Fixed a few TODOs.

Summary:
1) Moved jshint to a third-party directory

2) Moved calculator.js to genfiles.  This is because I've noticed
several commits over the years that have edited calculator.js
directly, only to have that edit overwritten the next time it was
auto-regenerated.  By putting it in genfiles, I hope to indicate to
people that they should change the source .jison file instead.  (I
still check in the genfiles/ file, so folks can use khan-exercises
without needing to install jison.)

While testing, I realized that we don't do a very good job of
installing deps for you, so I added deps-manifests for the three (!)
programming languages we use, and changed the Makefile to use them.

Small cleanups based on review.

Test Plan:
To test the jshint move, I ran:
   env LC_ALL=en_US.UTF-8 .bundle exec ruby build/pack.rb exercises/z_scores_3.html::exercises-packed/z_scores_3.html
without error.

To test the calculator move/change, I ran:
   python -mSimpleHTTPServer
and visited
   http://localhost:8000/exercises/law_of_cosines.html
and clicked '3+4=' and got 7, and clicked 'ln(-5)' and saw the bar
turn red because it's an error.  (It looks like the actual error
message is suppressed these days.)

(same)

Reviewers: eater, alpert

Reviewed By: alpert

Differential Revision: http://phabricator.khanacademy.org/D9356

.gitignore

@@ -1,6 +1,5 @@
 *.pyc
-_hashed-*.js
+.bundle
+node_modules
 exercises-packed
 exercises-packed.zip
-genfiles/**
-build/lxml

Gemfile

@@ -0,0 +1,6 @@
+source 'https://rubygems.org'
+
+gem 'json', '1.8.0'
+gem 'nokogiri', '1.5.10'
+gem 'therubyracer', '0.12.0'
+gem 'uglifier', '2.3.1'

Makefile

@@ -1,15 +1,28 @@
-utils/calculator.js: build/calculator/calculator.jison build/calculator/calculator-tail.js
-	jison -m js build/calculator/calculator.jison -o utils/Calculator.js
-	cat build/calculator/calculator-tail.js >>utils/Calculator.js
-	mv utils/Calculator.js utils/calculator.js
+.FAKE: pack packed lint fix_lint
+
+# This needs 'npm' on your system, to install jison.
+# The output file has to be named 'Calculator' because that's how jison
+# determines the variable name.
+genfiles/calculator.js: build/calculator/calculator.jison build/calculator/calculator-tail.js
+	npm install
+	mkdir -p genfiles
+	node_modules/.bin/jison -m js build/calculator/calculator.jison -o genfiles/Calculator.js
+	cat build/calculator/calculator-tail.js >>genfiles/Calculator.js
+	mv genfiles/Calculator.js genfiles/calculator.js
+
 
 # Pack all files in exercises/ into exercises-packed/, unless the one
 # in exercises-packed is newer.
-pack packed:
-	args=`cd exercises && find * -name '*.html' | while read infile; do outfile="../exercises-packed/$$infile"; echo "$$outfile" | xargs dirname | xargs mkdir -p; [ "$$outfile" -nt "$$infile" ] || echo "exercises/$$infile::exercises-packed/$$infile"; done`; echo "$$args" | tr ' ' '\012'; [ -z "$$args" ] || ruby build/pack.rb $$args
+# This needs 'bundle' on your system, to install needed ruby modules.
+pack packed: deps
+	args=`cd exercises && find * -name '*.html' | while read infile; do outfile="../exercises-packed/$$infile"; echo "$$outfile" | xargs dirname | xargs mkdir -p; [ "$$outfile" -nt "$$infile" ] || echo "exercises/$$infile::exercises-packed/$$infile"; done`; echo "$$args" | tr ' ' '\012'; [ -z "$$args" ] || env LC_ALL=en_US.UTF-8 bundle exec ruby build/pack.rb $$args
+
 
+# These need 'pip' on your system, to install lxml/etc.
 lint:
+	pip install -r requirements.txt
 	python build/lint_i18n_strings.py exercises/*html
 
 fix_lint:
-	python build/lint_i18n_strings.py --fix exercises/*html
+	pip install -r requirements.txt
+	python build/lint_i18n_strings.py --fix exercises/*html

build/calculator/calculator-tail.js

@@ -39,7 +39,7 @@ window.Calculator = (function(parser) {
                 if (ans !== undefined) {
                     return ans;
                 } else {
-                    throw new CalculatorError("Invalid variable ans");
+                    throw new CalculatorError($._("Invalid variable ans"));
                 }
             } else if (tree === "pi") {
                 return Math.PI;
@@ -61,35 +61,35 @@ window.Calculator = (function(parser) {
                     tan: function(a) {
                         var ans = Math.tan(toRad(a));
                         if (isNaN(ans) || Math.abs(ans) > Math.pow(2, 53)) {
-                            throw new CalculatorError("undefined");
+                            throw new CalculatorError($._("undefined"));
                         }
                         return ans;
                     },
                     asin: function(a) {
                         var ans = fromRad(Math.asin(a));
                         if (isNaN(ans)) {
-                            throw new CalculatorError("undefined");
+                            throw new CalculatorError($._("undefined"));
                         }
                         return ans;
                     },
                     acos: function(a) {
                         var ans = fromRad(Math.acos(a));
                         if (isNaN(ans)) {
-                            throw new CalculatorError("undefined");
+                            throw new CalculatorError($._("undefined"));
                         }
                         return ans;
                     },
                     atan: function(a) {
                         var ans = fromRad(Math.atan(a));
                         if (isNaN(ans)) {
-                            throw new CalculatorError("undefined");
+                            throw new CalculatorError($._("undefined"));
                         }
                         return ans;
                     },
                     ln: function(a) {
                         var ans = Math.log(a);
                         if (isNaN(ans) || !isFinite(ans)) {
-                            throw new CalculatorError("undefined");
+                            throw new CalculatorError($._("undefined"));
                         }
                         return ans;
                     }
@@ -105,7 +105,8 @@ window.Calculator = (function(parser) {
                 }
             } else {
                 throw new CalculatorError(
-                    "Invalid type " + Object.prototype.toString.call(tree));
+                    $._("Invalid type %(type)s",
+                        {type: Object.prototype.toString.call(tree)}));
             }
         },
 

build/pack.rb

@@ -125,7 +125,7 @@ def uglify(js, options)
 Dir.chdir(File.join(File.dirname(__FILE__), ".."))
 
 @uglifier = Uglifier.new(:copyright => false)  # Discard all comments
-@jshint = ExecJS.compile(File.read("build/jshint.js"))
+@jshint = ExecJS.compile(File.read("build/third_party/jshint.js"))
 
 def uglifier_insane(output)
   $stderr.puts "-- unexpected uglifier output: " + output.inspect

khan-exercise.js

@@ -260,14 +260,12 @@ var Khan = {
     // TODO(alpert): This doesn't need to be in the Khan object.
     getBaseModules: function() {
         var mods = [];
-        // Base modules required for every problem
-        // MathJax is here because Perseus wants it loaded regardless of if
-        // we load a khan-exercises problem that needs it. Previously it
-        // was a dependency of 'math' so this isn't really any different.
+        // Base modules required for every problem.  These are specified
+        // as filenames (minus the .js extension) relative to util/.
         // subhints is here to support the intervention experiment.
         mods.push(
             "answer-types", "tmpl", "tex", "jquery.adhesion",
-            "calculator", "scratchpad", "subhints");
+            "scratchpad", "subhints");
 
         return mods;
     },
@@ -1804,7 +1802,7 @@ function prepareSite() {
         $(".calculator-decimal").html(separator);
     }
 
-    require(["./utils/calculator.js"], initializeCalculator);
+    require(["./genfiles/calculator.js"], initializeCalculator);
     Khan.initReportIssueLink("#extras .report-issue-link");
 
     $("#answer_area").delegate("input.button, select", "keydown", function(e) {

lint_blacklist.txt

@@ -3,13 +3,8 @@
 local-only/**
 genfiles/**
 third_party/**
+build/third_party/**
 test/**
 
 # Config files that don't (and shouldn't) end in a semicolon
 requirejs.config.js
-
-# Third-party code in build/.  TODO(csilvers): move to third_party/?
-build/jshint.js
-
-# TODO(csilvers): fix these
-utils/calculator.js

package.json

@@ -0,0 +1,26 @@
+{
+    "name": "khan-exercises",
+    "version": "1.0.0",
+    "author": "Khan Academy",
+    "keywords": "education exercises khanacademy khan math exercises",
+    "description": "(Some) exercises for Khan Academy",
+    "licenses": [
+    {
+        "type": "MIT",
+        "url": "http://www.opensource.org/licenses/mit-license.php"
+    },
+    {
+        "type": "CC Attribution/Non-Commercial/Share-Alike",
+        "url": "http://creativecommons.org/licenses/by-nc-sa/3.0/"
+    }
+    ],
+
+    "repository": {
+        "type": "git",
+        "url": "http://github.com/Khan/khan-exercises/"
+    },
+
+    "devDependencies": {
+        "jison" : "0.4.13"
+    }
+}

requirejs.config.js

@@ -5,11 +5,13 @@
 
         // Base modules used by every problem (matches Khan.getBaseModules())
         "utils/answer-types.js",
-        "utils/calculator.js",
         "utils/tex.js",
         "utils/tmpl.js",
         "utils/jquery.adhesion.js",
 
+        // Loaded separately.
+        "genfiles/calculator.js",
+
         // Utils required asynchronously by khan-exercise.js (when files are
         // required without a callback, r.js will include them automatically)
         "utils/scratchpad.js",
@@ -66,7 +68,7 @@
     out: "genfiles/exercise-content-bundle.js",
     shim: {
         // Wrap these with a define() wrapper to defer execution until required
-        "utils/calculator.js": true,
+        "genfiles/calculator.js": true,
         "utils/jquery.adhesion.js": true,
         "third_party/jquery.cursor-position.js": true,
         "third_party/jquery.mobile.vmouse.js": true

test/index.html

@@ -56,7 +56,7 @@
     <script>
     require([
         "../utils/answer-types.js",
-        "../utils/calculator.js",
+        "../genfiles/calculator.js",
         "../utils/expressions.js",
         "../utils/kline.js",
         "../utils/kmatrix.js",