rand now supports decimals, tests updated

src/random.test.js

@@ -3,37 +3,72 @@ import { randBetween } from './utils/rand.js';
 
 describe('random', function () {
   it('should not return NaN', function () {
-    const num = randBetween(0, 100);
-    assert(!isNaN(num));
+    const r = randBetween(0, 100);
+    assert(!isNaN(r));
   });
-  it('should return type Number', function () {
-    const num = randBetween(0, 100);
-    assert.equal(typeof num, "number");
+  it('should return type number', function () {
+    const r = randBetween(0, 100);
+    assert.equal(typeof r, "number");
+  });
+  it('should be OK with min > max', function () {
+
+    let tries = 1000;
+
+    while (tries--) {
+      const r = randBetween(100, 0);
+      const lessThanMin = r < 0;
+      const moreThanMax = r > 100;
+      assert(!lessThanMin, r);
+      assert(!moreThanMax, r);
+    }
+  });
+  it('should be OK with decimals', function () {
+    const min = 0.1;
+    const max = 0.4;
+    const r = randBetween(min, max);
+    assert(r >= min, r);
+    assert(r <= max, r);
+  });
+  it('should be able to request decimals with whole bounds', function () {
+    const min = 1;
+    const max = 2;
+    let tries = 100;
+
+    let seenDecimal = false;
+    let r;
+    while (tries--) {
+      r = randBetween(min, max, true);
+      if (parseInt(r) !== r) {
+        seenDecimal = true;
+        break;
+      }
+    }
+    assert(seenDecimal, `min:${min}, max:${max}, r:${r}, tries:${99 - tries}`);
   });
   it('should be OK with negative numbers', function () {
-    const num = randBetween(-10, 0);
-    const lessThanMin = num < -10;
-    const moreThanMax = num > 0;
-    assert(!lessThanMin, num);
-    assert(!moreThanMax, num);
+    const r = randBetween(-10, 0);
+    const lessThanMin = r < -10;
+    const moreThanMax = r > 0;
+    assert(!lessThanMin, r);
+    assert(!moreThanMax, r);
   });
   it('should be OK with min 0 and max 1', function () {
-    const num = randBetween(0, 1);
-    const lessThanMin = num < 0;
-    const moreThanMax = num > 1;
-    assert(!lessThanMin, num);
-    assert(!moreThanMax, num);
+    const r = randBetween(0, 1);
+    const lessThanMin = r < 0;
+    const moreThanMax = r > 1;
+    assert(!lessThanMin, r);
+    assert(!moreThanMax, r);
   });
   it('should return a number between 0 and 100, 1000 times', function () {
 
     let tries = 1000;
 
     while (tries--) {
-      const num = randBetween(0, 100);
-      const lessThanMin = num < 0;
-      const moreThanMax = num > 100;
-      assert(!lessThanMin, num);
-      assert(!moreThanMax, num);
+      const r = randBetween(0, 100);
+      const lessThanMin = r < 0;
+      const moreThanMax = r > 100;
+      assert(!lessThanMin, r);
+      assert(!moreThanMax, r);
     }
   });
   it('should be inclusive of min and max (10,20)', function () {
@@ -42,9 +77,9 @@ describe('random', function () {
     let hadMax = false;
 
     while (tries-- && (!hadMin || !hadMax)) {
-      const num = randBetween(10, 20);
-      hadMin = hadMin || num === 10;
-      hadMax = hadMax || num === 20;
+      const r = randBetween(10, 20);
+      hadMin = hadMin || r === 10;
+      hadMax = hadMax || r === 20;
     }
 
     assert(hadMin, 'min');

src/utils/rand.js

@@ -1,5 +1,16 @@
-const randBetween = (min, max) => {
-  return Math.floor(Math.random() * (max + 1 - min)) + min;
+const randBetween = (min, max, decimal = false) => {
+
+  let floor = false;
+  // If min or max are both integers assume we want whole numbers only
+  if (!decimal && parseInt(min) === min && parseInt(max) === max) {
+    max += 1;
+    floor = true;
+  }
+  let rand = (Math.random() * (max - min)) + min;
+  if (floor) {
+    rand = Math.floor(rand);
+  }
+  return rand;
 }
 
 export {