Add immutability tests

test/modules/Decimal.js

@@ -15,7 +15,7 @@ if (typeof T === 'undefined') require('../setup');
   });
 
   var t = function (coefficient, exponent, sign, n) {
-        T.assertDecimal(coefficient, exponent, sign, new Decimal(n));
+    T.assertEqualProps(coefficient, exponent, sign, new Decimal(n));
   }
 
   t([0], 0, 1, 0);

test/modules/abs.js

@@ -4,9 +4,7 @@ if (typeof T === 'undefined') require('../setup');
   T('absoluteValue');
 
   function t(expected, value){
-        var x = new Decimal(value);
-        T.assertEqual(expected, x.abs().valueOf());
-        T.assert(x.eq(value) || x.isNaN());
+    T.assertEqual(expected, new Decimal(value).abs().valueOf());
   }
 
   Decimal.config({

test/modules/acos.js

@@ -6,7 +6,6 @@ if (typeof T === 'undefined') require('../setup');
   function t(n, pr, rm, expected) {
     Decimal.precision = pr;
     Decimal.rounding = rm;
-        T.assertEqual(expected, Decimal.acos(n).valueOf());
     T.assertEqual(expected, new Decimal(n).acos().valueOf());
   }
 

test/modules/acosh.js

@@ -6,7 +6,6 @@ if (typeof T === 'undefined') require('../setup');
   function t(n, pr, rm, expected) {
     Decimal.precision = pr;
     Decimal.rounding = rm;
-        T.assertEqual(expected, Decimal.acosh(n).valueOf());
     T.assertEqual(expected, new Decimal(n).acosh().valueOf());
   }
 

test/modules/asin.js

@@ -6,7 +6,6 @@ if (typeof T === 'undefined') require('../setup');
   function t(n, pr, rm, expected) {
     Decimal.precision = pr;
     Decimal.rounding = rm;
-        T.assertEqual(expected, Decimal.asin(n).valueOf());
     T.assertEqual(expected, new Decimal(n).asin().valueOf());
   }
 

test/modules/asinh.js

@@ -6,7 +6,6 @@ if (typeof T === 'undefined') require('../setup');
    function t(n, pr, rm, expected) {
     Decimal.precision = pr;
     Decimal.rounding = rm;
-        T.assertEqual(expected, Decimal.asinh(n).valueOf());
     T.assertEqual(expected, new Decimal(n).asinh().valueOf());
   }
 

test/modules/atan.js

@@ -6,7 +6,6 @@ if (typeof T === 'undefined') require('../setup');
   function t(n, pr, rm, expected) {
     Decimal.precision = pr;
     Decimal.rounding = rm;
-        T.assertEqual(expected, Decimal.atan(n).valueOf());
     T.assertEqual(expected, new Decimal(n).atan().valueOf());
   }
 

test/modules/atan2.js

@@ -48,7 +48,7 @@ if (typeof T === 'undefined') require('../setup');
   t('-Infinity', 'Infinity', 20, 4, '-0.78539816339744830962');
   t('-Infinity', '-Infinity', 20, 4, '-2.3561944901923449288');
 
-    // Fails (both 1 ulp)
+  // Fails (1 ulp)
   //t('5900', '7999999999999999999999999999999999999999199999999999999999999.99999', 4, 1, '0.0000000000000000000000000000000000000000000000000000000007375');
   //t('5999999.9999999999999999999999999999999999999999999998', '599999999999999999999999989999999999999999999999999999999999999999999999999999999999999999999999999999999999999999959999999999999999999999999999999999999999999999999999999999999999999999999999999999999999.9999999999999999999999999999999999999999999', 2, 2, '0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000011');
 

test/modules/atanh.js

@@ -6,7 +6,6 @@ if (typeof T === 'undefined') require('../setup');
   function t(n, pr, rm, expected) {
     Decimal.precision = pr;
     Decimal.rounding = rm;
-        T.assertEqual(expected, Decimal.atanh(n).valueOf());
     T.assertEqual(expected, new Decimal(n).atanh().valueOf());
   }
 

test/modules/cbrt.js

@@ -6,7 +6,6 @@ if (typeof T === 'undefined') require('../setup');
   function t(n, pr, rm, expected) {
     Decimal.precision = pr;
     Decimal.rounding = rm;
-        T.assertEqual(expected, Decimal.cbrt(n).valueOf());
     T.assertEqual(expected, new Decimal(n).cbrt().valueOf());
   }
 

test/modules/ceil.js

@@ -4,7 +4,6 @@ if (typeof T === 'undefined') require('../setup');
   T('ceil');
 
   function t(expected, n) {
-        T.assertEqual(expected, Decimal.ceil(n).valueOf());
     T.assertEqual(expected, new Decimal(n).ceil().valueOf());
   }
 

test/modules/cmp.js

@@ -7,7 +7,6 @@ if (typeof T === 'undefined') require('../setup');
 
   function t(a, b, expected) {
     T.assertEqual(expected, new Decimal(a).comparedTo(b));
-        //T.assertEqual(expected, new Decimal(a).cmp(b));
   }
 
   Decimal.config({

test/modules/config.js

@@ -23,9 +23,6 @@ if (typeof T === 'undefined') require('../setup');
     minE       {number} [-EXP_LIMIT, 0]
     modulo     {number} [0, 9]
     crypto     {boolean|number} {true, false, 1, 0}
-      isExpBin   {boolean|number} {true, false, 1, 0}
-      isExpHex   {boolean|number} {true, false, 1, 0}
-      isExpOct   {boolean|number} {true, false, 1, 0}
   */
 
   t(Decimal.config({}) === Decimal);

test/modules/cos.js

@@ -6,10 +6,7 @@ if (typeof T === 'undefined') require('../setup');
   function t(n, pr, rm, expected) {
     Decimal.precision = pr;
     Decimal.rounding = rm;
-        var x = new Decimal(n);
-        T.assertEqual(expected, x.cos().valueOf());
-        T.assertEqual(expected, Decimal.cos(n).valueOf());
-        T.assert(x.eq(n) || x.isNaN());
+    T.assertEqual(expected, new Decimal(n).cos().valueOf());
   }
 
   Decimal.config({
@@ -42,7 +39,6 @@ if (typeof T === 'undefined') require('../setup');
   t('0.3834777777', 3, 4, '0.927');
   t('16355.3334', 9, 4, '0.979658167');
   t('0.997737586545708065463833973312637902054356957830033', 5, 5, '0.5422');
-    t('-0.997737586545708065463833973312637902054356957830033', 5, 5, '0.5422');
   t('7803700', 4, 2, '-0.9032');
   t('841822094288189413002174891207354317', 5, 2, '-0.86017');
   t('67942', 8, 3, '-0.33958641');

test/modules/cosh.js

@@ -6,7 +6,6 @@ if (typeof T === 'undefined') require('../setup');
   function t(n, pr, rm, expected) {
     Decimal.precision = pr;
     Decimal.rounding = rm;
-        T.assertEqual(expected, Decimal.cosh(n).valueOf());
     T.assertEqual(expected, new Decimal(n).cosh().valueOf());
   }
 

test/modules/div.js

@@ -124,7 +124,6 @@ if (typeof T === 'undefined') require('../setup');
     Decimal.precision = sd;
     Decimal.rounding = rm;
     T.assertEqual(expected, new Decimal(dividend).div(divisor).valueOf());
-        //T.assertEqual(expected, new Decimal(dividend).div(new Decimal(divisor)).valueOf());
   }
 
   t('999.5', 1, '1000', 3, 0);

test/modules/exp.js

@@ -6,10 +6,7 @@ if (typeof T === 'undefined') require('../setup');
   function t(n, expected, pr, rm) {
     Decimal.precision = pr;
     Decimal.rounding = rm;
-        var x = new Decimal(n);
-        T.assertEqual(expected, x.exp().valueOf());
-        T.assertEqual(expected, Decimal.exp(n).valueOf());
-        T.assert(x.eq(n) || x.isNaN());
+    T.assertEqual(expected, new Decimal(n).exp().valueOf());
   }
 
   Decimal.config({

test/modules/floor.js

@@ -4,7 +4,6 @@ if (typeof T === 'undefined') require('../setup');
   T('floor');
 
   function t(expected, n) {
-        T.assertEqual(expected,  Decimal.floor(n).valueOf());
     T.assertEqual(expected, new Decimal(n).floor().valueOf());
   }
 

test/modules/fromJSON.js

@@ -4,7 +4,6 @@ if (typeof T === 'undefined') require('../setup');
   T('fromJSON');
 
   Decimal.config({
-        //crypto: true,
     precision: Math.random() * 40 + 1 | 0,
     rounding: Math.random() * 9 | 0,
     toExpNeg: -7,
@@ -25,21 +24,19 @@ if (typeof T === 'undefined') require('../setup');
     // Change exponent to a non-zero value of random length in the range (-9e15, 9e15).
     r = new Decimal(e.slice(0, e.indexOf('e') + 1) + ( Math.random() < 0.5 ? '-' : '' ) +
       ( n = Math.floor( Math.random() * 9e15 ) + '' ).slice( Math.random() * n.length | 0 ));
-          //( n = Math.floor( Math.random() * 40 ) + '' ).slice( Math.random() * n.length | 0 ));
-
     //console.log(r.toString());
 
     toJ = r.toJSON();
-        //console.log(' toJ:   ' + toJ);
+    //console.log(' toJSON:   ' + toJ);
 
     fromJ = Decimal.fromJSON(toJ);
-        //console.log(' fromJ:   ' + fromJ);
+    //console.log(' fromJSON: ' + fromJ);
 
     /*
     if (!r.eq(fromJ)) {
       console.error(' r:        ' + r);
-            console.error(' toJ:   ' + toJ);
-            console.error(' fromJ: ' + fromJ);
+      console.error(' toJSON:   ' + toJ);
+      console.error(' fromJSON: ' + fromJ);
     }
     */
     T.assert(r.eq(fromJ));

test/modules/immutability.js

@@ -0,0 +1,561 @@
+// Tests immutability of operand[s] for all applicable methods.
+// Also tests each Decimal.prototype method against its equivalent Decimal method where applicable.
+if (typeof T === 'undefined') require('../setup');
+
+(function () {
+  T('immutability');
+
+  Decimal.config({
+    precision: 20,
+    rounding: 4,
+    toExpNeg: -7,
+    toExpPos: 21,
+    minE: -9e15,
+    maxE: 9e15
+  });
+
+  // Integer [0, 9e15), with each possible number of digits, [1, 16], equally likely.
+  function randInt() {
+    return Math.floor(Math.random() * 9e15 / Math.pow(10, Math.random() * 16 | 0));
+  }
+
+  var a, aa, b, bb, i, k, n, t, v, x, y, z;
+
+  t = T.assertEqualDecimal;
+
+  v = [
+    0,
+    NaN,
+    Infinity,
+    -Infinity,
+    0.5,
+    -0.5,
+    1,
+    -1,
+    (x = Decimal.random()),
+    x.neg(),
+    (x = randInt()),
+    -x,
+    (x = Decimal.random().plus(randInt())),
+    x.neg()
+  ];
+
+  for (i = 0; i < v.length; i++) {
+    a = new Decimal(v[i]);
+    aa = new Decimal(v[i]);
+    k = (Math.random() * 10 | 0) / 10;
+    b = k == 0.5 ? new Decimal(a) : a[k < 0.5 ? 'plus' : 'minus'](Decimal.random().plus(randInt()));
+    bb = new Decimal(b);
+    n = Math.random() * 20 + 1 | 0;
+
+    x = a.absoluteValue();
+    t(a, aa);
+    y = a.abs();
+    t(a, aa);
+    z = Decimal.abs(a);
+    t(a, aa);
+
+    t(x, y);
+    t(y, z);
+
+    x = a.ceil();
+    t(a, aa);
+    y = Decimal.ceil(a);
+    t(a, aa);
+
+    t(x, y);
+
+    x = a.comparedTo(b);
+    t(a, aa);
+    t(b, bb);
+    y = a.cmp(b);
+    t(a, aa);
+    t(b, bb);
+
+    T.assertEqual(x, y);
+
+    x = a.cosine();
+    t(a, aa);
+    y = a.cos();
+    t(a, aa);
+    z = Decimal.cos(a);
+    t(a, aa);
+
+    t(x, y);
+    t(y, z);
+
+    x = a.cubeRoot();
+    t(a, aa);
+    y = a.cbrt();
+    t(a, aa);
+    z = Decimal.cbrt(a);
+    t(a, aa);
+
+    t(x, y);
+    t(y, z);
+
+    x = a.decimalPlaces();
+    t(a, aa);
+    y = a.dp();
+    t(a, aa);
+
+    T.assertEqual(x, y);
+
+    x = a.dividedBy(b);
+    t(a, aa);
+    t(b, bb);
+    y = a.div(b);
+    t(a, aa);
+    t(b, bb);
+    z = Decimal.div(a, b);
+    t(a, aa);
+    t(b, bb);
+
+    t(x, y);
+    t(y, z);
+
+    x = a.dividedToIntegerBy(b);
+    t(a, aa);
+    t(b, bb);
+    y = a.divToInt(b);
+    t(a, aa);
+    t(b, bb);
+
+    t(x, y);
+
+    x = a.equals(b);
+    t(a, aa);
+    t(b, bb);
+    y = a.eq(b);
+    t(a, aa);
+    t(b, bb);
+
+    T.assertEqual(x, y);
+
+    x = a.floor();
+    t(a, aa);
+    y = Decimal.floor(a);
+    t(a, aa);
+
+    t(x, y);
+
+    x = a.greaterThan(b);
+    t(a, aa);
+    t(b, bb);
+    y = a.gt(b);
+    t(a, aa);
+    t(b, bb);
+
+    T.assertEqual(x, y);
+
+    x = a.greaterThanOrEqualTo(b);
+    t(a, aa);
+    t(b, bb);
+    y = a.gte(b);
+    t(a, aa);
+    t(b, bb);
+
+    T.assertEqual(x, y);
+
+    // Omit these hyperbolic methods if a is large, as they are too time-consuming.
+    if (a.abs().lt(1000)) {
+      x = a.hyperbolicCosine();
+      t(a, aa);
+      y = a.cosh();
+      t(a, aa);
+      z = Decimal.cosh(a);
+      t(a, aa);
+
+      t(x, y);
+      t(y, z);
+
+      x = a.hyperbolicSine();
+      t(a, aa);
+      y = a.sinh();
+      t(a, aa);
+      z = Decimal.sinh(a);
+      t(a, aa);
+
+      t(x, y);
+      t(y, z);
+
+      x = a.hyperbolicTangent();
+      t(a, aa);
+      y = a.tanh();
+      t(a, aa);
+      z = Decimal.tanh(a);
+      t(a, aa);
+
+      t(x, y);
+      t(y, z);
+    }
+
+    // a [-1, 1]
+    x = a.inverseCosine();
+    t(a, aa);
+    y = a.acos();
+    t(a, aa);
+    z = Decimal.acos(a);
+    t(a, aa);
+
+    t(x, y);
+    t(y, z);
+
+    // a [1, Infinity]
+    x = a.inverseHyperbolicCosine();
+    t(a, aa);
+    y = a.acosh();
+    t(a, aa);
+    z = Decimal.acosh(a);
+    t(a, aa);
+
+    t(x, y);
+    t(y, z);
+
+    x = a.inverseHyperbolicSine();
+    t(a, aa);
+    y = a.asinh();
+    t(a, aa);
+    z = Decimal.asinh(a);
+    t(a, aa);
+
+    t(x, y);
+    t(y, z);
+
+    // a [-1, 1]
+    x = a.inverseHyperbolicTangent();
+    t(a, aa);
+    y = a.atanh();
+    t(a, aa);
+    z = Decimal.atanh(a);
+    t(a, aa);
+
+    t(x, y);
+    t(y, z);
+
+    // a [-1, 1]
+    x = a.inverseSine();
+    t(a, aa);
+    y = a.asin();
+    t(a, aa);
+    z = Decimal.asin(a);
+    t(a, aa);
+
+    t(x, y);
+    t(y, z);
+
+    x = a.inverseTangent();
+    t(a, aa);
+    y = a.atan();
+    t(a, aa);
+    z = Decimal.atan(a);
+    t(a, aa);
+
+    t(x, y);
+    t(y, z);
+
+    a.isFinite();
+    t(a, aa);
+
+    x = a.isInteger();
+    t(a, aa);
+    y = a.isInt();
+    t(a, aa);
+
+    T.assertEqual(x, y);
+
+    a.isNaN();
+    t(a, aa);
+
+    x = a.isNegative();
+    t(a, aa);
+    y = a.isNeg();
+    t(a, aa);
+
+    T.assertEqual(x, y);
+
+    x = a.isPositive();
+    t(a, aa);
+    y = a.isPos();
+    t(a, aa);
+
+    T.assertEqual(x, y);
+
+    a.isZero();
+    t(a, aa);
+
+    x = a.lessThan(b);
+    t(a, aa);
+    t(b, bb);
+    y = a.lt(b);
+    t(a, aa);
+    t(b, bb);
+
+    T.assertEqual(x, y);
+
+    x = a.lessThanOrEqualTo(b);
+    t(a, aa);
+    t(b, bb);
+    y = a.lte(b);
+    t(a, aa);
+    t(b, bb);
+
+    T.assertEqual(x, y);
+
+    x = a.logarithm();
+    t(a, aa);
+    y = a.log();
+    t(a, aa);
+    z = Decimal.log(a);
+    t(a, aa);
+
+    t(x, y);
+    t(y, z);
+
+    x = a.minus(b);
+    t(a, aa);
+    t(b, bb);
+    y = a.sub(b);
+    t(a, aa);
+    t(b, bb);
+    z = Decimal.sub(a, b);
+    t(a, aa);
+    t(b, bb);
+
+    t(x, y);
+    t(y, z);
+
+    x = a.modulo(b);
+    t(a, aa);
+    t(b, bb);
+    y = a.mod(b);
+    t(a, aa);
+    t(b, bb);
+    z = Decimal.mod(a, b);
+    t(a, aa);
+    t(b, bb);
+
+    t(x, y);
+    t(y, z);
+
+    x = a.naturalExponential();
+    t(a, aa);
+    y = a.exp();
+    t(a, aa);
+    z = Decimal.exp(a);
+    t(a, aa);
+
+    t(x, y);
+    t(y, z);
+
+    x = a.naturalLogarithm();
+    t(a, aa);
+    y = a.ln();
+    t(a, aa);
+    z = Decimal.ln(a);
+    t(a, aa);
+
+    t(x, y);
+    t(y, z);
+
+    x = a.negated();
+    t(a, aa);
+    y = a.neg();
+    t(a, aa);
+
+    t(x, y);
+
+    x = a.plus(b);
+    t(a, aa);
+    t(b, bb);
+    y = a.add(b);
+    t(a, aa);
+    t(b, bb);
+    z = Decimal.add(a, b);
+    t(a, aa);
+    t(b, bb);
+
+    t(x, y);
+    t(y, z);
+
+    x = a.precision();
+    t(a, aa);
+    y = a.sd();
+    t(a, aa);
+
+    T.assertEqual(x, y);
+
+    x = a.round();
+    t(a, aa);
+    y = Decimal.round(a);
+    t(a, aa);
+
+    t(x, y);
+
+    x = a.sine();
+    t(a, aa);
+    y = a.sin();
+    t(a, aa);
+    z = Decimal.sin(a);
+    t(a, aa);
+
+    t(x, y);
+    t(y, z);
+
+    x = a.squareRoot();
+    t(a, aa);
+    y = a.sqrt();
+    t(a, aa);
+    z = Decimal.sqrt(a);
+    t(a, aa);
+
+    t(x, y);
+    t(y, z);
+
+    x = a.tangent();
+    t(a, aa);
+    y = a.tan();
+    t(a, aa);
+    z = Decimal.tan(a);
+    t(a, aa);
+
+    t(x, y);
+    t(y, z);
+
+    x = a.times(b);
+    t(a, aa);
+    t(b, bb);
+    y = a.mul(b);
+    t(a, aa);
+    t(b, bb);
+    z = Decimal.mul(a, b);
+    t(a, aa);
+    t(b, bb);
+
+    t(x, y);
+    t(y, z);
+
+    a.toBinary();
+    t(a, aa);
+
+    x = a.toDecimalPlaces(n);
+    t(a, aa);
+    y = a.toDP(n);
+    t(a, aa);
+
+    t(x, y);
+
+    a.toExponential(n);
+    t(a, aa);
+
+    a.toFixed(n);
+    t(a, aa);
+
+    a.toFraction();
+    t(a, aa);
+
+    x = a.toHexadecimal();
+    t(a, aa);
+    y = a.toHex();
+    t(a, aa);
+
+    T.assertEqual(x, y);
+
+    a.toJSON();
+    t(a, aa);
+
+    a.toNearest(b);
+    t(a, aa);
+    t(b, bb);
+
+    a.toNumber();
+    t(a, aa);
+
+    a.toOctal();
+    t(a, aa);
+
+    x = a.toPower(b);
+    t(a, aa);
+    t(b, bb);
+    y = a.pow(b);
+    t(a, aa);
+    t(b, bb);
+    z = Decimal.pow(a, b);
+    t(a, aa);
+    t(b, bb);
+
+    t(x, y);
+    t(y, z);
+
+    a.toPrecision(n);
+    t(a, aa);
+
+    x = a.toSignificantDigits(n);
+    t(a, aa);
+    y = a.toSD(n);
+    t(a, aa);
+
+    t(x, y);
+
+    a.toString();
+    t(a, aa);
+
+    x = a.truncated();
+    t(a, aa);
+    y = a.trunc();
+    t(a, aa);
+    z = Decimal.trunc(a);
+    t(a, aa);
+
+    t(x, y);
+    t(y, z);
+
+    a.valueOf();
+    t(a, aa);
+
+    Decimal.atan2(a, b);
+    t(a, aa);
+    t(b, bb);
+
+
+    Decimal.hypot(a, b);
+    t(a, aa);
+    t(b, bb);
+
+    x = Decimal.log(a, 10);
+    t(a, aa);
+    y = Decimal.log10(a);
+    t(a, aa);
+
+    t(x, y);
+
+    x = Decimal.log(a, 2);
+    t(a, aa);
+    y = Decimal.log2(a);
+    t(a, aa);
+
+    t(x, y);
+
+    Decimal.max(a, b);
+    t(a, aa);
+    t(b, bb);
+
+    Decimal.min(a, b);
+    t(a, aa);
+    t(b, bb);
+
+    Decimal.sign(a);
+    t(a, aa);
+  }
+
+  T.stop();
+})();
+
+/*
+// All methods tested above except:
+Decimal.clone();
+Decimal.config();
+Decimal.fromJSON();
+Decimal.noConflict();
+Decimal.random();
+*/

test/modules/intPow.js

@@ -3,9 +3,8 @@ if (typeof T === 'undefined') require('../setup');
 (function () {
   T('integer pow');
 
-    // Highest finite exponent is 100
+  // Highest finite exponent here is 100
   function t(expected, n, exp) {
-        T.assertEqual(expected, Decimal.pow(n, exp).valueOf());
     T.assertEqual(expected, new Decimal(n).pow(exp).valueOf());
   }
 

test/modules/ln.js

@@ -7,7 +7,6 @@ if (typeof T === 'undefined') require('../setup');
     Decimal.precision = sd;
     Decimal.rounding = rm;
     T.assertEqual(expected, new Decimal(n).ln().valueOf());
-        //T.assertEqual(expected, Decimal.ln(n).valueOf());
   }
 
   Decimal.config({

test/modules/log.js

@@ -7,7 +7,6 @@ if (typeof T === 'undefined') require('../setup');
     Decimal.precision = sd;
     Decimal.rounding = rm;
     T.assertEqual(expected, new Decimal(n).log(base).valueOf());
-        //T.assertEqual(expected, Decimal.log(n, base).valueOf());
   }
 
   Decimal.config({

test/modules/pow.js

@@ -6,7 +6,6 @@ if (typeof T === 'undefined') require('../setup');
   t = function (base, exp, expected, sd, rm) {
     Decimal.precision = sd;
     Decimal.rounding = rm;
-        T.assertEqual(expected, Decimal.pow(base, exp).valueOf());
     T.assertEqual(expected, new Decimal(base).pow(exp).valueOf());
   }
 

test/modules/powSqrt.js

@@ -19,7 +19,7 @@ if (typeof T === 'undefined') require('../setup');
     // Change exponent to a non-zero value of random length in the range (-9e15, 9e15).
     r = new Decimal(e.slice(0, e.indexOf('e') + 1) + ( Math.random() < 0.5 ? '-' : '' ) +
       ( n = Math.floor( Math.random() * 9e15 ) + '' ).slice( Math.random() * n.length | 0 ));
-        //T.write(' r:          ' + r);
+    //console.log(' r:          ' + r);
 
     // Random rounding mode.
     Decimal.rounding = Math.random() * 9 | 0;
@@ -28,11 +28,11 @@ if (typeof T === 'undefined') require('../setup');
     Decimal.precision = Math.random() * 40 + 1 | 0;
 
     p = r.pow(0.5);
-        //T.write(' r.pow(0.5): ' + p);
+    //console.log(' r.pow(0.5): ' + p);
 
     // sqrt is much faster than pow(0.5)
     s = r.sqrt();
-        //T.write(' r.sqrt():   ' + s);
+    //console.log(' r.sqrt():   ' + s);
 
     T.assertEqual(p.valueOf(), s.valueOf());
   }

test/modules/round.js

@@ -6,7 +6,6 @@ if (typeof T === 'undefined') require('../setup');
   function t(expected, n, rm) {
     Decimal.rounding = rm;
     T.assertEqual(expected, new Decimal(n).round().valueOf());
-        T.assertEqual(expected, Decimal.round(n).valueOf());
   }
 
   Decimal.config({

test/modules/sin.js

@@ -6,10 +6,7 @@ if (typeof T === 'undefined') require('../setup');
   function t(n, pr, rm, expected) {
     Decimal.precision = pr;
     Decimal.rounding = rm;
-        var x = new Decimal(n);
-        T.assertEqual(expected, x.sin().valueOf());
-        T.assertEqual(expected, Decimal.sin(n).valueOf());
-        T.assert(x.eq(n) || x.isNaN());
+    T.assertEqual(expected, new Decimal(n).sin().valueOf());
   }
 
   Decimal.config({
@@ -30,9 +27,6 @@ if (typeof T === 'undefined') require('../setup');
   t('93332358216', 48, 5, '0.000816283943127306029649893248669685836695194145277');
   t('766737078569022420173292205068953186848344673451240027655054631094318050', 18, 6, '0.00111135055272494455');
 
-    t('-93332358216', 48, 5, '-0.000816283943127306029649893248669685836695194145277');
-    t('-766737078569022420173292205068953186848344673451240027655054631094318050', 18, 6, '-0.00111135055272494455');
-
   t('0.359136383962093189473162700700590970518456985109181875257764726415814563424613193774806585890478208084275468196568294033', 38, 1, '0.35146584650000000000000000000000000006');
   t('3202222222227222222222222222222224222222222222222222222222.222222222222222222222222222', 7, 0, '0.5499568');
   t('8', 5, 6, '0.98936');

test/modules/sinh.js

@@ -6,7 +6,6 @@ if (typeof T === 'undefined') require('../setup');
   function t(n, pr, rm, expected) {
     Decimal.precision = pr;
     Decimal.rounding = rm;
-        T.assertEqual(expected, Decimal.sinh(n).valueOf());
     T.assertEqual(expected, new Decimal(n).sinh().valueOf());
   }
 

test/modules/sqrt.js

@@ -7,7 +7,6 @@ if (typeof T === 'undefined') require('../setup');
     Decimal.precision = sd;
     Decimal.rounding = rm;
     T.assertEqual(expected, new Decimal(n).sqrt().valueOf());
-        //T.assertEqual(expected, Decimal.sqrt(n).valueOf());
   }
 
   Decimal.config({

test/modules/tan.js

@@ -6,10 +6,7 @@ if (typeof T === 'undefined') require('../setup');
   function t(n, pr, rm, expected) {
     Decimal.precision = pr;
     Decimal.rounding = rm;
-        var x = new Decimal(n);
-        T.assertEqual(expected, x.tan().valueOf());
-        T.assertEqual(expected, Decimal.tan(n).valueOf());
-        T.assert(x.eq(n) || x.isNaN());
+    T.assertEqual(expected, new Decimal(n).tan().valueOf());
   }
 
   Decimal.config({
@@ -28,10 +25,8 @@ if (typeof T === 'undefined') require('../setup');
   t('-Infinity', 40, 4, 'NaN');
 
   t('3', 5, 5, '-0.14255');
-    t('-3', 5, 5, '0.14255');
   t('0.8', 7, 6, '1.029639');
   t('539998661123466984649191689138494900416386817996524', 7, 6, '32.04695');
-    t('-539998661123466984649191689138494900416386817996524', 7, 6, '-32.04695');
   t('0.5172293543584894071801901902', 5, 1, '0.56888');
   t('5', 10, 5, '-3.380515006');
   t('0.5283979979897015', 1, 4, '0.6');

test/modules/tanh.js

@@ -6,7 +6,6 @@ if (typeof T === 'undefined') require('../setup');
   function t(n, pr, rm, expected) {
     Decimal.precision = pr;
     Decimal.rounding = rm;
-        T.assertEqual(expected, Decimal.tanh(n).valueOf());
     T.assertEqual(expected, new Decimal(n).tanh().valueOf());
   }
 

test/modules/times.js

@@ -4,9 +4,7 @@ if (typeof T === 'undefined') require('../setup');
   T('times');
 
   var t = function (multiplicand, multiplier, expected) {
-        var x = new Decimal(multiplicand);
-        T.assertEqual(expected, x.times(multiplier).valueOf());
-        T.assert(x.eq(multiplicand) || x.isNaN());
+    T.assertEqual(expected, new Decimal(multiplicand).times(multiplier).valueOf());
   }
 
   Decimal.config({

test/modules/toFixed.js

@@ -20,13 +20,6 @@ if (typeof T === 'undefined') require('../setup');
     maxE: 9e15
   });
 
-    /*
-     https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Number/toFixed
-     JS:                    2.26.toFixed(5)  returns  2.26000
-     JS:                   -2.26.toFixed(5)  returns -2.26
-     Decimal:  new Decimal(-2.26).toFixed(5) returns -2.26000
-     */
-
   t('100.0', 99.9512986, 1);
   t('10.0',  9.95036, 1);
   t('1.0', 0.99, 1);

test/modules/trunc.js

@@ -5,7 +5,6 @@ if (typeof T === 'undefined') require('../setup');
 
   function t(expected, n) {
     T.assertEqual(expected, Decimal.trunc(n).valueOf());
-        T.assertEqual(expected, new Decimal(n).trunc().valueOf());
   }
 
   Decimal.config({

test/setup.js

@@ -36,7 +36,29 @@ T = (function () {
     }
   };
 
-  T.assertDecimal = function (digits, exponent, sign, n) {
+  T.assertEqual = function (expected, actual) {
+    ++testNumber;
+    if (expected === actual || expected !== expected && actual !== actual) {
+      ++passed;
+    } else {
+      writeError('\n Test number ' + testNumber + ' failed: assertEqual');
+      writeError(' Expected: ' + expected);
+      writeError(' Actual:   ' + actual);
+    }
+  };
+
+  T.assertEqualDecimal = function (x, y) {
+    ++testNumber;
+    if (x.eq(y) || x.isNaN() && y.isNaN()) {
+      ++passed;
+    } else {
+      writeError('\n Test number ' + testNumber + ' failed: assertEqualDecimal');
+      writeError(' x: ' + x.valueOf());
+      writeError(' y: ' + y.valueOf());
+    }
+  };
+
+  T.assertEqualProps = function (digits, exponent, sign, n) {
     var i = 0,
       len = digits.length;
     ++testNumber;
@@ -44,27 +66,13 @@ T = (function () {
     if (i === len && i === n.d.length && exponent === n.e && sign === n.s) {
       ++passed;
     } else {
-      writeError('\n Test number ' + testNumber + ' failed: assertDecimal');
+      writeError('\n Test number ' + testNumber + ' failed: assertEqualProps');
       writeError(' Expected digits:   ' + digits);
       writeError(' Expected exponent: ' + exponent);
       writeError(' Expected sign:     ' + sign);
       writeError(' Actual digits:     ' + n.d);
       writeError(' Actual exponent:   ' + n.e);
       writeError(' Actual sign:       ' + n.s);
-      //process.exit();
-    }
-  };
-
-  T.assertEqual = function (expected, actual) {
-    ++testNumber;
-    if (expected === actual || expected !== expected && actual !== actual) {
-      ++passed;
-      //write('\n Expected and actual: ' + actual);
-    } else {
-      writeError('\n Test number ' + testNumber + ' failed: assertEqual');
-      writeError(' Expected: ' + expected);
-      writeError(' Actual:   ' + actual);
-      //process.exit();
     }
   };
 
@@ -78,12 +86,10 @@ T = (function () {
     }
     if (actual instanceof Error && /DecimalError/.test(actual.message)) {
       ++passed;
-      //write('\n Expected and actual: ' + actual);
     } else {
       writeError('\n Test number ' + testNumber + ' failed: assertException');
       writeError(' Expected: ' + msg + ' to raise a [DecimalError].');
       writeError(' Actual:   ' + (actual || 'no exception'));
-      //process.exit();
     }
   };
 

test/test.html

@@ -41,6 +41,7 @@
       'exp',
       'floor',
       'hypot',
+      'immutability',
       'intPow',
       'isFiniteEtc',
       'ln',

test/test.js

@@ -27,6 +27,7 @@ console.log('\n Testing decimal.js\n');
     'exp',
     'floor',
    'hypot',
+   'immutability',
     'intPow',
     'isFiniteEtc',
     'ln',