Replace object outright when updates are constant

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## [unreleased]
 * Add `u.if` to conditionally update objects.
 * Add `u.map` to update all values in an array or object.
+* Replace object outright if null or constant givens as `updates`.
 
 ## [0.3.1]
 * Actually expose `u.in`.

lib/update.js

@@ -48,6 +48,10 @@ function update(updates, object) {
     return updates(object);
   }
 
+  if (updates === null || typeof updates !== 'object') {
+    return updates;
+  }
+
   const resolvedUpdates = resolveUpdates(updates, object);
 
   if (isEmpty(resolvedUpdates)) {

test/updeep-spec.js

@@ -37,6 +37,11 @@ describe('updeep', () => {
     expect(result).to.deep.equal([1, 7, 3]);
   });
 
+  it('replaces the object outright if updates are a constant', () => {
+    expect(u(3, {})).to.equal(3);
+    expect(u(null, {})).to.be.null;
+  });
+
   it('can add an element to an array', () => {
     const object = [];
     const result = u({ 0: 3 }, object);