Allow CandidateBox caret positioning, passing event though onChange. Per https://github.com/hodgef/react-simple-keyboard/issues/1298

src/demo/tests/CandidateBoxDemo.test.js

@@ -0,0 +1,36 @@
+import { setDOM } from '../../utils/TestUtility';
+import CandidateBoxDemo from '../CandidateBoxDemo';
+
+it('Demo will load', () => {
+  setDOM();
+
+  new CandidateBoxDemo();
+});
+
+it('Demo caret positioning will adjust accordingly', () => {
+  setDOM();
+
+  const demo = new CandidateBoxDemo();
+
+  demo.keyboard.setCaretPosition(0);
+
+  demo.keyboard.getButtonElement("n").click();
+  demo.keyboard.getButtonElement("h").click();
+  demo.keyboard.getButtonElement("a").click();
+  demo.keyboard.getButtonElement("o").click();
+  expect(demo.keyboard.getCaretPosition()).toBe(4);
+
+  demo.keyboard.candidateBox.candidateBoxElement.querySelector("li").click();
+
+  expect(demo.keyboard.getCaretPosition()).toBe(2);
+
+  demo.keyboard.setCaretPosition(1);
+  demo.keyboard.getButtonElement("i").click();
+
+  expect(demo.keyboard.getCaretPosition()).toBe(2);
+
+  demo.keyboard.candidateBox.candidateBoxElement.querySelector("li").click();
+
+  expect(demo.keyboard.getCaretPosition()).toBe(1);
+  expect(demo.keyboard.getInput()).toBe("你好");
+});