feat(ui): lazy load modals

ui/src/Components/MainModal/index.js

@@ -6,12 +6,19 @@ import { observable, action } from "mobx";
 
 import { FontAwesomeIcon } from "@fortawesome/react-fontawesome";
 import { faCog } from "@fortawesome/free-solid-svg-icons/faCog";
+import { faSpinner } from "@fortawesome/free-solid-svg-icons/faSpinner";
 
 import { AlertStore } from "Stores/AlertStore";
 import { Settings } from "Stores/Settings";
 import { TooltipWrapper } from "Components/TooltipWrapper";
 import { Modal } from "Components/Modal";
-import { MainModalContent } from "./MainModalContent";
+
+// https://github.com/facebook/react/issues/14603
+const MainModalContent = React.lazy(() =>
+  import("./MainModalContent").then(module => ({
+    default: module.MainModalContent
+  }))
+);
 
 const MainModal = observer(
   class MainModal extends Component {
@@ -49,12 +56,20 @@ const MainModal = observer(
             </TooltipWrapper>
           </li>
           <Modal isOpen={this.toggle.show}>
-            <MainModalContent
-              alertStore={alertStore}
-              settingsStore={settingsStore}
-              onHide={this.toggle.hide}
-              isVisible={this.toggle.show}
-            />
+            <React.Suspense
+              fallback={
+                <h1 className="display-1 text-secondary p-5 m-auto">
+                  <FontAwesomeIcon icon={faSpinner} size="lg" spin />
+                </h1>
+              }
+            >
+              <MainModalContent
+                alertStore={alertStore}
+                settingsStore={settingsStore}
+                onHide={this.toggle.hide}
+                isVisible={this.toggle.show}
+              />
+            </React.Suspense>
           </Modal>
         </React.Fragment>
       );

ui/src/Components/MainModal/index.test.js

@@ -31,12 +31,22 @@ describe("<MainModal />", () => {
     expect(tree.find("MainModalContent")).toHaveLength(0);
   });
 
-  it("renders the modal when it is shown", () => {
+  it("renders a spinner placeholder while modal content is loading", () => {
+    const tree = MountedMainModal();
+    const toggle = tree.find(".nav-link");
+    toggle.simulate("click");
+    expect(tree.find("FontAwesomeIcon")).not.toHaveLength(0);
+    expect(tree.find("MainModalContent")).toHaveLength(0);
+    expect(tree.find(".modal-content").find("svg.fa-spinner")).toHaveLength(1);
+  });
+
+  it("renders modal content if fallback is not used", () => {
     const tree = MountedMainModal();
     const toggle = tree.find(".nav-link");
     toggle.simulate("click");
     expect(tree.find("FontAwesomeIcon")).not.toHaveLength(0);
     expect(tree.find("MainModalContent")).toHaveLength(1);
+    expect(tree.find(".modal-content").find("svg.fa-spinner")).toHaveLength(0);
   });
 
   it("hides the modal when toggle() is called twice", () => {

ui/src/Components/SilenceModal/index.js

@@ -5,16 +5,23 @@ import { observer } from "mobx-react";
 
 import { FontAwesomeIcon } from "@fortawesome/react-fontawesome";
 import { faBellSlash } from "@fortawesome/free-solid-svg-icons/faBellSlash";
+import { faSpinner } from "@fortawesome/free-solid-svg-icons/faSpinner";
 
 import { AlertStore } from "Stores/AlertStore";
 import { SilenceFormStore } from "Stores/SilenceFormStore";
 import { Settings } from "Stores/Settings";
 import { Modal } from "Components/Modal";
 import { TooltipWrapper } from "Components/TooltipWrapper";
-import { SilenceModalContent } from "./SilenceModalContent";
 
 import "./index.css";
 
+// https://github.com/facebook/react/issues/14603
+const SilenceModalContent = React.lazy(() =>
+  import("./SilenceModalContent").then(module => ({
+    default: module.SilenceModalContent
+  }))
+);
+
 const SilenceModal = observer(
   class SilenceModal extends Component {
     static propTypes = {
@@ -42,12 +49,20 @@ const SilenceModal = observer(
             isOpen={silenceFormStore.toggle.visible}
             onExited={silenceFormStore.data.resetProgress}
           >
-            <SilenceModalContent
-              alertStore={alertStore}
-              silenceFormStore={silenceFormStore}
-              settingsStore={settingsStore}
-              onHide={silenceFormStore.toggle.hide}
-            />
+            <React.Suspense
+              fallback={
+                <h1 className="display-1 text-secondary p-5 m-auto">
+                  <FontAwesomeIcon icon={faSpinner} size="lg" spin />
+                </h1>
+              }
+            >
+              <SilenceModalContent
+                alertStore={alertStore}
+                silenceFormStore={silenceFormStore}
+                settingsStore={settingsStore}
+                onHide={silenceFormStore.toggle.hide}
+              />
+            </React.Suspense>
           </Modal>
         </React.Fragment>
       );

ui/src/Components/SilenceModal/index.test.js

@@ -39,12 +39,22 @@ describe("<SilenceModal />", () => {
     expect(tree.find("SilenceModalContent")).toHaveLength(0);
   });
 
-  it("renders the modal when it is shown", () => {
+  it("renders a spinner placeholder while modal content is loading", () => {
+    const tree = MountedSilenceModal();
+    const toggle = tree.find(".nav-link");
+    toggle.simulate("click");
+    expect(tree.find("FontAwesomeIcon")).not.toHaveLength(0);
+    expect(tree.find("SilenceModalContent")).toHaveLength(0);
+    expect(tree.find(".modal-content").find("svg.fa-spinner")).toHaveLength(1);
+  });
+
+  it("renders modal content if fallback is not used", () => {
     const tree = MountedSilenceModal();
     const toggle = tree.find(".nav-link");
     toggle.simulate("click");
     expect(tree.find("FontAwesomeIcon")).not.toHaveLength(0);
     expect(tree.find("SilenceModalContent")).toHaveLength(1);
+    expect(tree.find(".modal-content").find("svg.fa-spinner")).toHaveLength(0);
   });
 
   it("hides the modal when toggle() is called twice", () => {

ui/src/Components/TooltipWrapper/index.js

@@ -1,5 +1,4 @@
 import React from "react";
-import PropTypes from "prop-types";
 
 import { Tooltip } from "react-tippy";
 
@@ -10,14 +9,11 @@ const TooltipWrapper = ({ children, ...props }) => (
     delay={[1000, 100]}
     size="small"
     touchHold={true}
-    style={{ display: "inline-block", "maxWidth": "100%" }}
+    style={{ display: "inline-block", maxWidth: "100%" }}
     {...props}
   >
     {children}
   </Tooltip>
 );
-Tooltip.propTypes = {
-  children: PropTypes.node.isRequired
-};
 
 export { TooltipWrapper };