Fix bug with negative numbers (#8)

sindresorhus · Jan 23, 2017 · 1b5e5d6 · 1b5e5d6
1 parent 105c356
commit 1b5e5d6
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diff --git a/index.js b/index.js
@@ -14,6 +14,10 @@ function round(fn, x, precision) {
 	var exponentNeg = precision > 0 ? 'e-' : 'e';
 	precision = Math.abs(precision);
 
+	if (fn === 'round') {
+		return Number(Math.sign(x) * (Math.round(Math.abs(x) + exponent + precision) + exponentNeg + precision));
+	}
+
 	return Number(Math[fn](x + exponent + precision) + exponentNeg + precision);
 }
 

diff --git a/test.js b/test.js
@@ -8,6 +8,7 @@ test('roundTo()', t => {
 	t.is(fn(1.005, 2), 1.01);
 	t.is(fn(1.005, 0), 1);
 	t.is(fn(111.1, -2), 100);
+	t.is(fn(-0.375, 2), -0.38);
 });
 
 test('roundTo.up()', t => {
@@ -17,6 +18,7 @@ test('roundTo.up()', t => {
 	t.is(fn.up(1.004, 2), 1.01);
 	t.is(fn.up(1.111, 0), 2);
 	t.is(fn.up(111.1, -2), 200);
+	t.is(fn.up(-0.375, 2), -0.37);
 });
 
 test('roundTo.down()', t => {
@@ -26,4 +28,5 @@ test('roundTo.down()', t => {
 	t.is(fn.down(1.006, 2), 1.00);
 	t.is(fn.down(1.006, 0), 1);
 	t.is(fn.down(111.6, -2), 100);
+	t.is(fn.down(-0.375, 2), -0.38);
 });