Add OutOfStockModalComponent

It encapsulate the logic for the out of stock modal

spec/javascripts/stimulus/out_of_stock_modal_controller_test.js

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+/**
+ * @jest-environment jsdom
+ */
+
+import { Application } from "stimulus";
+import out_of_stock_modal_controller from "../../../app/webpacker/controllers/out_of_stock_modal_controller";
+
+describe("OutOfStockModalController", () => {
+  beforeAll(() => {
+    const application = Application.start();
+    application.register("out-of-stock-modal", out_of_stock_modal_controller);
+  });
+
+  let originalWindowLocation = window.location;
+
+  beforeEach(() => {
+    Object.defineProperty(window, "location", {
+      configurable: true,
+      enumerable: true,
+      value: new URL(window.location.href),
+    });
+  });
+
+  afterEach(() => {
+    Object.defineProperty(window, "location", {
+      configurable: true,
+      enumerable: true,
+      value: originalWindowLocation,
+    });
+  });
+
+  // We use window to dispatch the closing event so we don't need to set up another controller
+  describe("#redirect", () => {
+    describe("when redirect value is false", () => {
+      beforeEach(() => {
+        document.body.innerHTML = `
+          <div data-controller="out-of-stock-modal" 
+               data-action="closing@window->out-of-stock-modal#redirect" 
+               data-out-of-stock-modal-redirect-value="false"
+          >
+          </div>
+        `;
+      });
+
+      it("does not redirect", () => {
+        const event = new Event("closing");
+        window.dispatchEvent(event);
+
+        expect(window.location.href).not.toBe("/shop");
+      });
+    });
+
+    describe("when redirect value is true", () => {
+      beforeEach(() => {
+        document.body.innerHTML = `
+          <div data-controller="out-of-stock-modal" 
+               data-action="closing@window->out-of-stock-modal#redirect" 
+               data-out-of-stock-modal-redirect-value="true"
+          >
+          </div>
+        `;
+      });
+
+      it("redirects to /shop", () => {
+        const event = new Event("closing");
+        window.dispatchEvent(event);
+
+        expect(window.location.pathname).toBe("/shop");
+      });
+    });
+  });
+});