feat: expose cache.unset

Author: Federico De Giuli

README.md

@@ -202,3 +202,8 @@ When multiple `getOrElse` calls concurrently encounter the same stale value, it
 This is done on a per-instance level, so if you create many cache instances reading and writing the same keys, you are asking for trouble.
 If you don't, the worst case is every process in your system fetching the value at once.
 Which should be a smaller number than the number of concurrent requests in most cases.
+
+### Cache.unset(key, cb) -> Promise
+
+Cache delete operation.
+`key` has to be a string.

lib/cache.js

@@ -127,4 +127,14 @@ Cache.prototype.getOrElse = function _getOrElse(rawKey, val, _opts, _cb) {
   return getOrElse(this, key, val, optsWithDefaults).nodeify(args.cb);
 };
 
+Cache.prototype.unset = function unset(rawKey, cb) {
+  var key = this.applyPrefix(rawKey);
+
+  return this._unset(key).nodeify(args.cb);
+};
+
+Cache.prototype._unset = function _unset(key) {
+  return this._applyTimeout(this.backend.unset(key));
+};
+
 module.exports = Cache;

test/get-set.test.js

@@ -3,7 +3,7 @@ import Bluebird from 'bluebird';
 
 import withBackends from './_backends';
 
-describe('Cache::{get,set}', () => {
+describe('Cache::{get,set,unset}', () => {
   withBackends(cache => {
     it('get/set (callback style)', done => {
       cache.set('callback-key', 'callback-value', setError => {
@@ -26,6 +26,32 @@ describe('Cache::{get,set}', () => {
       assert.equal('promise-value', await cache.get('promise-key'));
     });
 
+
+    it('set/unset (callback style', done => {
+      cache.set('callback-key', 'callback-value', setError => {
+        if (setError) return done(setError);
+        cache.unset('callback-key', unsetError => {
+          if (unsetError) return done(unsetError);
+          cache.get('callback-key', (getError, value) => {
+            if (getError) return done(getError);
+            let assertError = null;
+            try {
+              assert.equal(null, value);
+            } catch (error) {
+              assertError = error;
+            }
+            done(assertError);
+          });
+        });
+      });
+    });
+
+    it('set/unset (promise style)', async () => {
+      await cache.set('promise-key', 'promise-value', { expire: 1 });
+      await cache.unset('promise-key');
+      assert.equal(null, await cache.get('promise-key'));
+    });
+
     it('honors expires', async () => {
       const values = {
         key1: 'Value 1',