Merge pull request learn-co-curriculum#1 from learn-co-curriculum/wip-rd

Wip rd

.gitignore

@@ -19,3 +19,4 @@ jspm_packages
 !/log/.keep
 /tmp
 
+.vscode

README.md

@@ -1,16 +1,71 @@
-# Title
+# JavaScript Advanced Functions: Context Lab
 
 ## Learning Goals
 
--SWBAT 1
--SWBAT 2
+* Explicitly override context with `call` and `apply`
 
 ## Introduction
 
-## SWBAT 1
+In this lab, we're going to build the time-card and payroll application using
+the record-oriented approach again. This lab will feature the same topic and
+area of work as the previous lab; _however_, _how_ we call and use functions
+will change with our new knowledge. While the code will stay _mostly_ the same,
+you're going to need to use `this` a lot more.
 
-## SWBAT 2
+The tests guide you to implementing a time card system: when someone enters the
+company's state of the art technical office, the employee has to insert their
+card in a time-clock which will record the time they came in. When it's time to
+leave, the employee will "punch out."
+
+For simplicity's sake, we'll make these assumptions:
+
+1. Assume that employees always check in and check out
+2. Assume employees always check in and our on the hour
+3. The time is represented on a 24-hour clock (1300 is 1:00 pm); this keeps the
+   math easier and is the standard in most of the world
+4. When timestamps are needed, they will be provided as Strings in the form:
+   "YYYY-MM-DD 800" or "YYYY-MM-DD 1800" e.g. "2018-01-01 2300"
+5. Employees will never work across days i.e. in at 2200 and out at 0400 the
+   next day.
+
+The lab tests will guide you toward a solution. Keep in mind, the goal is to
+understand how to "grow" an application in "record-oriented" fashion in
+JavaScript, as well as pass the lab. Make sure you're learning about this app
+design while you pass the solutions.
+
+As before, if you find yourself having extra time, use the guidance in the
+previous lab to make your application more robust.
+
+Take advantage of your collection-processing strengths that you trained up over
+the last few lessons.
+
+Put your code in `index.js`.
+
+## A Mystery on the Horizon
+
+You'll notice that in this lab we give you the implementation of `allWagesFor`.
+As part of writing this challenge, we ran right smack into one of the most
+famous bugs in JavaScript land: "the lost context bug." Because we've not
+taught you to deal with it, we've "given" you this function. We think you can
+solve the other tests with this little piece having been given to you.
+
+If you find yourself having extra time, try researching this topic on your own.
+We'll tell you all about it in our next lesson, though.
 
 ## Conclusion
 
+This is one of the hardest topics in JavaScript. But you have hands-on
+experience with the why and motivations of it! You're so much better off than
+most JavaScript hackers who _never_ quite get the hang of it. It's been a lot
+of growth, but this hard-won knowledge is going to help you do staggeringly
+cool things
+
 ## Resources
+
+* [`bind`][bind]
+* [`call`][call]
+* [`apply`][apply]
+
+[bind]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_objects/Function/bind
+[call]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_objects/Function/call
+[apply]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_objects/Function/apply

index.js

@@ -1,5 +1,22 @@
-const testVar = {}
+/* Your Code Here */
 
-function testFunc() {
-  return "hi"
-}
+/*
+ We're giving you this function. Take a look at it, you might see some usage
+ that's new and different. That's because we're avoiding a well-known, but
+ sneaky bug that we'll cover in the next few lessons!
+
+ As a result, the lessons for this function will pass *and* it will be available
+ for you to use if you need it!
+ */
+
+let allWagesFor = function () {
+    let eligibleDates = this.timeInEvents.map(function (e) {
+        return e.date
+    })
+
+    let payable = eligibleDates.reduce(function (memo, d) {
+        return memo + wagesEarnedOnDate.call(this, d)
+    }.bind(this), 0) // <== Hm, why did we need to add bind() there? We'll discuss soon!
+
+    return payable
+}

package.json

@@ -17,5 +17,8 @@
     "mocha": "5.2.0",
     "mocha-jsdom": "~1.1.0",
     "mocha-multi": "1.0.1"
+  },
+  "dependencies": {
+    "chai-spies": "^1.0.0"
   }
 }

test/helpers.js

@@ -1,9 +1,13 @@
 const chai = require('chai')
 global.expect = chai.expect
+global.chai = chai
 const fs = require('file-system')
 const jsdom = require('mocha-jsdom')
 const path = require('path')
 const babel = require('babel-core');
+const spies = require('chai-spies')
+
+chai.use( spies );
 
 const html = fs.readFileSync(path.resolve(__dirname, '..', 'index.html'), 'utf-8')