: false,
+                    text: 'choose [BRANCH]',
+                    arguments: {
+                        BRANCH: {
+                            type: Scratch.ArgumentType.NUMBER,
+                            defaultValue: 1
+                        }
+                    },
+                    func: 'noop'
+                },
                 {
                     // Required: the machine-readable name of this operation.
                     // This will appear in project JSON. Must not contain a '.' character.
@@ -110,6 +132,18 @@ class ExampleExtension {
                     // ['sprite', 'stage']
                     filter: ['someBlocks.wedo2', 'sprite', 'stage']
                 },
+                {
+                    opcode: 'example-Boolean',
+                    blockType: Scratch.BlockType.BOOLEAN,
+                    text: 'return true',
+                    func: 'returnTrue'
+                },
+                {
+                    opcode: 'example-hat',
+                    blockType: Scratch.BlockType.HAT,
+                    text: 'after forever',
+                    func: 'returnFalse'
+                },
                 {
                     // Another block...
                 }
@@ -179,6 +213,17 @@ class ExampleExtension {
 
         return ['Letter ', args.LETTER_NUM, ' of ', args.TEXT, ' is ', result, '.'].join('');
     }
+
+    noop () {
+    }
+
+    returnTrue () {
+        return true;
+    }
+
+    returnFalse () {
+        return false;
+    }
 }
 
 Scratch.extensions.register(new ExampleExtension());

src/index.js

@@ -1,10 +1,8 @@
 const VirtualMachine = require('./virtual-machine');
 
 const CentralDispatch = require('./dispatch/central-dispatch');
-const ExtensionManager = require('./extension-support/extension-manager');
 
 global.Scratch = global.Scratch || {};
 global.Scratch.dispatch = CentralDispatch;
-global.Scratch.extensions = new ExtensionManager();
 
 module.exports = VirtualMachine;

src/virtual-machine.js

@@ -1,6 +1,7 @@
 const EventEmitter = require('events');
 
 const centralDispatch = require('./dispatch/central-dispatch');
+const ExtensionManager = require('./extension-support/extension-manager');
 const log = require('./util/log');
 const Runtime = require('./engine/runtime');
 const sb2 = require('./serialization/sb2');
@@ -63,6 +64,11 @@ class VirtualMachine extends EventEmitter {
         this.runtime.on(Runtime.MONITORS_UPDATE, monitorList => {
             this.emit(Runtime.MONITORS_UPDATE, monitorList);
         });
+        this.runtime.on(Runtime.EXTENSION_WAS_ADDED, blocksInfo => {
+            this.emit(Runtime.EXTENSION_WAS_ADDED, blocksInfo);
+        });
+
+        this.extensionManager = new ExtensionManager();
 
         this.blockListener = this.blockListener.bind(this);
         this.flyoutBlockListener = this.flyoutBlockListener.bind(this);