Add comments for deserialization and add tests

src/serialization/sb3.js

@@ -18,6 +18,8 @@ const {loadCostume} = require('../import/load-costume.js');
 const {loadSound} = require('../import/load-sound.js');
 const {deserializeCostume, deserializeSound} = require('./deserialize-assets.js');
 
+const hasOwnProperty = Object.prototype.hasOwnProperty;
+
 /**
  * @typedef {object} ImportedProject
  * @property {Array.<Target>} targets - the imported Scratch 3.0 target objects.
@@ -99,7 +101,7 @@ const primitiveOpcodeInfoMap = {
 const serializePrimitiveBlock = function (block) {
     // Returns an array represeting a primitive block or null if not one of
     // the primitive types above
-    if (primitiveOpcodeInfoMap.hasOwnProperty(block.opcode)) {
+    if (hasOwnProperty.call(primitiveOpcodeInfoMap, block.opcode)) {
         const primitiveInfo = primitiveOpcodeInfoMap[block.opcode];
         const primitiveConstant = primitiveInfo[0];
         const fieldName = primitiveInfo[1];
@@ -132,7 +134,7 @@ const serializePrimitiveBlock = function (block) {
 const serializeInputs = function (inputs) {
     const obj = Object.create(null);
     for (const inputName in inputs) {
-        if (!inputs.hasOwnProperty(inputName)) continue;
+        if (!hasOwnProperty.call(inputs, inputName)) continue;
         // if block and shadow refer to the same block, only serialize one
         if (inputs[inputName].block === inputs[inputName].shadow) {
             // has block and shadow, and they are the same
@@ -166,7 +168,7 @@ const serializeInputs = function (inputs) {
 const serializeFields = function (fields) {
     const obj = Object.create(null);
     for (const fieldName in fields) {
-        if (!fields.hasOwnProperty(fieldName)) continue;
+        if (!hasOwnProperty.call(fields, fieldName)) continue;
         obj[fieldName] = [fields[fieldName].value];
         if (fields[fieldName].hasOwnProperty('id')) {
             obj[fieldName].push(fields[fieldName].id);
@@ -688,8 +690,9 @@ const deserializeInputs = function (inputs, parentId, blocks) {
     // because we call prototype functions later in the vm
     const obj = {};
     for (const inputName in inputs) {
-        if (!inputs.hasOwnProperty(inputName)) continue;
+        if (!hasOwnProperty.call(inputs, inputName)) continue;
         const inputDescArr = inputs[inputName];
+        // If this block has already been deserialized (it's not an array) skip it
         if (!Array.isArray(inputDescArr)) continue;
         let block = null;
         let shadow = null;
@@ -722,8 +725,9 @@ const deserializeFields = function (fields) {
     // because we call prototype functions later in the vm
     const obj = {};
     for (const fieldName in fields) {
-        if (!fields.hasOwnProperty(fieldName)) continue;
+        if (!hasOwnProperty.call(fields, fieldName)) continue;
         const fieldDescArr = fields[fieldName];
+        // If this block has already been deserialized (it's not an array) skip it
         if (!Array.isArray(fieldDescArr)) continue;
         obj[fieldName] = {
             name: fieldName,
@@ -745,13 +749,16 @@ const deserializeFields = function (fields) {
 
 /**
  * Covnert serialized INPUT and FIELD primitives back to hydrated block templates.
+ * Should be able to deserialize a format that has already been deserialized.  The only
+ * "east" path to adding new targets/code requires going through deserialize, so it should
+ * work with pre-parsed deserialized blocks.
  *
  * @param {object} blocks Serialized SB3 "blocks" property of a target. Will be mutated.
  * @return {object} input is modified and returned
  */
 const deserializeBlocks = function (blocks) {
     for (const blockId in blocks) {
-        if (!blocks.hasOwnProperty(blockId)) {
+        if (!Object.prototype.hasOwnProperty.call(blocks, blockId)) {
             continue;
         }
         const block = blocks[blockId];

test/unit/serialization_sb3.js

@@ -182,3 +182,42 @@ test('serialize sb3 preserves sprite layer order', t => {
             t.end();
         });
 });
+
+test('serializeBlocks', t => {
+    const vm = new VirtualMachine();
+    vm.loadProject(readFileToBuffer(commentsSB3ProjectPath))
+        .then(() => {
+            const blocks = vm.runtime.targets[1].blocks._blocks;
+            const result = sb3.serializeBlocks(blocks);
+            // @todo Analyze
+            t.type(result[0], 'object');
+            t.ok(Object.keys(result[0]).length < Object.keys(blocks).length, 'less blocks in serialized format');
+            t.ok(Array.isArray(result[1]));
+            t.end();
+        });
+});
+
+test('deserializeBlocks', t => {
+    const vm = new VirtualMachine();
+    vm.loadProject(readFileToBuffer(commentsSB3ProjectPath))
+        .then(() => {
+            const blocks = vm.runtime.targets[1].blocks._blocks;
+            const serialized = sb3.serializeBlocks(blocks)[0];
+            const deserialized = sb3.deserializeBlocks(serialized);
+            t.equal(Object.keys(deserialized).length, Object.keys(blocks).length, 'same number of blocks');
+            t.end();
+        });
+});
+
+test('deserializeBlocks on already deserialized input', t => {
+    const vm = new VirtualMachine();
+    vm.loadProject(readFileToBuffer(commentsSB3ProjectPath))
+        .then(() => {
+            const blocks = vm.runtime.targets[1].blocks._blocks;
+            const serialized = sb3.serializeBlocks(blocks)[0];
+            const deserialized = sb3.deserializeBlocks(serialized);
+            const deserializedAgain = sb3.deserializeBlocks(deserialized);
+            t.deepEqual(deserialized, deserializedAgain, 'no change from second pass of deserialize');
+            t.end();
+        });
+});