add readme 和注释

common_ui/src/test/List.test.ets

@@ -0,0 +1,5 @@
+import localUnitTest from './LocalUnit.test';
+
+export default function testsuite() {
+  localUnitTest();
+}

common_ui/src/test/LocalUnit.test.ets

@@ -0,0 +1,33 @@
+import { describe, beforeAll, beforeEach, afterEach, afterAll, it, expect } from '@ohos/hypium';
+
+export default function localUnitTest() {
+  describe('localUnitTest',() => {
+    // Defines a test suite. Two parameters are supported: test suite name and test suite function.
+    beforeAll(() => {
+      // Presets an action, which is performed only once before all test cases of the test suite start.
+      // This API supports only one parameter: preset action function.
+    });
+    beforeEach(() => {
+      // Presets an action, which is performed before each unit test case starts.
+      // The number of execution times is the same as the number of test cases defined by **it**.
+      // This API supports only one parameter: preset action function.
+    });
+    afterEach(() => {
+      // Presets a clear action, which is performed after each unit test case ends.
+      // The number of execution times is the same as the number of test cases defined by **it**.
+      // This API supports only one parameter: clear action function.
+    });
+    afterAll(() => {
+      // Presets a clear action, which is performed after all test cases of the test suite end.
+      // This API supports only one parameter: clear action function.
+    });
+    it('assertContain', 0, () => {
+      // Defines a test case. This API supports three parameters: test case name, filter parameter, and test case function.
+      let a = 'abc';
+      let b = 'b';
+      // Defines a variety of assertion methods, which are used to declare expected boolean conditions.
+      expect(a).assertContain(b);
+      expect(a).assertEqual(a);
+    });
+  });
+}