Add is.any() and is.all() methods (#19)

index.js

@@ -181,4 +181,31 @@ const isEmptyMapOrSet = x => (is.map(x) || is.set(x)) && x.size === 0;
 
 is.empty = x => !x || isEmptyStringOrArray(x) || isEmptyObject(x) || isEmptyMapOrSet(x);
 
+const predicateOnArray = (method, predicate, values) => {
+	// `values` is the calling function's "arguments object".
+	// We have to do it this way to keep node v4 support.
+	// So here we convert it to an array and slice off the first item.
+	values = Array.prototype.slice.call(values, 1);
+
+	if (is.function(predicate) === false) {
+		throw new TypeError(`Invalid predicate: ${util.inspect(predicate)}`);
+	}
+
+	if (values.length === 0) {
+		throw new TypeError(`Invalid number of values`);
+	}
+
+	return method.call(values, predicate);
+};
+
+// We have to use anonymous functions for the any() and all() methods
+// to get the arguments since we can't use rest parameters in node v4.
+is.any = function (predicate) {
+	return predicateOnArray(Array.prototype.some, predicate, arguments);
+};
+
+is.all = function (predicate) {
+	return predicateOnArray(Array.prototype.every, predicate, arguments);
+};
+
 module.exports = is;

readme.md

@@ -158,6 +158,30 @@ Check if `value` is `Infinity` or `-Infinity`.
 Returns `true` if `value` is falsy or an empty string, array, object, map, or set.
 
 
+##### .any(predicate, ...values)
+
+Returns `true` if **any** of the input `values` returns true in the `predicate`:
+
+```js
+is.any(is.string, {}, true, '🦄');
+//=> true
+
+is.any(is.boolean, 'unicorns', [], new Map());
+//=> false
+```
+
+##### .all(predicate, ...values)
+
+Returns `true` if **all** of the input `values` returns true in the `predicate`:
+
+```js
+is.all(is.object, {}, new Map(), new Set());
+//=> true
+
+is.all(is.string, '🦄', [], 'unicorns');
+//=> false
+```
+
 ## FAQ
 
 ### Why yet another type checking module?

test.js

@@ -427,3 +427,33 @@ test('is.empty', t => {
 	tempSet.add(1);
 	t.false(m.empty(tempSet));
 });
+
+test('is.any', t => {
+	t.true(m.any(m.string, {}, true, '🦄'));
+	t.true(m.any(m.object, false, {}, 'unicorns'));
+	t.false(m.any(m.boolean, '🦄', [], 3));
+	t.false(m.any(m.integer, true, 'lol', {}));
+
+	t.throws(() => {
+		m.any(null, true);
+	});
+
+	t.throws(() => {
+		m.any(m.string);
+	});
+});
+
+test('is.all', t => {
+	t.true(m.all(m.object, {}, new Set(), new Map()));
+	t.true(m.all(m.boolean, true, false));
+	t.false(m.all(m.string, '🦄', []));
+	t.false(m.all(m.set, new Map(), {}));
+
+	t.throws(() => {
+		m.all(null, true);
+	});
+
+	t.throws(() => {
+		m.all(m.string);
+	});
+});