lots more tests and more efficient prime tester

lib/prime.js

@@ -4,7 +4,9 @@ var findPrime = function(num) {
   if (num < 4) {
     return true;
   }
-  for (var i = 2; i < num; i++) {
+  // http://math.stackexchange.com/a/5281
+  var max = Math.ceil(Math.sqrt(num));
+  for (var i = 2; i <= max; i++) {
     if (num % i === 0) {
       return false;
     }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "interview",
-  "version": "0.0.9",
+  "version": "0.0.11",
   "description": "A collection of command line tools for snarky answers to generic interview questions",
   "main": "bin/fizzbuzz",
   "bin": {

test/ans/1-100p.json

@@ -0,0 +1,100 @@
+["Prime",
+"Prime",
+"Fizz Prime",
+"4",
+"Buzz Prime",
+"Fizz",
+"Prime",
+"8",
+"Fizz",
+"Buzz",
+"Prime",
+"Fizz",
+"Prime",
+"14",
+"FizzBuzz",
+"16",
+"Prime",
+"Fizz",
+"Prime",
+"Buzz",
+"Fizz",
+"22",
+"Prime",
+"Fizz",
+"Buzz",
+"26",
+"Fizz",
+"28",
+"Prime",
+"FizzBuzz",
+"Prime",
+"32",
+"Fizz",
+"34",
+"Buzz",
+"Fizz",
+"Prime",
+"38",
+"Fizz",
+"Buzz",
+"Prime",
+"Fizz",
+"Prime",
+"44",
+"FizzBuzz",
+"46",
+"Prime",
+"Fizz",
+"49",
+"Buzz",
+"Fizz",
+"52",
+"Prime",
+"Fizz",
+"Buzz",
+"56",
+"Fizz",
+"58",
+"Prime",
+"FizzBuzz",
+"Prime",
+"62",
+"Fizz",
+"64",
+"Buzz",
+"Fizz",
+"Prime",
+"68",
+"Fizz",
+"Buzz",
+"Prime",
+"Fizz",
+"Prime",
+"74",
+"FizzBuzz",
+"76",
+"77",
+"Fizz",
+"Prime",
+"Buzz",
+"Fizz",
+"82",
+"Prime",
+"Fizz",
+"Buzz",
+"86",
+"Fizz",
+"88",
+"Prime",
+"FizzBuzz",
+"91",
+"92",
+"Fizz",
+"94",
+"Buzz",
+"Fizz",
+"Prime",
+"98",
+"Fizz",
+"Buzz"]

test/fizz.js

@@ -3,10 +3,12 @@
 require('should');
 
 var oneto100 = require('./ans/1-100.json')
+  , oneto100p = require('./ans/1-100p.json')
   , exec = require('child_process').exec;
 
 var standardFizz = require('../lib/standard')
-  , yieldFizz = require('../lib/yield');
+  , yieldFizz = require('../lib/yield')
+  , findPrime = require('../lib/prime');
 
 describe('fizzbuzz', function() {
   var results = []
@@ -21,41 +23,69 @@ describe('fizzbuzz', function() {
 
     describe('standard', function() {
       it('should run through the basic fizzbuzz test', function() {
-        standardFizz(1, 100, addToResults);
+        standardFizz({s: 1, e: 100}, addToResults);
 
         results.length.should.eql(100);
         for (var i = 0; i < 100; i++) {
           results[i].should.eql(oneto100[i]);
         }
       });
       it('works on numbers other than 1-100', function() {
-        standardFizz(1, 10, addToResults);
+        standardFizz({s: 1, e: 10}, addToResults);
 
         results.length.should.eql(10);
         for (var i = 0; i < 10; i++) {
           results[i].should.eql(oneto100[i]);
         }
       });
+      it('can also display primes', function() {
+        standardFizz({s: 1, e: 100, p: true}, addToResults);
+
+        results.length.should.eql(100);
+        for (var i = 0; i < 100; i++) {
+          results[i].should.eql(oneto100p[i]);
+        }
+      });
     });
 
     describe('yield', function() {
       it('should run through the basic fizzbuzz test', function() {
-        yieldFizz(1, 100, addToResults);
+        yieldFizz({s: 1, e: 100}, addToResults);
 
         results.length.should.eql(100);
         for (var i = 0; i < 100; i++) {
           results[i].should.eql(oneto100[i]);
         }
       });
       it('works on numbers other than 1-100', function() {
-        yieldFizz(1, 10, addToResults);
+        yieldFizz({s: 1, e: 10}, addToResults);
 
         results.length.should.eql(10);
         for (var i = 0; i < 10; i++) {
           results[i].should.eql(oneto100[i]);
         }
       });
+      it('can also display primes', function() {
+        standardFizz({s: 1, e: 100, p: true}, addToResults);
+
+        results.length.should.eql(100);
+        for (var i = 0; i < 100; i++) {
+          results[i].should.eql(oneto100p[i]);
+        }
+      });
     });
+
+    describe('prime', function() {
+      it('finds prime numbers', function() {
+        var isPrime = findPrime('17');
+        isPrime.should.be.true;
+      });
+
+      it('rejects non-prime numbers', function() {
+        var isPrime = findPrime('20');
+        isPrime.should.be.false;
+      });
+    })
   });
 
   describe('integration', function() {
@@ -64,7 +94,7 @@ describe('fizzbuzz', function() {
         function (err, stdout, stderr) {
           if (err) { return done(err); }
 
-          var results = stdout.split('\n')
+          var results = stdout.split('\n');
           results.pop();
           results.should.eql(oneto100);
           stderr.should.eql('');
@@ -77,7 +107,7 @@ describe('fizzbuzz', function() {
         function (err, stdout, stderr) {
           if (err) { return done(err); }
 
-          var results = stdout.split('\n')
+          var results = stdout.split('\n');
           results.pop();
           results.should.eql(oneto100.slice(89));
           stderr.should.eql('');
@@ -90,20 +120,33 @@ describe('fizzbuzz', function() {
         function (err, stdout, stderr) {
           if (err) { return done(err); }
 
-          var results = stdout.split('\n')
+          var results = stdout.split('\n');
           results.pop();
           results.should.eql(oneto100.slice(0, 10));
           stderr.should.eql('');
           done();
       });
     });
 
+    it('uses the prime flag', function(done) {
+      exec('./bin/fizzbuzz -p',
+        function (err, stdout, stderr) {
+          if (err) { return done(err); }
+
+          var results = stdout.split('\n');
+          results.pop();
+          results.should.eql(oneto100p.slice(0, 100));
+          stderr.should.eql('');
+          done();
+      });
+    });
+
     it('uses both flags', function(done) {
       exec('./bin/fizzbuzz -s 10 -e 50',
         function (err, stdout, stderr) {
           if (err) { return done(err); }
 
-          var results = stdout.split('\n')
+          var results = stdout.split('\n');
           results.pop();
           results.should.eql(oneto100.slice(9, 50));
           stderr.should.eql('');