Merge branch 'master' of github.com:kolodny/exercises

README.md

@@ -3,14 +3,14 @@ These are some basic (and advanced) coding challenges
 Here's the basic workflow:
 
 ```bash
-git clone https://github.com/kolodny/exercises
-cd exercises
-npm install
-cd throttle
-vi index.js
-npm test
+[~]         $ git clone https://github.com/kolodny/exercises
+[~]         $ cd exercises
+[exercises] $ npm install
+[exercises] $ cd throttle
+[throttle]  $ vi index.js
+[throttle]  $ npm test
 ```
-
+This uses a basic TDD approach so take a look at the test.js file in each directory to see what needs to be implemented, write an index.js as the solution file
 
 ### Contributing
 
@@ -19,3 +19,4 @@ Pull requests welcome, please follow the basic workflow:
 1. Make a folder
 2. Copy a package.json from a sibling folder
 3. Make a test.js file
+4. Optionally provide a README.md

async/README.md

@@ -0,0 +1,37 @@
+Here's the basic usage of the file that you'll be creating:
+
+```js
+var async = require('./') // <- this is the file you make;
+
+var getUser = function(userId) {
+  return function(cb) {
+    setTimeout(function() {
+      cb(null, {userId: userId, name: 'Joe'});
+    }, Math.random() * 100);
+  };
+};
+
+var upperCaseName = function(cb, user) {
+  cb(null, user.name.toUpperCase());
+};
+
+var userThunk = getUser(22);
+
+async.sequence([userThunk, upperCaseName])(function(err, data) {
+  console.log(data); // JOE
+});
+
+var userThunk1 = getUser(1);
+var userThunk2 = getUser(2);
+
+async.parallel([userThunk1, userThunk2])(function(err, users) {
+  console.log(users); // [ { userId: 1, name: 'Joe' }, { userId: 2, name: 'Joe' } ]
+});
+
+var faster = function(cb) {
+  setTimeout(cb.bind(null, null, "I'm faster"), 10);
+}
+async.race([userThunk1, faster])(function(err, winner) {
+  console.log(winner); // I'm faster
+});
+```

curry/README.md

@@ -0,0 +1,14 @@
+Here's the basic usage of the file that you'll be creating:
+
+```js
+var curry = require('./') // <- this is the file you make;
+
+function add(a, b) {
+  return a + b;
+}
+
+var curried = curry(add);
+console.log(  curied(1)(2)  ); // 3
+```
+
+More info: http://en.wikipedia.org/wiki/Curry_%28programming_language%29

memoize/README.md

@@ -0,0 +1,22 @@
+Here's the basic usage of the file that you'll be creating:
+
+```js
+var memoize = require('./') // <- this is the file you make;
+
+function expensiveOperation() {
+  console.log('this should be shown once');
+  return 22;
+}
+
+var memoized = memoize(expensiveOperation);
+console.log(memoized());
+console.log(memoized());
+
+// the console should show:
+// this should be shown once
+// 22
+// 22
+
+```
+
+More info: http://en.wikipedia.org/wiki/Memoization

memoize/package.json

@@ -0,0 +1,6 @@
+{
+  "private": true,
+  "scripts": {
+    "test": "../node_modules/.bin/mocha"
+  }
+}

memoize/test.js

@@ -0,0 +1,31 @@
+var assert = require('assert');
+var memoize = require('./');
+
+describe('memoize', function() {
+
+  it('can handle a single argument', function() {
+    var called = 0;
+    var fib = memoize(function(n) {
+      called++;
+      if (n < 2) return n;
+      return fib(n - 1) + fib(n - 2);
+    });
+    fib(10);
+    assert.equal(called, 11);
+  });
+
+  it('can handle multiple arguments', function() {
+    var called = 0;
+    var fib = memoize(function(n, unused) {
+      called++;
+      if (n < 2) return n;
+      return fib(n - 1, unused) + fib(n - 2, unused);
+    });
+    fib(10, 'x');
+    fib(10, 'y');
+    assert.equal(called, 22);
+
+  });
+
+
+});

middleware/README.md

@@ -0,0 +1,33 @@
+Middleware is the programming pattern of providing hooks with a resume callback.  
+Here's the basic usage of the file that you'll be creating:
+
+```js
+var Middleware = require('./');  // <- this is the file you make;
+
+var middleware = new Middleware();
+
+middleware.use(function(next) {
+  var self = this;
+  setTimeout(function() {
+    self.hook1 = true;
+    next();
+  }, 10);
+});
+
+middleware.use(function(next) {
+  var self = this;
+  setTimeout(function() {
+    self.hook2 = true;
+    next();
+  }, 10);
+});
+
+var start = new Date();
+middleware.go(function() {
+  console.log(this.hook1); // true
+  console.log(this.hook2); // true
+  console.log(new Date() - start); // around 20
+});
+```
+
+More info: http://expressjs.com/guide/using-middleware.html

package.json

@@ -3,7 +3,8 @@
   "private": true,
   "description": "some javascript exercises",
   "scripts": {
-    "test": "mocha '**/test.js'"
+    "test": "echo \"Error: run npm test from inside the challange directories or do `npm run test-all`\" && exit 1",
+    "test-all": "mocha '**/test.js'"
   },
   "author": "Moshe Kolodny",
   "license": "MIT",

throttle/README.md

@@ -0,0 +1,20 @@
+Here's the basic usage of the file that you'll be creating:
+
+```js
+var throttle = require('./') // <- this is the file you make;
+
+var sayHi = function() {
+  console.log('hi');
+};
+
+var throttled = throttle(sayHi, 100);
+
+sayHi();
+sayHi();
+sayHi();
+sayHi();
+
+// there should only be one 'hi' message on the console
+```
+
+More info: http://underscorejs.org/#throttle