add unit test coverage to init lifecycle hook feature

src/utils/UserFunction.ts

@@ -112,15 +112,14 @@ function _loadUserApp(
 
 async function _initializeFunction(userApp: any): Promise<void> {
   try {
-     await userApp.initializeFunction();
+    await userApp.initializeFunction();
   } catch (e) {
-      if (e instanceof TypeError) {
-          // initializeFunction lifecycle hook not implemented
-          return;
-      }
-      else {
-          throw e;
-      }
+    if (e instanceof TypeError) {
+      // initializeFunction lifecycle hook not implemented
+      return;
+    } else {
+      throw e;
+    }
   }
 }
 

test/unit/utils/UserFunction.test.ts

@@ -0,0 +1,44 @@
+/** Copyright 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. */
+
+"use strict";
+
+require("should");
+import { load } from "../../../src/utils/UserFunction";
+
+describe("Invoking the load function", async() => {
+    it("should resolve promise when init hook function is present", async() => {
+        const handler = "InitPresent.handler"
+        const appRoot = "test/unit/utils/function";
+
+        const handlerFunc = (await load(
+            appRoot,
+            handler
+        )) as Function;
+
+        handlerFunc.should.be.Function;
+        handlerFunc().should.be.true;
+    });
+    it("should not fail when init hook function is absent", async() => {
+        const handler = "InitAbsent.handler"
+        const appRoot = "test/unit/utils/function";
+
+        const handlerFunc = (await load(
+            appRoot,
+            handler
+        )) as Function;
+
+        handlerFunc.should.be.Function;
+    });
+    it("should catch TypeError exception", async() => {
+        const handler = "InitThrowsTypeError.handler"
+        const appRoot = "test/unit/utils/function";
+
+        const handlerFunc = (await load(
+            appRoot,
+            handler
+        )) as Function;
+
+        handlerFunc.should.be.Function;
+        handlerFunc().should.be.true;
+    });
+});

test/unit/utils/function/InitAbsent.js

@@ -0,0 +1,24 @@
+// console.log("******** enter the init block   ********");
+
+let resolved = false;
+
+function sleep(ms) {
+  return new Promise((resolve) => setTimeout(resolve, ms)).then(() => {resolved = true});
+}
+
+async function init() {
+  // console.log("******** enter initializeFunction hook ********");
+  // console.log("******** Is promised resolved? " + resolved + " ********");
+  // console.log("******** sleep for 20 ms... ********")
+  let p = await sleep(20);
+  // console.log("******** wake up                ********");
+  // console.log("******** Is promised resolved? " + resolved + " ********");
+}
+
+init();
+
+exports.handler = async (event, context) => {
+    // console.log("******** enter the handler        ********");
+    // console.log("******** Is promised resolved? " + resolved + " ********");
+    return ( resolved ? true: false );
+}

test/unit/utils/function/InitPresent.js

@@ -0,0 +1,22 @@
+// console.log("******** enter the init block   ********");
+
+let resolved = false;
+
+function sleep(ms) {
+  return new Promise((resolve) => setTimeout(resolve, ms)).then(() => {resolved = true});
+}
+
+exports.initializeFunction = async () => {
+  // console.log("******** enter initializeFunction hook ********");
+  // console.log("******** Is promised resolved? " + resolved + " ********");
+  // console.log("******** sleep for 20 ms... ********")
+  let p = await sleep(20);
+  // console.log("******** wake up                ********");
+  // console.log("******** Is promised resolved? " + resolved + " ********");
+}
+
+exports.handler = async (event, context) => {
+    // console.log("******** enter the handler        ********");
+    // console.log("******** Is promised resolved? " + resolved + " ********");
+    return ( resolved ? true: false );
+}

test/unit/utils/function/InitThrowsTypeError.js

@@ -0,0 +1,7 @@
+exports.initializeFunction = async () => {
+    throw new TypeError;
+}
+
+exports.handler = async (event, context) => {
+    return true;
+}