diff --git a/.DS_Store b/.DS_Store
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diff --git a/README.md b/README.md
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--- a/README.md
+++ /dev/null
@@ -1,53 +0,0 @@
-![CF](https://camo.githubusercontent.com/70edab54bba80edb7493cad3135e9606781cbb6b/687474703a2f2f692e696d6775722e636f6d2f377635415363382e706e67) 01: Node Ecosystem
-===
-
-## Submission Instructions
-* Work in a fork of this repository.
-* Work in a branch on your fork.
-* Write all of your code in a directory named `lab-` + `<your name>` **e.g.** `lab-susan`.
-* Open a pull request to this repository.
-* Submit on canvas a question and observation, how long you spent, and a link to your pull request.
-* Features without unit tests behind them will not be graded.
-
-## Resources  
-* [Jest Getting Started](https://facebook.github.io/jest/docs/en/getting-started.html)
-* [Jest Globals](https://facebook.github.io/jest/docs/en/api.html#content)
-* [Jest Expect](https://facebook.github.io/jest/docs/en/expect.html#content)
-
-## Configuration 
-Configure the root of your repository with the following files and directories. Thoughfully name and organize any aditional configuration or module files.
-* **README.md** - contains documentation
-* **.gitignore** - contains a [robust](http://gitignore.io) `.gitignore` file 
-* **.eslintrc** - contains the course linter configuratoin
-* **.eslintignore** - contains the course linter ignore configuration
-* **lib/** - contains module definitions
-* **__test__/** - contains unit tests
-
-## Feature Tasks
-#### Greet Module
-Create a NodeJS module in the lib/ directory named `greet.js` that exports a single function. 
-* The `greet` function should have a single parameter (arity of one) that should expect a string as it's input
-* The `greet` function should return the input name, concatenated with "hello ": eg. ("hello susan")
-* The `greet` function should return `null` if the input is not a string
-
-#### Arithmetic Module
-Create a NodeJS module in the lib/ directory named `arithmetic.js` that exports an object. This module should have `add` and `sub` methods that implament addition and subtraction.  
-* The `add` method should have an arity of two (define two paramiters)
-  * If either parameter is a non-number the function should return null
-  * Else return the sum of the 2 numbers
-* The `sub` method should have an arity of two (define two paramiters)
-  * If either parameter is a non-number the function should return null
-  * Else return the second paramiter subtracted from the first paramiter
-
-## Testing  
-#### Greet Module Tests
-* Write a test that expects the greet module to return `null` when you supply non string values
-* Write a test the expects the greet module to return `'hello world'`
-  * This should happen when invoked with `'world'` as the first argument
-
-#### Arithmetic Module Tests
-* Test each method for proper use (invoded with number arguments)
-* Test each method for inproper use (invoded with one or more non-numner arguments)
-
-## Documentation  
-In your README.md describe the exported values of each module defined in your lib/ directory. Every function description should include it's airty (expected number of paramiters), the expected data for each paramiter (data-type and limitations), and it's behavior (for both valid and invalued use). Feel free to write any additional information in your README.md.
diff --git a/lab-pedja/.eslintignore b/lab-pedja/.eslintignore
new file mode 100644
index 0000000..05b1cf3
--- /dev/null
+++ b/lab-pedja/.eslintignore
@@ -0,0 +1,5 @@
+**/node_modules/*
+**/vendor/*
+**/*.min.js
+**/coverage/*
+**/build/*
diff --git a/lab-pedja/.eslintrc.json b/lab-pedja/.eslintrc.json
new file mode 100644
index 0000000..840d336
--- /dev/null
+++ b/lab-pedja/.eslintrc.json
@@ -0,0 +1,26 @@
+{
+  "env": {
+    "browser": true,
+    "node": true,
+    "commonjs": true,
+    "jest": true,
+    "es6": true
+  },
+  "globals": {
+    "err": true,
+    "req": true,
+    "res": true,
+    "next": true
+  },
+  "extends": "eslint:recommended",
+  "parserOptions": {
+    "sourceType": "module"
+  },
+  "rules": {
+    "no-console": "off",
+    "indent": [ "error", 2 ],
+    "quotes": ["error", "single", { "allowTemplateLiterals": true }],
+    "comma-dangle": ["error", "always-multiline"],
+    "semi": [ "error", "always" ]
+  }
+}
diff --git a/lab-pedja/.gitignore b/lab-pedja/.gitignore
new file mode 100644
index 0000000..8fe2634
--- /dev/null
+++ b/lab-pedja/.gitignore
@@ -0,0 +1,148 @@
+# Created by https://www.gitignore.io/api/osx,vim,node,linux,windows,visualstudiocode
+
+### Linux ###
+*~
+
+# temporary files which can be created if a process still has a handle open of a deleted file
+.fuse_hidden*
+
+# KDE directory preferences
+.directory
+
+# Linux trash folder which might appear on any partition or disk
+.Trash-*
+
+# .nfs files are created when an open file is removed but is still being accessed
+.nfs*
+
+### Node ###
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+
+# nyc test coverage
+.nyc_output
+
+# 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 (http://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules/
+jspm_packages/
+
+# Typescript v1 declaration files
+typings/
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variables file
+.env
+
+
+### OSX ###
+*.DS_Store
+.AppleDouble
+.LSOverride
+
+# Icon must end with two \r
+Icon
+
+# Thumbnails
+._*
+
+# Files that might appear in the root of a volume
+.DocumentRevisions-V100
+.fseventsd
+.Spotlight-V100
+.TemporaryItems
+.Trashes
+.VolumeIcon.icns
+.com.apple.timemachine.donotpresent
+
+# Directories potentially created on remote AFP share
+.AppleDB
+.AppleDesktop
+Network Trash Folder
+Temporary Items
+.apdisk
+
+### Vim ###
+# swap
+[._]*.s[a-v][a-z]
+[._]*.sw[a-p]
+[._]s[a-v][a-z]
+[._]sw[a-p]
+# session
+Session.vim
+# temporary
+.netrwhist
+# auto-generated tag files
+tags
+
+### VisualStudioCode ###
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+.history
+
+### Windows ###
+# Windows thumbnail cache files
+Thumbs.db
+ehthumbs.db
+ehthumbs_vista.db
+
+# Folder config file
+Desktop.ini
+
+# Recycle Bin used on file shares
+$RECYCLE.BIN/
+
+# Windows Installer files
+*.cab
+*.msi
+*.msm
+*.msp
+
+# Windows shortcuts
+*.lnk
+
+# End of https://www.gitignore.io/api/osx,vim,node,linux,windows,visualstudiocode
diff --git a/lab-pedja/README.md b/lab-pedja/README.md
new file mode 100644
index 0000000..91080d5
--- /dev/null
+++ b/lab-pedja/README.md
@@ -0,0 +1,22 @@
+![CF](https://camo.githubusercontent.com/70edab54bba80edb7493cad3135e9606781cbb6b/687474703a2f2f692e696d6775722e636f6d2f377635415363382e706e67) Lab class 01: Node Ecosystem
+===
+
+#### greet Module
+NodeJS module `greet` located in the lib/ directory(`lib/greet.js`) and it exports a single function - `greet.hi`.
+* The `greet.hi` function has a single parameter (arity of one) that should expect a string as it's input
+* The `greet.hi` function returns the input name, concatenated with "hello ": eg. ("hello world")
+* The `greet.hi` function returns `null` if the input is not a string.
+
+#### arithmetic Module
+NodeJS module `arithmetic` located in the lib/ directory (`lib/arithmetic.js`) and it exports an object. This module has `add` and `sub` methods that implement addition and subtraction.  
+* The `add` method takes two parameters;
+  * If either parameter is a non-number the function returns `null`
+  * Else return the sum of the 2 numbers
+* The `sub` method also takes two parameters;
+  * If either parameter is a non-number the function returns `null`
+  * Else it return the second parameter subtracted from the first parameter.
+
+## Used Resources  
+* [Jest Getting Started](https://facebook.github.io/jest/docs/en/getting-started.html)
+* [Jest Globals](https://facebook.github.io/jest/docs/en/api.html#content)
+* [Jest Expect](https://facebook.github.io/jest/docs/en/expect.html#content)
diff --git a/lab-pedja/__test__/arithmetic.test.js b/lab-pedja/__test__/arithmetic.test.js
new file mode 100644
index 0000000..e9c0a45
--- /dev/null
+++ b/lab-pedja/__test__/arithmetic.test.js
@@ -0,0 +1,33 @@
+'use strict';
+
+const arithmetic = require('../lib/arithmetic');
+
+describe('arithmetic.test.js', () => {
+
+  test('arithmetic.add has 2 number params and returns their sum', () => {
+    expect(arithmetic.add(1,2)).toBe(3);
+  });
+
+  test('arithmetic.add return null is one param is not a number', () => {
+    expect(arithmetic.add(12, '')).toBeNull();
+    expect(arithmetic.add('', 12)).toBeNull();
+    expect(arithmetic.add('hello', 12)).toBeNull();
+    expect(arithmetic.add(12, 'hello')).toBeNull();
+    expect(arithmetic.add('', '')).toBeNull();
+    expect(arithmetic.add('hello', 'world')).toBeNull();
+  });
+
+  test('arithmetic.sub has 2 number params and returns second param subtracted from the first one', () => {
+    expect(arithmetic.sub(2,1)).toBe(1);
+  });
+
+  test('arithmetic.sub return null is one param is not a number', () => {
+    expect(arithmetic.sub(12, '')).toBeNull();
+    expect(arithmetic.sub('', 12)).toBeNull();
+    expect(arithmetic.sub('Pedja', 12)).toBeNull();
+    expect(arithmetic.sub(12, 'Pedja')).toBeNull();
+    expect(arithmetic.sub('', '')).toBeNull();
+    expect(arithmetic.sub('hello', 'world')).toBeNull();
+  });
+
+});
diff --git a/lab-pedja/__test__/greet.test.js b/lab-pedja/__test__/greet.test.js
new file mode 100644
index 0000000..a51d852
--- /dev/null
+++ b/lab-pedja/__test__/greet.test.js
@@ -0,0 +1,17 @@
+'use strict';
+
+const greet = require('../lib/greet');
+
+describe('greet.test.js', () => {
+
+  test('greet.hi has single string param and returns "hello <name>', () => {
+    expect(greet.hi('world')).toEqual('hello world');
+  });
+
+  test('greet.hi returns null if input is not a string', () => {
+    expect(greet.hi('')).toBeNull();
+    expect(greet.hi(1234)).toBeNull();
+    expect(greet.hi(true)).toBeNull();
+  });
+
+});
diff --git a/lab-pedja/lib/arithmetic.js b/lab-pedja/lib/arithmetic.js
new file mode 100644
index 0000000..2bd4856
--- /dev/null
+++ b/lab-pedja/lib/arithmetic.js
@@ -0,0 +1,15 @@
+'use strict';
+
+const arithmetic = module.exports = {};
+
+arithmetic.add = (param1, param2) => {
+  if(typeof param1 !== 'number' || typeof param2 !== 'number')
+    return null;
+  return param1 + param2;
+};
+
+arithmetic.sub = (param1, param2) => {
+  if(typeof param1 !== 'number' || typeof param2 !== 'number')
+    return null;
+  return param1 - param2;
+};
diff --git a/lab-pedja/lib/greet.js b/lab-pedja/lib/greet.js
new file mode 100644
index 0000000..bfc7d31
--- /dev/null
+++ b/lab-pedja/lib/greet.js
@@ -0,0 +1,9 @@
+'use strict';
+
+const greet = module.exports = {};
+
+greet.hi = (name) => {
+  if(name === '' || typeof name !== 'string')
+    return null;
+  return `hello ${name}`;
+};
diff --git a/lab-pedja/package.json b/lab-pedja/package.json
new file mode 100644
index 0000000..bf5e631
--- /dev/null
+++ b/lab-pedja/package.json
@@ -0,0 +1,22 @@
+{
+  "name": "01-node-ecosystem",
+  "version": "1.0.0",
+  "description": "Class01_ecosystem",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/pjosifovic/01-node-ecosystem.git"
+  },
+  "author": "Pedja",
+  "license": "ISC",
+  "bugs": {
+    "url": "https://github.com/pjosifovic/01-node-ecosystem/issues"
+  },
+  "homepage": "https://github.com/pjosifovic/01-node-ecosystem#readme",
+  "devDependencies": {
+    "jest": "^21.2.1"
+  }
+}