organize code differently. matuzi style.

lib/growth.js

@@ -0,0 +1,35 @@
+module.exports = function(prev, current, years) { 
+    var yrs = years || 1,
+        growth,
+        doubles = 0,
+        doubleRate = .0,
+        square = prev;
+
+    if (yrs === 1) {
+        growth = ((current-prev)/prev);
+        square = prev * 2;
+        while (prev < square) {
+            doubles++;
+            prev = prev + (prev * growth);
+            if (prev/square > .85) {
+                prev = square;
+            }
+        }
+        return 72/doubles;
+    }
+
+    while (square < current) {
+        doubles++;
+        square = square * 2;
+    }
+
+    if (current/square < .85) {
+        doubles--;
+        if (doubles === 1 && yrs > 1) {
+            yrs--;
+        }
+    }
+
+    doubleRate = yrs/(doubles || 1);
+    return 72/doubleRate;
+};

lib/roic.js

@@ -0,0 +1,4 @@
+// Assumes costs are starting capital
+module.exports = function(capital, sales, costs) { 
+    return Math.floor(100 * (sales - costs)/capital); 
+};

lib/util.js

@@ -1,42 +1,8 @@
+var roic    = require('./roic.js'),
+    growth  = require('./growth.js');
+
 module.exports = {
     // Assumes costs are starting capital
-    roic: function(capital, sales, costs) { 
-        return 100 * (sales - costs)/capital; 
-    },
-
-    growth: function(prev, current, years) {
-        var yrs = years || 1,
-            growth,
-            doubles = 0,
-            doubleRate = .0,
-            square = prev;
-
-        if (yrs === 1) {
-            growth = ((current-prev)/prev);
-            square = prev * 2;
-            while (prev < square) {
-                doubles++;
-                prev = prev + (prev * growth);
-                if (prev/square > .85) {
-                    prev = square;
-                }
-            }
-            return 72/doubles;
-        }
-
-        while (square < current) {
-            doubles++;
-            square = square * 2;
-        }
-
-        if (current/square < .85) {
-            doubles--;
-            if (doubles === 1 && yrs > 1) {
-                yrs--;
-            }
-        }
-
-        doubleRate = yrs/(doubles || 1);
-        return 72/doubleRate;
-    }
+    "roic": roic,
+    "growth": growth
 };

test/lib/growth.js

@@ -0,0 +1,9 @@
+var growth  = require('../../lib/growth.js'),
+    test = require('tap').test;
+/**
+test("Test growth calculation.", function(t) {
+    var result = growth(50, 100, 20);
+    t.equal(result, 160, "roic for da da da");
+    t.end();
+});
+*/

test/lib/roic.js

@@ -0,0 +1,29 @@
+/******************************************************
+** Assumes costs are starting capital
+*******************************************************
+    module.exports = function(capital, sales, costs) { 
+        return 100 * (sales - costs)/capital; 
+    };
+*/
+
+var roic  = require('../../lib/roic.js'),
+    test = require('tap').test;
+
+test("Test roic calculation.", function(t) {
+    var result = roic(50, 100, 20);
+    t.equal(result, 160, "roic for da da da");
+    t.end();
+});
+
+test("Test roic calculation with non-integers mixed in.", function(t) {
+    var result = roic(50.01, 20.02, -.05);
+    var expected = Math.floor(100 * (20.07 / 50.01));
+    t.equal(result, expected, "roic for non integers.");
+    t.end();
+});
+
+test("Test roic calculation.", function(t) {
+    var result = roic('50', '100', '20');
+    t.equal(result, 160, "roic for da da da");
+    t.end();
+});

test/lib/util.js

@@ -1,9 +1,9 @@
 var calculator  = require('../../lib/util.js'),
     test = require('tap').test;
 
-
 test("Test roic calculation.", function(t) {
     var result = calculator.roic(50, 100, 20);
     t.equal(result, 160, "roic for da da da");
     t.end();
 });
+