test: add semaphore rate limiting test

Also removed two of the existing semaphore tests that were not really automated tests, but rather some debugging information about how the semaphore rate limiting works.
nodeshift · Jun 19, 2017 · b3d7b6f · b3d7b6f
1 parent 3d990c3
commit b3d7b6f
Show file tree

Hide file tree

Showing 3 changed files with 18 additions and 83 deletions.
diff --git a/lib/circuit.js b/lib/circuit.js
@@ -51,7 +51,7 @@ class CircuitBreaker extends EventEmitter {
     this.options.rollingCountTimeout = options.rollingCountTimeout || 10000;
     this.options.rollingCountBuckets = options.rollingCountBuckets || 10;
     this.options.rollingPercentilesEnabled = options.rollingPercentilesEnabled !== false;
-    this.options.capacity = options.capacity || 10;
+    this.options.capacity = typeof options.capacity === 'number' ? options.capacity : 10;
     this.semaphore = new Semaphore(this.options.capacity);
 
     this[STATUS] = new Status(this.options);

diff --git a/package.json b/package.json
@@ -63,7 +63,6 @@
     "jsdoc": "~3.4.2",
     "nsp": "~2.6.2",
     "opener": "~1.4.2",
-    "run-parallel": "^1.1.6",
     "standard-version": "^4.0.0",
     "szero": "^0.9.0",
     "tap-spec": "~4.1.1",

diff --git a/test/test.js b/test/test.js
@@ -719,89 +719,21 @@ test('Circuit Breaker timeout with semaphore released', (t) => {
   breaker.fire(-1).catch(() => {});
 });
 
-test('Semaphore capacity limit', (t) => {
-  t.plan(4);
-  const breaker = cb('foobar', { capacity: 1 });
-
-  breaker.fire()
-    .then(() => t.ok(true, `semaphore count is: ${breaker.semaphore.count} and initial capacity is: ${breaker.options.capacity}`))
-    .catch(t.fail)
-    .then(() => {
-      breaker.fire()
-      .then(() => t.ok(true, `semaphore count is: ${breaker.semaphore.count} and initial capacity is: ${breaker.options.capacity}`))
-      .catch(t.fail);
-    });
-  breaker.fire()
-    .then(() => t.ok(true, `semaphore count is: ${breaker.semaphore.count} and initial capacity is: ${breaker.options.capacity}`))
-    .catch(t.fail)
-    .then(() => {
-      breaker.fire()
-      .then(() => t.ok(true, `semaphore count is: ${breaker.semaphore.count} and initial capacity is: ${breaker.options.capacity}`))
-      .then(t.end)
-      .catch(t.fail);
-    });
-});
-
-test('Semaphore capacity limit in parallel', (t) => {
-  const parallel = require('run-parallel');
-  t.plan(24);
-  const breaker = cb('foobar', { capacity: 1 });
-
-  const tasks = [
-    () => {
-      breaker.fire()
-      .then((result) => {
-        t.ok(true, `semaphore count is: ${breaker.semaphore.count} and initial capacity is: ${breaker.options.capacity}`);
-        t.ok(true, `failures: ${breaker.stats.failures}`);
-        t.ok(true, `fallbacks: ${breaker.stats.fallbacks}`);
-        t.ok(true, `successes: ${breaker.stats.successes}`);
-        t.ok(true, `rejects: ${breaker.stats.rejects}`);
-        t.ok(true, `fires: ${breaker.stats.fires}`);
-      })
-      .catch(t.fail);
-    },
-    () => {
-      breaker.fire()
-      .then((result) => {
-        t.ok(true, `semaphore count is: ${breaker.semaphore.count} and initial capacity is: ${breaker.options.capacity}`);
-        t.ok(true, `failures: ${breaker.stats.failures}`);
-        t.ok(true, `fallbacks: ${breaker.stats.fallbacks}`);
-        t.ok(true, `successes: ${breaker.stats.successes}`);
-        t.ok(true, `rejects: ${breaker.stats.rejects}`);
-        t.ok(true, `fires: ${breaker.stats.fires}`);
-      })
-      .catch(t.fail);
-    },
-    () => {
-      breaker.fire()
-      .then((result) => {
-        t.ok(true, `semaphore count is: ${breaker.semaphore.count} and initial capacity is: ${breaker.options.capacity}`);
-        t.ok(true, `failures: ${breaker.stats.failures}`);
-        t.ok(true, `fallbacks: ${breaker.stats.fallbacks}`);
-        t.ok(true, `successes: ${breaker.stats.successes}`);
-        t.ok(true, `rejects: ${breaker.stats.rejects}`);
-        t.ok(true, `fires: ${breaker.stats.fires}`);
-      })
-      .catch(t.fail);
-    }
-  ];
+test('CircuitBreaker semaphore rate limiting', (t) => {
+  t.plan(2);
+  let timedOut = false;
+  const breaker = cb(timedFunction, { timeout: 300, capacity: 1 });
 
-  parallel(tasks, (error) => {
-    t.error(error);
-    t.fail();
+  // fire once to acquire the semaphore and hold it for a long time
+  breaker.fire(1000).catch(e => {
+    t.equals(e.code, 'ETIMEDOUT', 'Breaker timed out');
+    timedOut = true;
   });
 
-  breaker.fire()
-    .then((result) => {
-      t.ok(true, `This is not in parallel -> semaphore count is: ${breaker.semaphore.count} and initial capacity is: ${breaker.options.capacity}`);
-      t.ok(true, `failures: ${breaker.stats.failures}`);
-      t.ok(true, `fallbacks: ${breaker.stats.fallbacks}`);
-      t.ok(true, `successes: ${breaker.stats.successes}`);
-      t.ok(true, `rejects: ${breaker.stats.rejects}`);
-      t.ok(true, `fires: ${breaker.stats.fires}`);
-    })
-    .then(t.end)
-    .catch(t.fail);
+  breaker.fire(0).then(_ => {
+    t.ok(timedOut, 'Breaker delayed execution on semaphore acquisition');
+    t.end();
+  }).catch(t.fail);
 });
 
 /**
@@ -823,10 +755,14 @@ function passFail (x) {
  * after 1 second.
  */
 function slowFunction () {
+  return timedFunction(10000);
+}
+
+function timedFunction (ms) {
   return new Promise((resolve, reject) => {
     const timer = setTimeout(() => {
       resolve('done');
-    }, 10000);
+    }, ms);
     if (typeof timer.unref === 'function') {
       timer.unref();
     }