Add TDD Style testing to core language stuff

.gitignore

@@ -1,15 +1,6 @@
 # Logs
 logs
 *.log
-npm-debug.log*
-yarn-debug.log*
-yarn-error.log*
-lerna-debug.log*
-**/.DS_Store
-.DS_Store
-
-# Diagnostic reports (https://nodejs.org/api/report.html)
-report.[0-9]*.[0-9]*.[0-9]*.[0-9]*.json
 
 # Runtime data
 pids
@@ -22,48 +13,32 @@ lib-cov
 
 # Coverage directory used by tools like istanbul
 coverage
-*.lcov
 
 # nyc test coverage
 .nyc_output
 
-# Grunt intermediate storage (https://gruntjs.com/creating-plugins#storing-task-files)
+# Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
 .grunt
 
-# Bower dependency directory (https://bower.io/)
-bower_components
-
 # node-waf configuration
 .lock-wscript
 
-# Compiled binary addons (https://nodejs.org/api/addons.html)
+# Compiled binary addons (http://nodejs.org/api/addons.html)
 build/Release
 
 # Dependency directories
 node_modules/
 jspm_packages/
 
-# TypeScript v1 declaration files
+# Typescript v1 declaration files
 typings/
 
-# TypeScript cache
-*.tsbuildinfo
-
 # Optional npm cache directory
 .npm
 
 # Optional eslint cache
 .eslintcache
 
-# Microbundle cache
-.rpt2_cache/
-.rts2_cache_cjs/
-.rts2_cache_es/
-.rts2_cache_umd/
-
-# Optional REPL history
-.node_repl_history
-
 # Output of 'npm pack'
 *.tgz
 
@@ -73,40 +48,24 @@ typings/
 # dotenv environment variables file
 .env
 .env.test
+.env.production
 
-# parcel-bundler cache (https://parceljs.org/)
-.cache
-
-# Next.js build output
-.next
-
-# Nuxt.js build / generate output
-.nuxt
-dist
-
-# Gatsby files
-.cache/
-# Comment in the public line in if your project uses Gatsby and *not* Next.js
-# https://nextjs.org/blog/next-9-1#public-directory-support
-# public
-
-# vuepress build output
-.vuepress/dist
-
-# Serverless directories
-.serverless/
-
-# FuseBox cache
-.fusebox/
+# macOS files
+.DS_Store
+.AppleDouble
+.LSOverride
 
-# DynamoDB Local files
-.dynamodb/
+# Thumbnails
+._*
 
-# TernJS port file
-.tern-port
+# Files that might appear on external disks
+.Spotlight-V100
+.Trashes
 
-# VSCode
-.vscode
+# Windows files
+Thumbs.db
+ehthumbs.db
+Desktop.ini
 
-# IntelliJ
-.idea
+# Visual Studio files
+.vs

conditional.js

@@ -0,0 +1,8 @@
+
+
+const getGreeting = (isMorning) => {
+  return isMorning ? "good Morning": "good Evening";
+}
+
+const result = getGreeting(true);
+console.log(result);

coreLanguageService.js

@@ -0,0 +1,35 @@
+const coreLanguageService = {
+  printHelloWorld: () => {
+    console.log('Hello, world!');
+  },
+  printAllDataTypes: () => {
+    const myNumber = 42;
+    const myString = "Hello, world!";
+    const myBoolean = true;
+    const myUndefined = undefined;
+    const myNull = null;
+    const myObject = { foo: "bar" };
+    const mySymbol = Symbol("mySymbol");
+    const myBigInt = BigInt(9007199254740991);
+    console.log(
+      myNumber,
+      myString,
+      myBoolean,
+      myUndefined,
+      myNull,
+      myObject,
+      mySymbol,
+      myBigInt
+    );
+  },
+  getGreeting: (isMorning) => {
+    return isMorning ? "good Morning": "good Evening";
+  },
+  printLoop: () => {
+    for (let i = 1; i <= 10; i++) {
+      console.log(i);
+    }
+  }
+}
+
+module.exports = coreLanguageService;

index.js

@@ -1,7 +1,8 @@
-
-
+const coreLanguageService = require("./coreLanguageService");
 
 (() => {
-  const result = 'message';
-  console.log(result);
+  coreLanguageService.printHelloWorld();
+  coreLanguageService.printAllDataTypes();
+  console.log(coreLanguageService.getGreeting(true));
+  coreLanguageService.printLoop();
 })();

index.test.js

@@ -0,0 +1,49 @@
+
+const service = require('./coreLanguageService');
+
+describe('devguff-nodejs-language-core', () => {
+  describe("printHelloWorld", () => {
+    it("should print 'Hello, world!' to the console", () => {
+      const consoleLogMock = jest.fn();
+      console.log = consoleLogMock;
+      service.printHelloWorld();
+      expect(consoleLogMock).toHaveBeenCalledWith("Hello, world!");
+    });
+  });
+  describe("printAllDataTypes", () => {
+    it("should use all 8 data types in Node.js", () => {
+      const consoleLogMock = jest.fn();
+      console.log = consoleLogMock;
+      service.printAllDataTypes();
+      expect(consoleLogMock).toHaveBeenCalledWith(
+        42,
+        "Hello, world!",
+        true,
+        undefined,
+        null,
+        { foo: "bar" },
+        expect.any(Symbol),
+        BigInt(9007199254740991)
+      );
+    });
+  });
+  describe("conditional", () => {
+    it("get greeting should return 'good Morning'", () => {
+      expect(service.getGreeting(true)).toBe("good Morning");
+    });
+    it("get greeting should return 'good Evening'", () => {
+      expect(service.getGreeting(false)).toBe("good Evening");
+    });
+  });
+  describe("printLoop", () => {
+    it("should print numbers 1 through 10 to the console", () => {
+      const consoleLogMock = jest.fn();
+      console.log = consoleLogMock;
+      service.printLoop();
+      for (let i = 1; i <= 10; i++) {
+        expect(consoleLogMock).nthCalledWith(i, i);
+      }
+    });
+  });
+})
+