Add use-detect-outside-click hook

packages/hooks/src/use-detect-outside-click/index.test.tsx

@@ -0,0 +1,75 @@
+/**
+ * Module dependencies.
+ */
+
+import { fireEvent, render, screen } from '@testing-library/react';
+import { useDetectOutsideClick } from './';
+import React, { useRef } from 'react';
+
+/**
+ * `Mock` component.
+ */
+
+const Mock = ({ initiallyActive }: { initiallyActive?: boolean }) => {
+  const ref = useRef<HTMLDivElement>(null);
+  const [active, setActive] = useDetectOutsideClick(ref, initiallyActive);
+
+  return (
+    <>
+      <div
+        onClick={() => setActive(true)}
+        ref={ref}
+      >
+        {active ? 'active' : 'inactive'}
+      </div>
+
+      <div>{'outside'}</div>
+    </>
+  );
+};
+
+/**
+ * Test `useDetectOutsideClick` hook.
+ */
+
+describe(`'useDetectOutsideClick' hook`, () => {
+  it('should lose focus', () => {
+    render(<Mock initiallyActive />);
+
+    expect(screen.queryByText('active')).toBeTruthy();
+
+    fireEvent.click(screen.getByText('outside'));
+
+    expect(screen.queryByText('inactive')).toBeTruthy();
+  });
+
+  it('should gain focus', () => {
+    render(<Mock />);
+
+    expect(screen.queryByText('inactive')).toBeTruthy();
+
+    fireEvent.click(screen.getByText('inactive'));
+
+    expect(screen.queryByText('active')).toBeTruthy();
+  });
+
+  it('should keep focused', () => {
+    render(<Mock initiallyActive />);
+
+    expect(screen.queryByText('active')).toBeTruthy();
+
+    fireEvent.click(screen.getByText('active'));
+
+    expect(screen.queryByText('active')).toBeTruthy();
+  });
+
+  it('should keep unfocused', () => {
+    render(<Mock />);
+
+    expect(screen.queryByText('inactive')).toBeTruthy();
+
+    fireEvent.click(screen.getByText('outside'));
+
+    expect(screen.queryByText('inactive')).toBeTruthy();
+  });
+});

packages/hooks/src/use-detect-outside-click/index.ts

@@ -0,0 +1,48 @@
+/**
+ * Module dependencies.
+ */
+
+import {
+  Dispatch,
+  RefObject,
+  SetStateAction,
+  useEffect,
+  useState
+} from 'react';
+
+/**
+ * `Result` Props.
+ */
+
+type Result = [boolean, Dispatch<SetStateAction<boolean>>];
+
+/**
+ * Export `useDetectOutsideClick` hook.
+ */
+
+export function useDetectOutsideClick(
+  ref: RefObject<HTMLElement> | null | undefined,
+  initialState = false
+): Result {
+  const [active, setActive] = useState(initialState);
+
+  useEffect(() => {
+    const handleClickOutside = ({ target }: MouseEvent) => {
+      if (
+        ref?.current &&
+        target instanceof Element &&
+        !ref?.current?.contains(target)
+      ) {
+        setActive(false);
+      }
+    };
+
+    document.addEventListener('click', handleClickOutside, true);
+
+    return () => {
+      document.removeEventListener('click', handleClickOutside, true);
+    };
+  }, [ref]);
+
+  return [active, setActive];
+}