[BUGFIX] #344 minumum(0, -0) should be -0

MikeMcl · MikeMcl · commit 981a8a9c623d · 2023-04-23T14:58:39.000+01:00
diff --git a/bignumber.js b/bignumber.js
@@ -637,7 +637,7 @@
      * arguments {number|string|BigNumber}
      */
     BigNumber.maximum = BigNumber.max = function () {
-      return maxOrMin(arguments, P.lt);
+      return maxOrMin(arguments, -1);
     };
 
 
@@ -647,7 +647,7 @@
      * arguments {number|string|BigNumber}
      */
     BigNumber.minimum = BigNumber.min = function () {
-      return maxOrMin(arguments, P.gt);
+      return maxOrMin(arguments, 1);
     };
 
 
@@ -1291,24 +1291,20 @@
 
 
     // Handle BigNumber.max and BigNumber.min.
-    function maxOrMin(args, method) {
-      var n,
+    // If any number is NaN, return NaN.
+    function maxOrMin(args, n) {
+      var k, y,
         i = 1,
-        m = new BigNumber(args[0]);
+        x = new BigNumber(args[0]);
 
       for (; i < args.length; i++) {
-        n = new BigNumber(args[i]);
-
-        // If any number is NaN, return NaN.
-        if (!n.s) {
-          m = n;
-          break;
-        } else if (method.call(m, n)) {
-          m = n;
+        y = new BigNumber(args[i]);
+        if (!y.s || (k = compare(x, y)) === n || k === 0 && x.s === n) {
+          x = y;
         }
       }
 
-      return m;
+      return x;
     }
 
 
diff --git a/bignumber.mjs b/bignumber.mjs
@@ -634,7 +634,7 @@ function clone(configObject) {
    * arguments {number|string|BigNumber}
    */
   BigNumber.maximum = BigNumber.max = function () {
-    return maxOrMin(arguments, P.lt);
+    return maxOrMin(arguments, -1);
   };
 
 
@@ -644,7 +644,7 @@ function clone(configObject) {
    * arguments {number|string|BigNumber}
    */
   BigNumber.minimum = BigNumber.min = function () {
-    return maxOrMin(arguments, P.gt);
+    return maxOrMin(arguments, 1);
   };
 
 
@@ -1288,24 +1288,20 @@ function clone(configObject) {
 
 
   // Handle BigNumber.max and BigNumber.min.
-  function maxOrMin(args, method) {
-    var n,
+  // If any number is NaN, return NaN.
+  function maxOrMin(args, n) {
+    var k, y,
       i = 1,
-      m = new BigNumber(args[0]);
+      x = new BigNumber(args[0]);
 
     for (; i < args.length; i++) {
-      n = new BigNumber(args[i]);
-
-      // If any number is NaN, return NaN.
-      if (!n.s) {
-        m = n;
-        break;
-      } else if (method.call(m, n)) {
-        m = n;
+      y = new BigNumber(args[i]);
+      if (!y.s || (k = compare(x, y)) === n || k === 0 && x.s === n) {
+        x = y;
       }
     }
 
-    return m;
+    return x;
   }
 
 
diff --git a/test/methods/minmax.js b/test/methods/minmax.js
@@ -16,6 +16,30 @@ Test('minimum and maximum', function () {
     Test.areEqual(BigNumber.maximum, BigNumber.max);
     Test.areEqual(BigNumber.minimum, BigNumber.min);
 
+    function isMinusZero(x) {
+        return x.isZero() && x.isNegative();
+    }
+
+    t(isMinusZero(BigNumber.min(-0, 0)));
+    t(isMinusZero(BigNumber.min(0, -0)));
+    t(isMinusZero(BigNumber.min('-0', '0')));
+    t(isMinusZero(BigNumber.min('0', '-0')));
+    t(isMinusZero(BigNumber.min(-0, 1, 0, 2)));
+    t(isMinusZero(BigNumber.min(0, 1, 2, -0)));
+    t(isMinusZero(BigNumber.min(2, 1, -0, 0)));
+
+    function isPositiveZero(x) {
+        return x.isZero() && x.isPositive();
+    }
+
+    t(isPositiveZero(BigNumber.max(-0, 0)));
+    t(isPositiveZero(BigNumber.max(0, -0)));
+    t(isPositiveZero(BigNumber.max('-0', '0')));
+    t(isPositiveZero(BigNumber.max('0', '-0')));
+    t(isPositiveZero(BigNumber.max(0, -1, -0, -2)));
+    t(isPositiveZero(BigNumber.max(0, -1, 0, -2, -0)));
+    t(isPositiveZero(BigNumber.max(-0, -1, -2, -0, 0)));
+
     t(!BigNumber.min(0, 0, 0).isNaN());
     t(BigNumber.min(NaN, -2, 0, -1).isNaN());
     t(BigNumber.max(NaN, -2, 0, -1).isNaN());
