Add is.inRange() (#3)

index.js

@@ -150,4 +150,12 @@ const typedArrayTypes = new Set([
 ]);
 is.typedArray = x => typedArrayTypes.has(getObjectType(x));
 
+is.inRange = (x, range) => {
+	if (is.number(range)) {
+		return (x >= Math.min(0, range)) && (x <= Math.max(range, 0));
+	}
+
+	return (is.array(range)) && (x >= Math.min.apply(Math, range)) && (x <= Math.max.apply(Math, range));
+};
+
 module.exports = is;

readme.md

@@ -121,6 +121,13 @@ Returns `true` for instances created by a ES2015 class.
 
 ##### .typedArray(value)
 
+##### .inRange(value, range)
+
+Check to see if the value is within a given range, for example `is.inRange(3, [0, 5])`.
+The range supplied can be an array of any size, though this will only check for
+the minimum and maximum values in it.
+
+If `range` is a number (e.g., `is.inRange(3, 10)`), it will be treated as a range of 0 to `range`.
 
 ## FAQ
 

test.js

@@ -305,3 +305,16 @@ test('is.typedArray', t => {
 	t.false(m.typedArray([]));
 	t.false(m.typedArray({}));
 });
+
+test('is.inRange', t => {
+	const x = 3;
+
+	t.true(m.inRange(x, [0, 5]));
+	t.true(m.inRange(x, [5, 0]));
+	t.true(m.inRange(x, [-5, 5]));
+	t.true(m.inRange(x, [5, -5]));
+	t.false(m.inRange(x, [4, 8]));
+
+	t.true(m.inRange(x, 10));
+	t.false(m.inRange(x, 2));
+});