string-math - npm Package Compare versions

Comparing version 1.0.0 to 1.2.1

package.json

 {
   "name": "string-math",
-  "version": "1.0.0",
+  "version": "1.2.1",
   "description": "Evaluates the result of the String arithmetical expression",
@@ -5,0 +5,0 @@ "main": "string-math.js",

readme.md

@@ -5,3 +5,3 @@ # Description
 * It **does not use** `eval()`
-* It uses regular expressions to parse [String] equations
+* It uses regular expressions to parse [String] formulas `"2+2"` into [Number] formulas `2+2`. Then it is performed as the common JavaScript arithmetic operation.
 
@@ -13,6 +13,7 @@ ```javascript
 "3.5+5*(-4-(3/(3+1)-12*3-.2*22)-16/4*12-5/(2)+3.5+2.5*(1.5-2*7))-16" //-225.5
+".25e+2*10" //250
 ```
 
 * Any bugs found? Give me to know on [GitHub](https://github.com/devrafalko/string-math)
-* Also check out [**`exact-math`**](https://www.npmjs.com/package/exact-math) to compute arithmetical formulas with precise floating point values; *(get rid of `0.30000000000000004` values)*
+* If you need to perform arithmetic formulas with the **floating point precision** *(avoid `0.30000000000000004` return values)* or to perform arithmetic formulas with **big numbers**, check out [**`exact-math`**](https://www.npmjs.com/package/exact-math) package. It implements `string-math` features as the `exactMath.formula` method.
 
@@ -65,3 +66,3 @@
 
-### `stringMath(expression)`
+### `stringMath(expression[,callback])`
 ##### `expression` **[String]**
@@ -73,2 +74,3 @@ * the arithmetical formula
   * `-5`, `-.4`, `-5.55` negative values
+  * `2e-2`, `.25e+12`, `-3e-10` exponential notation values
   * `*` multiplication sign
@@ -80,2 +82,16 @@ * `/` division sign
 
+##### `callback` **[Function]** *(optional)* *(synchronous)*
+* by default, if the `callback` argument **is omitted** and the `expression` is of incorrect type or is invalid, the `Error` object is **`thrown`**. If the `callback` is defined, the `Error` object is passed through the `callback` function, rather than being **`thrown`**.
+* if the [Function] `callback` argument is defined, it is called with the following arguments:
+  * [0] `error`  
+    It equals `null`, if the `expression` is of correct type and is valid math formula.  
+    Otherwise it equals `Error` object.
+  * [1] `result`  
+    It equals `null` if the `expression` is of incorrect type or if the math formula is invalid.  
+    Otherwise it equals [Number] result.
+
+# Return
+
+If the math formula is of correct type and is valid, it returns the [Number] result. Otherwise it returns `null`.
+
 # Tips
@@ -100,5 +116,7 @@ * the arithmetic **order of operations** is respected:
   * `  -.1   -   -5`
+  * `2 + 3e-5`
+  * `.25e+5 * -.25e-5`
 * the spaces are **not allowed** between:
   * negative sign and value: `-2 - - 2`
   * period and digit in decimal fraction: `5 + . 3`
-  * uneven opening and closing brackets: `5 + (3 * (3 + 4)` 
+  * exponential notation formula: `.2 e-5`, `2e - 5`, `3e +10`

string-math.js

@@ -1,20 +0,20 @@
-function stringMath(eq){
-  if(typeof eq !== 'string') throw TypeError('The [String] argument is expected.');
-  const mulDiv = /(-?\d*\.?\d+)\s*([*/])\s*([+-]?\d*\.?\d+)/;
-  const plusMin = /([+-]?\d*\.?\d+)\s*([+-])\s*([+-]?\d*\.?\d+)/;
+function stringMath(eq, callback) {
+  if (typeof eq !== 'string') return handleCallback(new TypeError('The [String] argument is expected.'), null);
+  const mulDiv = /([+-]?\d*\.?\d+(?:e[+-]\d+)?)\s*([*/])\s*([+-]?\d*\.?\d+(?:e[+-]\d+)?)/;
+  const plusMin = /([+-]?\d*\.?\d+(?:e[+-]\d+)?)\s*([+-])\s*([+-]?\d*\.?\d+(?:e[+-]\d+)?)/;
   const parentheses = /(\d)?\s*\(([^()]*)\)\s*/;
   var current;
-  while(eq.search(/^\s*([+-]?\d*\.?\d+)\s*$/)===-1){
+  while (eq.search(/^\s*([+-]?\d*\.?\d+(?:e[+-]\d+)?)\s*$/) === -1) {
     eq = fParentheses(eq);
-    if(eq===current) throw new SyntaxError('The equation is invalid.');
+    if (eq === current) return handleCallback(new SyntaxError('The equation is invalid.'), null);
     current = eq;
   }
-  return +eq;
+  return handleCallback(null, +eq);
 
-  function fParentheses(eq){
-    while(eq.search(parentheses)!==-1){
-      eq = eq.replace(parentheses,function(a,b,c){
+  function fParentheses(eq) {
+    while (eq.search(parentheses) !== -1) {
+      eq = eq.replace(parentheses, function (a, b, c) {
         c = fMulDiv(c);
         c = fPlusMin(c);
-        return typeof b==='string' ? `${b}*${c}`:c;
+        return typeof b === 'string' ? b + '*' + c : c;
       });
@@ -27,7 +27,8 @@ }
 
-  function fMulDiv(eq){
-    while(eq.search(mulDiv)!==-1){
-      eq = eq.replace(mulDiv,function(a){
+  function fMulDiv(eq) {
+    while (eq.search(mulDiv) !== -1) {
+      eq = eq.replace(mulDiv, function (a) {
         const sides = mulDiv.exec(a);
-        return sides[2]==='*' ? sides[1] * sides[3]:sides[1]/sides[3];
+        const result = sides[2] === '*' ? sides[1] * sides[3] : sides[1] / sides[3];
+        return result >= 0 ? '+' + result : result;
       });
@@ -38,8 +39,8 @@ }
 
-  function fPlusMin(eq){
-    eq = eq.replace(/([+-])([+-])(\d|\.)/g,function(a,b,c,d){return `${b===c ? '+':'-'}${d}`;});
-    while(eq.search(plusMin)!==-1){
-      eq = eq.replace(plusMin,function(a){
+  function fPlusMin(eq) {
+    eq = eq.replace(/([+-])([+-])(\d|\.)/g, function (a, b, c, d) { return (b === c ? '+' : '-') + d; });
+    while (eq.search(plusMin) !== -1) {
+      eq = eq.replace(plusMin, function (a) {
         const sides = plusMin.exec(a);
-        return sides[2]==='+' ? +sides[1] + +sides[3]:sides[1]-sides[3];
+        return sides[2] === '+' ? +sides[1] + +sides[3] : sides[1] - sides[3];
       });
@@ -50,2 +51,12 @@ }
 
+  function handleCallback(errObject, result) {
+    if (typeof callback !== 'function') {
+      if (errObject !== null) throw errObject;
+    } else {
+      callback(errObject, result);
+    }
+    return result;
+
+  }
+
 }
@@ -52,0 +63,0 @@

tests/arguments-tests.js

@@ -38,2 +38,38 @@ /* global expect */
 
+describe("When the module is executed with incorrect [non-String] first argument and [Function] second argument",function(){
+  beforeEach(function(){
+    this.callback = jasmine.createSpy('callback');
+    this.types = [
+      1,
+      true,
+      null,
+      {},
+      [],
+      /hello/,
+      ()=>{}
+    ];
+    this.stringMath = stringMath;
+  });
+
+  it('it should not throw an error',function(){
+    for(var type of this.types){
+      expect(this.stringMath.bind(this,type,function(){})).not.toThrowError();
+    }
+  });
+  it('it should call this function with error object as the first argument and result value equal to null as the second argument',function(){
+    for(var type of this.types){
+      expect(this.stringMath.bind(this,type,this.callback)).not.toThrowError();
+      expect(this.callback).toHaveBeenCalled();
+      expect(this.callback).toHaveBeenCalledWith(jasmine.any(Error), null);
+    }
+  });
+
+  it('it should return null',function(){
+    for(var type of this.types){
+      expect(this.stringMath(type,function(){})).toEqual(null);
+    }
+  });
+
+});
+
 describe("When the module is executed with correct [String] argument",function(){
@@ -49,2 +85,24 @@ beforeEach(function(){
 
+describe("When the module is executed with correct [String] first argument and [Function] second argument",function(){
+  beforeEach(function(){
+    this.callback = jasmine.createSpy('callback');
+    this.stringMath = stringMath;
+  });
+
+  it('it should not throw an error',function(){
+    expect(this.stringMath.bind(this,'2+2',function(){})).not.toThrowError();
+  });
+
+  it('it should call this function with null as the first argument and [Number] result value as the second argument',function(){
+    expect(this.stringMath.bind(this,'2+2',this.callback)).not.toThrowError();
+    expect(this.callback).toHaveBeenCalled();
+    expect(this.callback).toHaveBeenCalledWith(null,jasmine.any(Number));
+  });
+
+  it('it should return [Number] value',function(){
+    expect(this.stringMath('2+2',function(){})).toEqual(jasmine.any(Number));
+  });
+
+});
+
 describe("When the module is executed with correct [String] argument but incorrect arithmetical formula",function(){
@@ -61,2 +119,32 @@ beforeEach(function(){
   });
+});
+
+describe("When the module is executed with correct [String] first argument but of incorrect arithmetical formula and [Function] second argument",function(){
+  beforeEach(function(){
+    this.callback = jasmine.createSpy('callback');
+    this.incorrectList = incorrects;
+    this.stringMath = stringMath;
+  });
+
+  it('it should not throw an error',function(){
+    for(var incorrect of this.incorrectList){
+      expect(this.stringMath.bind(this,incorrect,function(){})).not.toThrowError();
+    }
+  });
+
+  it('it should call this function with error object as the first argument and result value equal to null as the second argument',function(){
+    for(var incorrect of this.incorrectList){
+      expect(this.stringMath.bind(this,incorrect,this.callback)).not.toThrowError();
+      expect(this.callback).toHaveBeenCalled();
+      expect(this.callback).toHaveBeenCalledWith(jasmine.any(Error), null);
+    }
+  });
+
+  it('it should return null',function(){
+    for(var incorrect of this.incorrectList){
+      expect(this.stringMath(incorrect,function(){})).toEqual(null);
+    }
+  });
+
+
 });

tests/incorrects.js

@@ -22,3 +22,13 @@ module.exports = [
   '3(/5)',
-  '3-(*6)'
+  '3-(*6)',
+  'e5',
+  'e+5',
+  'e-5',
+  '3e+',
+  '3e-',
+  '.4e+3.2',
+  '1.5e-1.25',
+  '2 e+3',
+  '2e +3',
+  '2e + 3'
 ];

tests/scenarios.js

@@ -60,2 +60,7 @@ module.exports = [
   {expression:"-2*-2",result:4},
+  {expression:"5-1*-1",result:6},
+  {expression:"5+-1*-1",result:6},
+  {expression:"5 + -1 * -1",result:6},
+  {expression:"5--1*-1",result:4},
+  {expression:"5 - -1 * -1",result:4},
   {expression:"(-2)*(-2)",result:4},
@@ -126,3 +131,24 @@ {expression:"-2*2",result:-4},
   {expression:"3.5+5(-4-(3/(3+1)-12*3-.2*22)-16/4*12-5/(2)+3.5+2.5(1.5-2*7))-16",result:-225.5},
-  {expression:"12.436 - (2.15-1.6/.1) * (-8.33+(3   -1 *1.11)/  (3/(2.19+    .7*1)/1)+1)-11.5",result:-75.367805}
+  {expression:"12.436 - (2.15-1.6/.1) * (-8.33+(3   -1 *1.11)/  (3/(2.19+    .7*1)/1)+1)-11.5",result:-75.367805},
+  {expression:"1e-2",result:0.01},
+  {expression:".1e-2",result:0.001},
+  {expression:"1.234e+5",result:123400},
+  {expression:"1e-2+1e+2",result:100.01},
+  {expression:"1e-2 + 1e+2",result:100.01},
+  {expression:".2e-3 / 2e-5",result:10},
+  {expression:".1*1e+5*(.25e-5/.5)",result:0.05},
+  {expression:"1234567890000*1234567890000",result:1.524157875019052e+24},
+  {expression:"1/1000000",result:0.000001},
+  {expression:"1/10000000",result:1e-7},
+  {expression:"1/100000000",result:1e-8},
+  {expression:"1/1000000000",result:1e-9},
+  {expression:".25/123456789",result:2.0250000184275003e-9},
+  {expression:"123/-.25e-50",result:-4.92e+52},
+  {expression:"1.45*0e+10",result:0},
+  {expression:"0.055/(-5e-5)",result:-1100},
+  {expression:"5e+5*2e-3+5e+2/5e-4",result:1001000},
+  {expression:".5e+123 * .25e-123",result:0.125},
+  {expression:"(2e+2)",result:200},
+  {expression:"123/1000/2000/3000",result:2.05e-8},
+  {expression:"(2.5e-2*(.25e+2*(.05e+5*5e-2)))",result:156.25}
 ];

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Improved metrics

Total package byte prevSize

20302

increased by42.22%

Lines of code

399

increased by41.99%

Number of lines in readme file

116

increased by18.37%

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