Ignore video sensing monitor and import music tempo monitor unless it is hidden. Load extensions for visible monitors. Add tests for new functionality.

src/serialization/sb2.js

@@ -245,17 +245,42 @@ const globalBroadcastMsgStateGenerator = (function () {
  * @param {ImportedExtensionsInfo} extensions - (in/out) parsed extension information will be stored here.
  */
 const parseMonitorObject = (object, runtime, targets, extensions) => {
-    let target = null;
+    // In scratch 2.0, there are two monitors that now correspond to extension
+    // blocks (tempo and video motion/direction). In the case of the
+    // video motion/direction block, this reporter is not monitorable in Scratch 3.0.
+    // In the case of the tempo block, we should import it and load the music extension
+    // only when the monitor is actually visible.
+
     const opcode = specMap[object.cmd].opcode;
     const extIndex = opcode.indexOf('_');
     const extID = opcode.substring(0, extIndex);
 
-    // All non-core extensions should be added by blocks at this point
-    // We can assume this is an unintended monitor and skip parsing if it belongs to a non-core extension
-    if (CORE_EXTENSIONS.indexOf(extID) === -1) {
-        if (extID !== '') return;
+    if (extID === 'videoSensing') {
+        return;
+    } else if (CORE_EXTENSIONS.indexOf(extID) === -1 && extID !== '' &&
+        !extensions.extensionIDs.has(extID) && !object.visible) {
+        // Don't import this monitor if it refers to a non-core extension that
+        // doesn't exist anywhere else in the project and it isn't visible.
+        // This should only apply to the tempo block at this point since
+        // there are no other sb2 blocks that are now extension monitors.
+        return;
     }
 
+
+    // if (!object.visible) {
+    //     // If the monitor is invisible, check to see if it tries to load a new extension
+    //     // (e.g. one that hasn't already been loaded by an actual block in the project).
+    //     // If so, exit without importing the monitor.
+    //
+    //
+    //     // All non-core extensions should be added by blocks at this point
+    //     // We can assume this is an unintended monitor and skip parsing if it belongs to a non-core extension
+    //     if () {
+    //         if ( && !extensions.has(extID)) return;
+    //     }
+    // }
+
+    let target = null;
     // List blocks don't come in with their target name set.
     // Find the target by searching for a target with matching variable name/type.
     if (!object.hasOwnProperty('target')) {

test/integration/sb2-import-extension-monitors.js

@@ -0,0 +1,107 @@
+const path = require('path');
+const test = require('tap').test;
+const makeTestStorage = require('../fixtures/make-test-storage');
+const {readFileToBuffer, extractProjectJson} = require('../fixtures/readProjectFile');
+const VirtualMachine = require('../../src/index');
+const sb2 = require('../../src/serialization/sb2');
+
+const invisibleVideoMonitorProjectUri = path.resolve(__dirname, '../fixtures/invisible-video-monitor.sb2');
+const invisibleVideoMonitorProject = readFileToBuffer(invisibleVideoMonitorProjectUri);
+
+const visibleVideoMonitorProjectUri = path.resolve(
+    __dirname, '../fixtures/visible-video-monitor-no-other-video-blocks.sb2');
+const visibleVideoMonitorProject = readFileToBuffer(visibleVideoMonitorProjectUri);
+
+const visibleVideoMonitorAndBlocksProjectUri = path.resolve(
+    __dirname, '../fixtures/visible-video-monitor-and-video-blocks.sb2');
+const visibleVideoMonitorAndBlocksProject = extractProjectJson(visibleVideoMonitorAndBlocksProjectUri);
+
+const invisibleTempoMonitorProjectUri = path.resolve(
+    __dirname, '../fixtures/invisible-tempo-monitor-no-other-music-blocks.sb2');
+const invisibleTempoMonitorProject = readFileToBuffer(invisibleTempoMonitorProjectUri);
+
+const visibleTempoMonitorProjectUri = path.resolve(
+    __dirname, '../fixtures/visible-tempo-monitor-no-other-music-blocks.sb2');
+const visibleTempoMonitorProject = readFileToBuffer(visibleTempoMonitorProjectUri);
+
+test('loading sb2 project with invisible video monitor should not load monitor or extension', t => {
+    const vm = new VirtualMachine();
+    vm.attachStorage(makeTestStorage());
+
+    // Start VM, load project, and run
+    vm.start();
+    vm.clear();
+    vm.setCompatibilityMode(false);
+    vm.setTurboMode(false);
+    vm.loadProject(invisibleVideoMonitorProject).then(() => {
+        t.equal(vm.extensionManager.isExtensionLoaded('videoSensing'), false);
+        t.equal(vm.runtime._monitorState.size, 0);
+        t.end();
+    });
+});
+
+test('loading sb2 project with visible video monitor should not load extension', t => {
+    const vm = new VirtualMachine();
+    vm.attachStorage(makeTestStorage());
+
+    // Start VM, load project, and run
+    vm.start();
+    vm.clear();
+    vm.setCompatibilityMode(false);
+    vm.setTurboMode(false);
+    vm.loadProject(visibleVideoMonitorProject).then(() => {
+        t.equal(vm.extensionManager.isExtensionLoaded('videoSensing'), false);
+        t.equal(vm.runtime._monitorState.size, 0);
+        t.end();
+    });
+});
+
+// This test looks a little different than the rest because loading a project with
+// the video sensing block requires a mock renderer and other setup, so instead
+// we are just using deserialize to test what we need instead
+test('sb2 project with video sensing blocks and monitor should load extension but not monitor', t => {
+    const vm = new VirtualMachine();
+
+    sb2.deserialize(visibleVideoMonitorAndBlocksProject, vm.runtime).then(project => {
+        // Extension loads but monitor does not
+        project.extensions.extensionIDs.has('videoSensing');
+        // Non-core extension monitors haven't been added to the runtime
+        t.equal(vm.runtime._monitorState.size, 0);
+        t.end();
+    });
+});
+
+test('sb2 project with invisible music monitor should not load monitor or extension', t => {
+    const vm = new VirtualMachine();
+    vm.attachStorage(makeTestStorage());
+
+    // Start VM, load project, and run
+    vm.start();
+    vm.clear();
+    vm.setCompatibilityMode(false);
+    vm.setTurboMode(false);
+    vm.loadProject(invisibleTempoMonitorProject).then(() => {
+        t.equal(vm.extensionManager.isExtensionLoaded('music'), false);
+        t.equal(vm.runtime._monitorState.size, 0);
+        t.end();
+    });
+});
+
+test('sb2 project with visible music monitor should load monitor and extension', t => {
+    const vm = new VirtualMachine();
+    vm.attachStorage(makeTestStorage());
+
+    // Start VM, load project, and run
+    vm.start();
+    vm.clear();
+    vm.setCompatibilityMode(false);
+    vm.setTurboMode(false);
+    vm.loadProject(visibleTempoMonitorProject).then(() => {
+        t.equal(vm.extensionManager.isExtensionLoaded('music'), true);
+        t.equal(vm.runtime._monitorState.size, 1);
+        t.equal(vm.runtime._monitorState.has('music_getTempo'), true);
+        t.equal(vm.runtime._monitorState.get('music_getTempo').visible, true);
+        t.end();
+        process.nextTick(process.exit); // This is needed because this is the end of the last test in this file!!
+    });
+});

test/unit/serialization_sb2.js

@@ -5,7 +5,6 @@ const extractProjectJson = require('../fixtures/readProjectFile').extractProject
 const RenderedTarget = require('../../src/sprites/rendered-target');
 const Runtime = require('../../src/engine/runtime');
 const sb2 = require('../../src/serialization/sb2');
-const specMap = require('../../src/serialization/sb2_specmap.js');
 
 test('spec', t => {
     t.type(sb2, 'object');
@@ -103,26 +102,3 @@ test('Ordering', t => {
         t.end();
     });
 });
-
-test('Prevent monitors from adding non-core extensions', t => {
-    const rt = new Runtime();
-    // This test project's video motion reporter block was checked, saved, then unchecked and saved
-    const videoSensingMonitor = path.resolve(__dirname, '../fixtures/invisible-video-monitor.sb2');
-    const projectJSON = extractProjectJson(videoSensingMonitor);
-
-    sb2.deserialize(projectJSON, rt).then(project => {
-        for (const child of projectJSON.children) {
-            // Check that monitor's extension hasn't been added to the serialized project's extensions
-            if (child.cmd) {
-                const opcode = specMap[child.cmd].opcode;
-                const extIndex = opcode.indexOf('_');
-                const extID = opcode.substring(0, extIndex);
-                t.notOk(project.extensions.extensionIDs.has(extID));
-            }
-        }
-
-        // Non-core extension monitors haven't been added to the runtime
-        t.equal(rt._monitorState.size, 0);
-        t.end();
-    });
-});