[React 18] Add full <StrictMode> support (#7007)

src/components/context_menu/context_menu_panel.spec.tsx

@@ -79,6 +79,7 @@ describe('EuiContextMenuPanel', () => {
             ]}
           />
         );
+        cy.get('.euiContextMenuPanel').should('be.focused');
         cy.realPress('{downarrow}');
         cy.focused().should('have.attr', 'data-test-subj', 'itemA');
       });
@@ -100,6 +101,7 @@ describe('EuiContextMenuPanel', () => {
           );
         };
         cy.mount(<DynanicItemsTest />);
+        cy.get('.euiContextMenuPanel').should('be.focused');
         cy.realPress('{downarrow}');
         cy.focused().should('have.attr', 'data-test-subj', 'itemA');
         cy.realPress('{downarrow}');
@@ -144,6 +146,7 @@ describe('EuiContextMenuPanel', () => {
 
       it('focuses the back button panel title by default when no initialFocusedItemIndex is passed', () => {
         cy.mount(<EuiContextMenu panels={panels} initialPanelId="A" />);
+        cy.get('.euiContextMenuPanel').should('be.focused');
         cy.realPress('{downarrow}');
         cy.realPress('{downarrow}');
         cy.focused().should('have.attr', 'data-test-subj', 'panelA');
@@ -155,6 +158,7 @@ describe('EuiContextMenuPanel', () => {
 
       it('focuses the correct toggling item when using the left arrow key to navigate to the previous panel', () => {
         cy.mount(<EuiContextMenu panels={panels} initialPanelId="B" />);
+        cy.get('[data-test-subj="panelB"]').should('be.focused');
         cy.realPress('{leftarrow}');
         cy.focused().should('have.attr', 'data-test-subj', 'panelA');
       });

src/components/datagrid/body/data_grid_cell_popover.spec.tsx

@@ -61,9 +61,10 @@ describe('EuiDataGridCellPopover', () => {
       );
 
       cy.realPress('Escape');
-      cy.focused()
-        .should('have.attr', 'data-gridcell-column-index', '0')
-        .should('have.attr', 'data-gridcell-row-index', '0');
+
+      cy.get(
+        '[data-gridcell-column-index="0"][data-gridcell-row-index="0"]'
+      ).should('be.focused');
     });
 
     it('when the expand button is clicked and then F2 key is pressed', () => {

src/components/flyout/flyout.spec.tsx

@@ -53,15 +53,11 @@ describe('EuiFlyout', () => {
 
     it('traps focus and cycles tabbable items', () => {
       cy.mount(<Flyout />);
-      cy.wait(100); // wait for focus lib to focus the right element
+      cy.get('[data-test-subj="flyoutSpec"]').should('be.focused');
       cy.repeatRealPress('Tab', 4);
-      cy.focused().should('have.attr', 'data-test-subj', 'itemC');
+      cy.get('[data-test-subj="itemC"]').should('be.focused');
       cy.repeatRealPress('Tab', 3);
-      cy.focused().should(
-        'have.attr',
-        'data-test-subj',
-        'euiFlyoutCloseButton'
-      );
+      cy.get('[data-test-subj="euiFlyoutCloseButton"]').should('be.focused');
     });
 
     it('does not focus trap or scrollLock for push flyouts', () => {
@@ -130,7 +126,10 @@ describe('EuiFlyout', () => {
 
     it('closes the flyout when the overlay mask is clicked', () => {
       cy.mount(<Flyout />);
-      cy.get('.euiOverlayMask').should('be.visible').realClick();
+      cy.get('[data-test-subj="flyoutSpec"]').should('be.visible');
+      cy.get('.euiOverlayMask')
+        .should('be.visible')
+        .realClick({ position: 'left' });
       cy.get('[data-test-subj="flyoutSpec"]').should('not.exist');
     });
 

src/components/popover/wrapping_popover.tsx

@@ -22,13 +22,6 @@ export interface EuiWrappingPopoverProps
  */
 export class EuiWrappingPopover extends Component<EuiWrappingPopoverProps> {
   private portal: HTMLElement | null = null;
-  private anchor: HTMLElement | null = null;
-
-  componentDidMount() {
-    if (this.anchor) {
-      this.anchor.insertAdjacentElement('beforebegin', this.props.button);
-    }
-  }
 
   componentWillUnmount() {
     if (this.props.button.parentNode) {
@@ -43,7 +36,7 @@ export class EuiWrappingPopover extends Component<EuiWrappingPopoverProps> {
   };
 
   setAnchorRef = (node: HTMLElement | null) => {
-    this.anchor = node;
+    node?.insertAdjacentElement('beforebegin', this.props.button);
   };
 
   render() {

src/components/portal/portal.tsx

@@ -11,7 +11,7 @@
  * into portals.
  */
 
-import React, { Component, ContextType, ReactNode } from 'react';
+import { Component, ContextType, ReactNode } from 'react';
 import { createPortal } from 'react-dom';
 
 import { EuiNestedThemeContext } from '../../services';
@@ -41,63 +41,79 @@ export interface EuiPortalProps {
   portalRef?: (ref: HTMLDivElement | null) => void;
 }
 
-export class EuiPortal extends Component<EuiPortalProps> {
+interface EuiPortalState {
+  portalNode: HTMLDivElement | null;
+}
+
+export class EuiPortal extends Component<EuiPortalProps, EuiPortalState> {
   static contextType = EuiNestedThemeContext;
   declare context: ContextType<typeof EuiNestedThemeContext>;
 
-  portalNode: HTMLDivElement | null = null;
-
   constructor(props: EuiPortalProps) {
     super(props);
-    if (typeof window === 'undefined') return; // Prevent SSR errors
 
+    this.state = {
+      portalNode: null,
+    };
+  }
+
+  componentDidMount() {
     const { insert } = this.props;
 
-    this.portalNode = document.createElement('div');
-    this.portalNode.dataset.euiportal = 'true';
+    const portalNode = document.createElement('div');
+    portalNode.dataset.euiportal = 'true';
 
     if (insert == null) {
       // no insertion defined, append to body
-      document.body.appendChild(this.portalNode);
+      document.body.appendChild(portalNode);
     } else {
       // inserting before or after an element
       const { sibling, position } = insert;
-      sibling.insertAdjacentElement(insertPositions[position], this.portalNode);
+      sibling.insertAdjacentElement(insertPositions[position], portalNode);
     }
-  }
 
-  componentDidMount() {
-    this.setThemeColor();
-    this.updatePortalRef(this.portalNode);
+    this.setThemeColor(portalNode);
+    this.updatePortalRef(portalNode);
+
+    // Update state with portalNode to intentionally trigger component rerender
+    // and call createPortal with correct root element in render()
+    this.setState({
+      portalNode,
+    });
   }
 
   componentWillUnmount() {
-    if (this.portalNode?.parentNode) {
-      this.portalNode.parentNode.removeChild(this.portalNode);
+    const { portalNode } = this.state;
+    if (portalNode?.parentNode) {
+      portalNode.parentNode.removeChild(portalNode);
     }
     this.updatePortalRef(null);
   }
 
   // Set the inherited color of the portal based on the wrapping EuiThemeProvider
-  setThemeColor() {
-    if (this.portalNode && this.context) {
+  private setThemeColor(portalNode: HTMLDivElement) {
+    if (this.context) {
       const { hasDifferentColorFromGlobalTheme, colorClassName } = this.context;
 
       if (hasDifferentColorFromGlobalTheme && this.props.insert == null) {
-        this.portalNode.classList.add(colorClassName);
+        portalNode.classList.add(colorClassName);
       }
     }
   }
 
-  updatePortalRef(ref: HTMLDivElement | null) {
+  private updatePortalRef(ref: HTMLDivElement | null) {
     if (this.props.portalRef) {
       this.props.portalRef(ref);
     }
   }
 
   render() {
-    return this.portalNode ? (
-      <>{createPortal(this.props.children, this.portalNode)}</>
-    ) : null;
+    const { portalNode } = this.state;
+
+    if (!portalNode) {
+      return null;
+    }
+
+    return createPortal(this.props.children, portalNode);
   }
 }

src/components/tour/tour_step.tsx

@@ -12,7 +12,6 @@ import React, {
   ReactElement,
   ReactNode,
   useEffect,
-  useRef,
   useState,
 } from 'react';
 import classNames from 'classnames';
@@ -164,26 +163,29 @@ export const EuiTourStep: FunctionComponent<EuiTourStepProps> = ({
     );
   }
 
-  const [hasValidAnchor, setHasValidAnchor] = useState<boolean>(false);
-  const animationFrameId = useRef<number>();
-  const anchorNode = useRef<HTMLElement | null>(null);
+  const [anchorNode, setAnchorNode] = useState<HTMLElement | null>(null);
   const [popoverPosition, setPopoverPosition] = useState<EuiPopoverPosition>();
 
   const onPositionChange = (position: EuiPopoverPosition) => {
     setPopoverPosition(position);
   };
 
   useEffect(() => {
+    let timeout: number;
     if (anchor) {
-      animationFrameId.current = window.requestAnimationFrame(() => {
-        anchorNode.current = findElementBySelectorOrRef(anchor);
-        setHasValidAnchor(anchorNode.current ? true : false);
+      // Wait until next tick to find anchor node in case it's not already
+      // in DOM requestAnimationFrame isn't used here because we don't need to
+      // synchronize with repainting ticks and the updated value still
+      // needs to go through a react DOM rerender which may take more than
+      // 1 frame (16ms) of time.
+      // TODO: It would be ideal to have some kind of intersection observer here instead
+      timeout = window.setTimeout(() => {
+        setAnchorNode(findElementBySelectorOrRef(anchor));
       });
     }
 
     return () => {
-      animationFrameId.current &&
-        window.cancelAnimationFrame(animationFrameId.current);
+      timeout && window.clearTimeout(timeout);
     };
   }, [anchor]);
 
@@ -332,8 +334,8 @@ export const EuiTourStep: FunctionComponent<EuiTourStepProps> = ({
     );
   }
 
-  return hasValidAnchor && anchorNode.current ? (
-    <EuiWrappingPopover button={anchorNode.current} {...popoverProps}>
+  return anchorNode ? (
+    <EuiWrappingPopover button={anchorNode} {...popoverProps}>
       {layout}
     </EuiWrappingPopover>
   ) : null;