[#127] Add UserChip Component

ui/packages/mr-c.app/package.json

@@ -6,6 +6,7 @@
     "dev": "next dev",
     "build": "next build",
     "start": "next start",
+    "test": "jest",
     "lint": "next lint"
   },
   "dependencies": {

ui/packages/mr-c.app/src/components/user-chip.tsx

@@ -0,0 +1,37 @@
+'use client';
+
+import Text from '@/components/atomic/text';
+import { useOutsideClick } from '@/hooks/use-outside-click';
+import { useRef, useState } from 'react';
+
+export default function UserChip({ nickname, tag }: { nickname: string; tag: string }) {
+  const [isDropdownOpen, setDropdownOpen] = useState(false);
+  const ref = useRef<HTMLDivElement>(null);
+
+  const handleClick = () => setDropdownOpen((prev) => !prev);
+  useOutsideClick({ ref, handler: () => setDropdownOpen(false) });
+
+  return (
+    <div ref={ref} className="relative">
+      <div
+        className="flex w-fit items-center rounded bg-gray-100 px-1 hover:bg-gray-200"
+        onClick={handleClick}
+      >
+        <Text weight="medium" nowrap>
+          {nickname}
+        </Text>
+        <Text size="sm" weight="light" nowrap>
+          {tag}
+        </Text>
+      </div>
+      {isDropdownOpen && (
+        // TODO: replace with a normalized Dropdown with a proper event handler
+        <div className="absolute right-0 top-7 flex items-center rounded-lg border bg-white px-2 py-1 opacity-70 hover:bg-gray-200">
+          <Text color="black" size="sm">
+            작성글 보기
+          </Text>
+        </div>
+      )}
+    </div>
+  );
+}

ui/packages/mr-c.app/src/hooks/use-outside-click.test.tsx

@@ -0,0 +1,105 @@
+import { useRef } from 'react';
+import { useOutsideClick } from '@/hooks/use-outside-click';
+import { cleanup, click, clickRight, pointerDown, pointerUp, render } from '@/lib/test-utils';
+
+function OutsideClicker({ onOutsideClick }: { onOutsideClick: () => void }) {
+  const ref = useRef<HTMLDivElement>(null);
+
+  useOutsideClick({
+    ref,
+    handler: onOutsideClick,
+  });
+
+  return (
+    <>
+      <div ref={ref}>Element</div>
+      <div>Outside</div>
+    </>
+  );
+}
+
+describe('useOutsideClick', () => {
+  let outsideClickCount: number;
+  let element: HTMLElement;
+  let outsideElement: HTMLElement;
+
+  beforeEach(() => {
+    outsideClickCount = 0;
+  });
+
+  beforeAll(() => {
+    const { getByText } = render(<OutsideClicker onOutsideClick={() => outsideClickCount++} />);
+
+    element = getByText('Element');
+    outsideElement = getByText('Outside');
+  });
+
+  afterAll(() => {
+    cleanup();
+  });
+
+  test('should register clicks on other elements, the body, and the document', () => {
+    expect(outsideClickCount).toEqual(0);
+
+    click(element);
+    expect(outsideClickCount).toEqual(0);
+
+    click(outsideElement);
+    expect(outsideClickCount).toEqual(1);
+
+    click(document);
+    expect(outsideClickCount).toEqual(2);
+
+    click(document.body);
+    expect(outsideClickCount).toEqual(3);
+  });
+
+  test('should register right clicks on other elements, the body, and the document', () => {
+    expect(outsideClickCount).toEqual(0);
+
+    clickRight(element);
+    expect(outsideClickCount).toEqual(0);
+
+    clickRight(outsideElement);
+    expect(outsideClickCount).toEqual(1);
+
+    clickRight(document);
+    expect(outsideClickCount).toEqual(2);
+
+    clickRight(document.body);
+    expect(outsideClickCount).toEqual(3);
+  });
+
+  test('should fire once on one click sequnce: mouse Down -> Up', () => {
+    expect(outsideClickCount).toEqual(0);
+
+    pointerDown(outsideElement);
+    expect(outsideClickCount).toEqual(0);
+    pointerUp(outsideElement);
+    expect(outsideClickCount).toEqual(1);
+
+    pointerDown(outsideElement);
+    pointerDown(outsideElement);
+    expect(outsideClickCount).toEqual(1);
+
+    pointerUp(outsideElement);
+    pointerUp(outsideElement);
+    expect(outsideClickCount).toEqual(2);
+  });
+
+  test('should fire for the click that both mouse Down/Up happen outside', () => {
+    expect(outsideClickCount).toEqual(0);
+
+    pointerDown(element);
+    pointerUp(outsideElement);
+    expect(outsideClickCount).toEqual(0);
+
+    pointerDown(outsideElement);
+    pointerUp(element);
+    expect(outsideClickCount).toEqual(0);
+
+    pointerDown(outsideElement);
+    pointerUp(outsideElement);
+    expect(outsideClickCount).toEqual(1);
+  });
+});

ui/packages/mr-c.app/src/hooks/use-outside-click.ts

@@ -0,0 +1,42 @@
+import { useEffect, useRef } from 'react';
+
+interface UseOutsideClickProps {
+  ref: React.RefObject<HTMLElement>;
+  handler?: (e: Event) => void;
+}
+
+export function useOutsideClick({ ref, handler }: UseOutsideClickProps) {
+  const stateRef = useRef({
+    isPointerDown: false,
+  });
+
+  const state = stateRef.current;
+
+  useEffect(() => {
+    const onPointerDown = (event: PointerEvent) => {
+      if (isValidEvent(event, ref)) {
+        state.isPointerDown = true;
+      }
+    };
+
+    const onPointerUp = (event: PointerEvent) => {
+      if (state.isPointerDown && handler && isValidEvent(event, ref)) {
+        state.isPointerDown = false;
+        handler(event);
+      }
+    };
+
+    document.addEventListener('pointerdown', onPointerDown, true);
+    document.addEventListener('pointerup', onPointerUp, true);
+
+    return () => {
+      document.removeEventListener('pointerdown', onPointerDown, true);
+      document.removeEventListener('pointerup', onPointerUp, true);
+    };
+  }, [handler, ref, state]);
+}
+
+function isValidEvent(event: Event, ref: React.RefObject<HTMLElement>) {
+  const target = event.target;
+  return target instanceof Node && !ref.current?.contains(target);
+}

ui/packages/mr-c.app/src/lib/test-utils/index.ts

@@ -0,0 +1,19 @@
+import { fireEvent } from '@testing-library/react/pure';
+export { cleanup, render } from '@testing-library/react/pure';
+// why use pure?
+// to avoid cleanup afterEach
+// so we can render once beforeAll
+// https://github.com/testing-library/react-testing-library/issues/541
+
+export function click(el: Node) {
+  fireEvent.pointerDown(el);
+  fireEvent.pointerUp(el);
+}
+
+export function clickRight(el: Node) {
+  fireEvent.pointerDown(el, { button: 2 });
+  fireEvent.pointerUp(el, { button: 2 });
+}
+
+export const pointerDown = (el: Node) => fireEvent.pointerDown(el);
+export const pointerUp = (el: Node) => fireEvent.pointerUp(el);