fix(circuit): allow timeout option to be false (#396)

* fix(circuit): allow timeout option to be false

Allow `false` to be provided for the `timeout` option as a means of
disabling the entire feature.

Fixes #393.

* test: timeout=false option

lib/circuit.js

@@ -32,7 +32,8 @@ Please use options.errorThresholdPercentage`;
  * @param {Function} action The action to fire for this {@link CircuitBreaker}
  * @param {Object} options Options for the {@link CircuitBreaker}
  * @param {Number} options.timeout The time in milliseconds that action should
- * be allowed to execute before timing out. Default 10000 (10 seconds)
+ * be allowed to execute before timing out. Timeout can be disabled by setting
+ * this to `false`. Default 10000 (10 seconds)
  * @param {Number} options.maxFailures (Deprecated) The number of times the
  * circuit can fail before opening. Default 10.
  * @param {Number} options.resetTimeout The time in milliseconds to wait before
@@ -112,7 +113,8 @@ class CircuitBreaker extends EventEmitter {
   constructor (action, options = {}) {
     super();
     this.options = options;
-    this.options.timeout = options.timeout || 10000;
+    this.options.timeout =
+      options.timeout === false ? false : options.timeout || 10000;
     this.options.resetTimeout = options.resetTimeout || 30000;
     this.options.errorThresholdPercentage =
       options.errorThresholdPercentage || 50;

test/test.js

@@ -931,6 +931,30 @@ test('CircuitBreaker default capacity', t => {
   t.end();
 });
 
+test('CircuitBreaker without a timeout', t => {
+  t.plan(1);
+
+  const breaker = new CircuitBreaker(identity, { timeout: false });
+  const origTimeout = setTimeout;
+  let spyCalled = false;
+  // eslint-disable-next-line no-global-assign
+  setTimeout = () => {
+    spyCalled = true;
+  };
+
+  t.on('end', () => {
+    setTimeout = origTimeout; // eslint-disable-line no-global-assign
+  });
+
+  breaker.fire('foo')
+    .then(() => {
+      t.equals(spyCalled, false);
+      breaker.shutdown();
+      t.end();
+    })
+    .catch(t.fail);
+});
+
 const noop = _ => {};
 const common = require('./common');
 const identity = common.identity;