From aa168c3d5c5dce983dc4f3a52a24bd5e1d435868 Mon Sep 17 00:00:00 2001
From: fredericrous <frederic.rousseau.fr@gmail.com>
Date: Sat, 18 Apr 2020 16:30:05 +0100
Subject: [PATCH] Fix App Calculator issues
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- Javascript rounded float issues
- Reset after equals wasn't done properly
- Introduce unit tests 🤗
---
 apps.json                  |   4 +-
 apps/calculator/ChangeLog  |   1 +
 apps/calculator/app.js     | 146 +++++++++++++-------
 apps/calculator/tests.html | 273 +++++++++++++++++++++++++++++++++++++
 4 files changed, 369 insertions(+), 55 deletions(-)
 create mode 100644 apps/calculator/tests.html

diff --git a/apps.json b/apps.json
index 0c97b9e57..9bd4ee6fb 100644
--- a/apps.json
+++ b/apps.json
@@ -1264,8 +1264,8 @@
     "name": "Calculator",
     "shortName":"Calculator",
     "icon": "calculator.png",
-    "version":"0.01",
-    "description": "Basic calculator reminiscent of MacOs's one. Handy for small calculus. Push button1 and 3 to navigate up/down, tap right or left to navigate the sides, push button 2 to select.",
+    "version":"0.02",
+    "description": "Basic calculator reminiscent of MacOs's one. Handy for small calculus.",
     "tags": "app,tool",
     "storage": [
       {"name":"calculator.app.js","url":"app.js"},
diff --git a/apps/calculator/ChangeLog b/apps/calculator/ChangeLog
index 5560f00bc..3b9b23270 100644
--- a/apps/calculator/ChangeLog
+++ b/apps/calculator/ChangeLog
@@ -1 +1,2 @@
 0.01: New App!
+0.02: fix precision rounding issue + no reset when equals pressed
diff --git a/apps/calculator/app.js b/apps/calculator/app.js
index 91dd7c49d..ad26d2d22 100644
--- a/apps/calculator/app.js
+++ b/apps/calculator/app.js
@@ -144,19 +144,57 @@ function drawKey(name, k, selected) {
   g.drawString(k.val || name, k.xy[0] + RIGHT_MARGIN + rMargin, k.xy[1] + BOTTOM_MARGIN + bMargin);
 }
 
+function getIntWithPrecision(x) {
+  var xStr = x.toString();
+  var xRadix = xStr.indexOf('.');
+  var xPrecision = xRadix === -1 ? 0 : xStr.length - xRadix - 1;
+  return {
+    num: Number(xStr.replace('.', '')),
+    p: xPrecision
+  };
+}
+
+function multiply(x, y) {
+  var xNum = getIntWithPrecision(x);
+  var yNum = getIntWithPrecision(y);
+  return xNum.num * yNum.num / Math.pow(10, xNum.p + yNum.p);
+}
+
+function divide(x, y) {
+  var xNum = getIntWithPrecision(x);
+  var yNum = getIntWithPrecision(y);
+  return xNum.num / yNum.num / Math.pow(10, xNum.p - yNum.p);
+}
+
+function sum(x, y) {
+  let xNum = getIntWithPrecision(x);
+  let yNum = getIntWithPrecision(y);
+
+  let diffPrecision = Math.abs(xNum.p - yNum.p);
+  if (diffPrecision > 0) {
+    if (xNum.p > yNum.p) {
+      yNum.num = yNum.num * Math.pow(10, diffPrecision);
+    } else {
+      xNum.num = xNum.num * Math.pow(10, diffPrecision);
+    }
+  }
+  return (xNum.num + yNum.num) / Math.pow(10, Math.max(xNum.p, yNum.p));
+}
+
+function subtract(x, y) {
+  return sum(x, -y);
+}
+
 function doMath(x, y, operator) {
-  // might not be a number due to display of dot "." algo
-  x = Number(x);
-  y = Number(y);
   switch (operator) {
     case '/':
-      return x / y;
+      return divide(x, y);
     case '*':
-      return x * y;
+      return multiply(x, y);
     case '+':
-      return x + y;
+      return sum(x, y);
     case '-':
-      return x - y;
+      return subtract(x, y);
   }
 }
 
@@ -204,7 +242,7 @@ function displayOutput(num) {
     }
 
     len = (num + '').length;
-    if (numNumeric < 0) {
+    if (numNumeric < 0 || (numNumeric === 0 && 1/numNumeric === -Infinity)) {
       // minus is not available in font 7x11Numeric7Seg, we use Vector
       g.setFont('Vector', 20);
       g.drawString('-', 220 - (len * 15), 10);
@@ -214,18 +252,33 @@ function displayOutput(num) {
   }
   g.drawString(num, 220 - (len * 15) + minusMarge, 10);
 }
-
+var wasPressedEquals = false;
+var hasPressedNumber = false;
 function calculatorLogic(x) {
-  if (hasPressedEquals) {
-    currNumber = results;
+  if (wasPressedEquals && hasPressedNumber !== false) {
     prevNumber = null;
-    operator = null;
-    results = null;
-    isDecimal = null;
-    displayOutput(currNumber);
-    hasPressedEquals = false;
+    currNumber = hasPressedNumber;
+    wasPressedEquals = false;
+    hasPressedNumber = false;
+    return;
   }
-  if (prevNumber != null && currNumber != null && operator != null) {
+  if (hasPressedEquals) {
+    if (hasPressedNumber) {
+      prevNumber = null;
+      hasPressedNumber = false;
+      operator = null;
+    } else {
+      currNumber = null;
+      prevNumber = results;
+    }
+    hasPressedEquals = false;
+    wasPressedEquals = true;
+  }
+
+  if (currNumber == null && operator != null && '/*-+'.indexOf(x) !== -1) {
+    operator = x;
+    displayOutput(prevNumber);
+  } else if (prevNumber != null && currNumber != null && operator != null) {
     // we execute the calculus only when there was a previous number entered before and an operator
     results = doMath(prevNumber, currNumber, operator);
     operator = x;
@@ -255,8 +308,10 @@ function buttonPress(val) {
         operator = null;
       } else {
         keys.R.val = 'AC';
-        drawKey('R', keys.R);
+        drawKey('R', keys.R, true);
       }
+      wasPressedEquals = false;
+      hasPressedNumber = false;
       displayOutput(0);
       break;
     case '%':
@@ -265,11 +320,12 @@ function buttonPress(val) {
       } else if (currNumber != null) {
         displayOutput(currNumber /= 100);
       }
+      hasPressedNumber = false;
       break;
     case 'N':
       if (results != null) {
         displayOutput(results *= -1);
-      } else if (currNumber != null) {
+      } else {
         displayOutput(currNumber *= -1);
       }
       break;
@@ -278,6 +334,7 @@ function buttonPress(val) {
     case '-':
     case '+':
       calculatorLogic(val);
+      hasPressedNumber = false;
       break;
     case '.':
       keys.R.val = 'C';
@@ -290,18 +347,24 @@ function buttonPress(val) {
         results = doMath(prevNumber, currNumber, operator);
         prevNumber = results;
         displayOutput(results);
-        hasPressedEquals = true;
+        hasPressedEquals = 1;
       }
+      hasPressedNumber = false;
       break;
     default:
       keys.R.val = 'C';
       drawKey('R', keys.R);
+      const is0Negative = (currNumber === 0 && 1/currNumber === -Infinity);
       if (isDecimal) {
-        currNumber = currNumber == null ? 0 + '.' + val : currNumber + '.' + val;
+        currNumber = currNumber == null || hasPressedEquals === 1 ? 0 + '.' + val : currNumber + '.' + val;
         isDecimal = false;
       } else {
-        currNumber = currNumber == null ? val : currNumber + val;
+        currNumber = currNumber == null || hasPressedEquals === 1 ? val : (is0Negative ? '-' + val : currNumber + val);
       }
+      if (hasPressedEquals === 1) {
+        hasPressedEquals = 2;
+      }
+      hasPressedNumber = currNumber;
       displayOutput(currNumber);
       break;
   }
@@ -315,38 +378,15 @@ for (var k in keys) {
 g.setFont('7x11Numeric7Seg', 2.8);
 g.drawString('0', 205, 10);
 
-
-setWatch(function() {
-  drawKey(selected, keys[selected]);
-  // key 0 is 2 keys wide, go up to 1 if it was previously selected
-  if (selected == '0' && prevSelected === '1') {
-    prevSelected = selected;
-    selected = '1';
-  } else {
-    prevSelected = selected;
-    selected = keys[selected].trbl[0];
-  }
-  drawKey(selected, keys[selected], true);
-}, BTN1, {repeat: true, debounce: 100});
-
-setWatch(function() {
+function moveDirection(d) {
   drawKey(selected, keys[selected]);
   prevSelected = selected;
-  selected = keys[selected].trbl[2];
+  selected = (d === 0 && selected == '0' && prevSelected === '1') ? '1' : keys[selected].trbl[d];
   drawKey(selected, keys[selected], true);
-}, BTN3, {repeat: true, debounce: 100});
+}
 
-Bangle.on('touch', function(direction) {
-  drawKey(selected, keys[selected]);
-  prevSelected = selected;
-  if (direction == 1) {
-    selected = keys[selected].trbl[3];
-  } else if (direction == 2) {
-    selected = keys[selected].trbl[1];
-  }
-  drawKey(selected, keys[selected], true);
-});
-
-setWatch(function() {
-  buttonPress(selected);
-}, BTN2, {repeat: true, debounce: 100});
+setWatch(_ => moveDirection(0), BTN1, {repeat: true, debounce: 100});
+setWatch(_ => moveDirection(2), BTN3, {repeat: true, debounce: 100});
+setWatch(_ => moveDirection(3), BTN4, {repeat: true, debounce: 100});
+setWatch(_ => moveDirection(1), BTN5, {repeat: true, debounce: 100});
+setWatch(_ => buttonPress(selected), BTN2, {repeat: true, debounce: 100});
diff --git a/apps/calculator/tests.html b/apps/calculator/tests.html
new file mode 100644
index 000000000..1cbfdf617
--- /dev/null
+++ b/apps/calculator/tests.html
@@ -0,0 +1,273 @@
+<!doctype html>
+
+<html lang="en">
+<head>
+  <meta charset="utf-8">
+  <title>Calculator tests</title>
+  <link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/mocha/7.1.0/mocha.min.css">
+  <style>
+    #header {
+      margin: 60px 50px;
+      font: 1em "Helvetica Neue",Helvetica,Arial,sans-serif;
+      font-weight: 200;
+    }
+  </style>
+</head>
+
+<body>
+  <div id="header"></div>
+  <div id="mocha"></div>
+  <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/mocha/7.1.0/mocha.min.js"></script>
+  <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/chai/4.2.0/chai.min.js"></script>
+  <script>
+// mocks
+const _ = () => {}
+setWatch = _
+drawKey = _
+currentOutput = 0;
+g = {
+  setFont: _,
+  drawString: n => currentOutput = n,
+  setColor: _,
+  fillRect: _,
+  clear: _
+}
+_graphics = function () {
+  this.setFontCustom = _
+}
+Graphics = _graphics
+BTN1 = 1
+BTN2 = 2
+BTN3 = 3
+BTN4 = 4
+BTN5 = 5
+Bangle = {
+  on: _
+}
+Terminal = { println: console.log }
+</script>
+<script src="app.js"></script>
+<script>
+header`
+// Unit tests for the BangleJS's Calculator app
+`
+
+mocha.setup({ui:'bdd'})
+chai.should()
+var expect = chai.expect
+
+const sequencePress = x => x.split('').forEach(y => buttonPress(y))
+const sequenceReset = _ => [...Array(2)].forEach(x => buttonPress('R'))
+
+describe("Simple arithmetic", function(){
+  it("multiplication", function(){
+    multiply(1.4,2.4).should.equal(3.36)
+  })
+
+  it("division", function(){
+    divide(4.4,2).should.equal(2.2)
+  })
+
+  it("sum", function(){
+    sum(4.1,2).should.equal(6.1)
+  })
+
+  it("subtract", function(){
+    subtract(4.1,2).should.equal(2.1)
+  })
+})
+
+describe("Simple Operation with Reset", function(){
+  
+  it("Simple addition", function(){
+    sequencePress("50+3=")
+    currentOutput.should.equal(53)
+  })
+
+  it("Reset output 'C' then 'AC'", function(){
+    sequenceReset()
+    currentOutput.should.equal(0)
+  })
+
+  it("Complex calculus", function(){
+    sequenceReset()
+    sequencePress("3*3+3-2/2=")
+    currentOutput.should.equal(5)
+  })
+
+  it("Change operator", function(){
+    sequenceReset()
+    sequencePress("3*+/3=")
+    currentOutput.should.equal(1)
+  })
+})
+
+describe("Operations on Double-s", function(){
+  
+  it("Simple addition", function(){
+    sequenceReset()
+    sequencePress("1.3+1.7=")
+    currentOutput.should.equal(3)
+  })
+
+  it("some calculation", function(){
+    sequenceReset()
+    sequencePress("1.3+1.7*2.22/2=")
+    currentOutput.should.equal(3.33)
+  })
+
+  it("No corrupt opposed to what javascript Number would", function(){
+    sequenceReset()
+    sequencePress("1.3+1.7*2.2/2=")
+    currentOutput.should.equal(3.3)
+  })
+
+  it("Complex calcul", function(){
+    sequenceReset()
+    sequencePress("48/.2/")
+    currentOutput.should.equal(240)
+  })
+})
+
+describe("Negative Operations", function(){
+  
+  it("Negative on first number", function(){
+    sequenceReset()
+    sequencePress("50N+3=")
+    currentOutput.should.equal(-47)
+  })
+
+  it("Substract negative", function(){
+    sequenceReset()
+    sequencePress("50N-3=")
+    currentOutput.should.equal(-53)
+  })
+
+  it("Negative before number is typed", function(){
+    sequenceReset()
+    sequencePress("N50-3=")
+    currentOutput.should.equal(-53)
+  })
+
+  it("Negative addition on second number", function(){
+    sequenceReset()
+    sequencePress("50-N33=")
+    currentOutput.should.equal(83)
+  })
+
+  it("Negative zero", function(){
+    sequenceReset()
+    sequencePress("N")
+    currentOutput.should.equal(-0)
+    sequenceReset()
+    sequencePress("0N")
+    currentOutput.should.equal(-0)
+    sequenceReset()
+    sequencePress("N0")
+    currentOutput.should.equal('-0')
+    sequenceReset()
+    sequencePress("0N")
+    currentOutput.should.equal(-0)
+    sequencePress("N0")
+    currentOutput.should.equal('0')
+  })
+
+})
+
+
+describe("Zero division", function(){
+  
+  it("Divide 0 by 0", function(){
+    sequenceReset()
+    sequencePress("0/0=")
+    currentOutput.should.equal('NOT A NUMBER')
+  })
+
+  it("Divde N by 0", function(){
+    sequenceReset()
+    sequencePress("1/0=")
+    currentOutput.should.equal('INFINITY')
+  })
+
+  it("Divde -N by 0", function(){
+    sequenceReset()
+    sequencePress("N1/0=")
+    currentOutput.should.equal('-INFINITY')
+  })
+})
+
+describe("Press equals '='", function(){
+
+  it("should display result when new operation button is pressed", function(){
+    sequenceReset()
+    sequencePress("5+6+")
+    currentOutput.should.equal(11)
+    sequenceReset()
+    sequencePress("5-6*4/2/")
+    currentOutput.should.equal(-2)
+  })
+
+  it("New operation after '='", function(){
+    sequenceReset()
+    sequencePress("5+4=5")
+    currentOutput.should.equal('5')
+    sequenceReset()
+    sequencePress("N5+4*3-3/-1=5")
+    currentOutput.should.equal('5')
+  })
+
+  it("Double '=' repeats last operation", function(){
+    sequenceReset()
+    sequencePress("2+2==")
+    currentOutput.should.equal(6)
+  })
+
+  it("New operation applied to calculated result", function(){
+    sequenceReset()
+    sequencePress("9*9=*9=")
+    currentOutput.should.equal(729)
+  })
+
+  it("Turn result negative, do addition", function(){
+    sequenceReset()
+    sequencePress("9*9=N+1=")
+    currentOutput.should.equal(-80)
+  })
+
+  it("New operation after '=' dissociated from previous one", function(){
+    sequenceReset()
+    sequencePress("9*9=9*")
+    currentOutput.should.equal('9')
+    sequenceReset()
+    sequencePress("9*9=99+1=*2=")
+    currentOutput.should.equal(200)
+  })
+})
+
+describe("Memory", function(){
+  
+  it("Reset 1st number with 'C'", function(){
+    sequenceReset()
+    sequencePress("50R3+6=")
+    currentOutput.should.equal(9)
+  })
+
+  it("Reset 2nd number with 'C'", function(){
+    sequenceReset()
+    sequencePress("50+3R+6=")
+    currentOutput.should.equal(56)
+  })
+
+  it("Complex calcul", function(){
+    sequenceReset()
+    sequencePress("/3*3+3R-+2/2=")
+    currentOutput.should.equal(5.5)
+  })
+
+})
+
+mocha.run()
+function header(str) { document.getElementById('header').innerHTML = str[0].replace(/\n/, '').replace(/\n/g, '<br>') }
+  </script>
+</body>
+</html>