add module alias '@tests/'

Alias would remove unnecessary repetitions and less relative paths make changes easier when moving around files. This commit cleans also up some relative paths ('../../../') by using the alias and orders imports. It updates both path alias in tsconfig and module alias in Vue CLI's bundler (vuejs/vue-cli#2398).

tests/unit/infrastructure/AsyncLazy.spec.ts

@@ -1,28 +1,24 @@
-import { AsyncLazy } from '@/infrastructure/Threading/AsyncLazy';
 import 'mocha';
 import { expect } from 'chai';
+import { AsyncLazy } from '@/infrastructure/Threading/AsyncLazy';
 
 describe('AsyncLazy', () => {
-
     it('returns value from lambda', async () => {
         // arrange
         const expected = 'test';
         const lambda = () => Promise.resolve(expected);
         const sut = new AsyncLazy(lambda);
-
         // act
         const actual = await sut.getValueAsync();
-
         // assert
         expect(actual).to.equal(expected);
     });
-
     describe('when running multiple times', () => {
+        // arrange
         let totalExecuted: number = 0;
-
         beforeEach(() => totalExecuted = 0);
-
         it('when running sync', async () => {
+            // act
             const sut = new AsyncLazy(() => {
                 totalExecuted++;
                 return Promise.resolve(totalExecuted);
@@ -31,11 +27,12 @@ describe('AsyncLazy', () => {
             for (let i = 0; i < 5; i++) {
                 results.push(await sut.getValueAsync());
             }
+            // assert
             expect(totalExecuted).to.equal(1);
             expect(results).to.deep.equal([1, 1, 1, 1, 1]);
         });
-
         it('when running long-running task in parallel', async () => {
+            // act
             const sleepAsync = (time: number) => new Promise(((resolve) => setTimeout(resolve, time)));
             const sut = new AsyncLazy(async () => {
                 await sleepAsync(100);
@@ -48,6 +45,7 @@ describe('AsyncLazy', () => {
                 sut.getValueAsync(),
                 sut.getValueAsync(),
                 sut.getValueAsync()]);
+            // assert
             expect(totalExecuted).to.equal(1);
             expect(results).to.deep.equal([1, 1, 1, 1, 1]);
         });