Create ChefWorker and move bake process into it

src/core/ChefWorker.js

@@ -0,0 +1,81 @@
+/**
+ * Web Worker to handle communications between the front-end and the core.
+ *
+ * @author n1474335 [n1474335@gmail.com]
+ * @copyright Crown Copyright 2017
+ * @license Apache-2.0
+ */
+
+import "babel-polyfill";
+import Chef from "./Chef.js";
+
+// Set up Chef instance
+self.chef = new Chef();
+
+/**
+ * Respond to message from parent thread.
+ *
+ * Messages should have the following format:
+ * {
+ *     action: "bake" | "silentBake",
+ *     data: {
+ *         input: {string},
+ *         recipeConfig: {[Object]},
+ *         options: {Object},
+ *         progress: {number},
+ *         step: {boolean}
+ *     } | undefined
+ * }
+ */
+self.addEventListener("message", function(e) {
+    // Handle message
+    switch (e.data.action) {
+        case "bake":
+            bake(e.data.data);
+            break;
+        case "silentBake":
+            silentBake(e.data.data);
+            break;
+        default:
+            break;
+    }
+});
+
+
+/**
+ * Baking handler
+ */
+async function bake(data) {
+    try {
+        const response = await self.chef.bake(
+            data.input,          // The user's input
+            data.recipeConfig,   // The configuration of the recipe
+            data.options,        // Options set by the user
+            data.progress,       // The current position in the recipe
+            data.step            // Whether or not to take one step or execute the whole recipe
+        );
+
+        self.postMessage({
+            action: "bakeSuccess",
+            data: response
+        });
+    } catch (err) {
+        self.postMessage({
+            action: "bakeError",
+            data: err
+        });
+    }
+}
+
+
+/**
+ * Silent baking handler
+ */
+function silentBake(data) {
+    const duration = self.chef.silentBake(data.recipeConfig);
+
+    self.postMessage({
+        action: "silentBakeComplete",
+        data: duration
+    });
+}