macOS: make conversation and main header draggable

ts/test-electron/util/isWindowDragElement_test.ts

@@ -0,0 +1,74 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import { assert } from 'chai';
+
+import { isWindowDragElement } from '../../util/isWindowDragElement';
+
+describe('isWindowDragElement', () => {
+  const crel = (tagName: string, appRegion?: string): Element => {
+    const result = document.createElement(tagName);
+    if (appRegion) {
+      result.style.cssText = `-webkit-app-region: ${appRegion}`;
+    }
+    return result;
+  };
+
+  let sandboxEl: HTMLElement;
+
+  beforeEach(() => {
+    sandboxEl = document.createElement('div');
+    document.body.appendChild(sandboxEl);
+  });
+
+  afterEach(() => {
+    sandboxEl.remove();
+  });
+
+  it('returns false for elements with no -webkit-app-region property in the heirarchy', () => {
+    const root = crel('div');
+    const outer = crel('span');
+    const inner = crel('div');
+    root.appendChild(outer);
+    outer.appendChild(inner);
+    sandboxEl.appendChild(root);
+
+    assert.isFalse(isWindowDragElement(root));
+    assert.isFalse(isWindowDragElement(outer));
+    assert.isFalse(isWindowDragElement(inner));
+  });
+
+  it('returns false for elements with -webkit-app-region: drag on a sub-element', () => {
+    const parent = crel('div');
+    const child = crel('div', 'drag');
+    parent.appendChild(child);
+    sandboxEl.appendChild(parent);
+
+    assert.isFalse(isWindowDragElement(parent));
+  });
+
+  it('returns false if any element up the chain is found to be -webkit-app-region: no-drag', () => {
+    const root = crel('div', 'drag');
+    const outer = crel('div', 'no-drag');
+    const inner = crel('div');
+    root.appendChild(outer);
+    outer.appendChild(inner);
+    sandboxEl.appendChild(root);
+
+    assert.isFalse(isWindowDragElement(outer));
+    assert.isFalse(isWindowDragElement(inner));
+  });
+
+  it('returns true if any element up the chain is found to be -webkit-app-region: drag', () => {
+    const root = crel('div', 'drag');
+    const outer = crel('div');
+    const inner = crel('div');
+    root.appendChild(outer);
+    outer.appendChild(inner);
+    sandboxEl.appendChild(root);
+
+    assert.isTrue(isWindowDragElement(root));
+    assert.isTrue(isWindowDragElement(outer));
+    assert.isTrue(isWindowDragElement(inner));
+  });
+});