Included a function to add sprite 3 to vm

src/virtual-machine.js

@@ -394,6 +394,32 @@ class VirtualMachine extends EventEmitter {
                 this.installTargets(targets, extensions, false));
     }
 
+    /**
+     * Add a single sb3 sprite.
+     * @param {string} json JSON string representing the sprite/target.
+     * @returns {Promise} Promise that resolves after the sprite is added
+     */
+    addSprite3(target) {
+        // Validate & parse
+        if (typeof target !== 'string') {
+            log.error('Failed to parse sprite. Non-string supplied to addSprite3.');
+            return;
+        }
+        target = JSON.parse(target);
+        if (typeof target !== 'object') {
+            log.error('Failed to parse sprite. JSON supplied to addSprite3 is not an object.');
+            return;
+        }
+
+        const jsonFormatted = {
+            targets: [target],
+        };
+
+        return sb3
+            .deserialize(jsonFormatted, this.runtime, null)
+            .then(({ targets, extensions }) => this.installTargets(targets, extensions, false));
+    }
+
     /**
      * Add a costume to the current editing target.
      * @param {string} md5ext - the MD5 and extension of the costume to be loaded.