Add tests for queue; allow custom backoff

src/queue.js

@@ -29,7 +29,7 @@ class Queue {
     this.max = 0;
     this.avg = 0;
     this.retries = options.retries || 0;
-    this.backoff = 200;
+    this.backoff = typeof options.backoff == "number" ? options.backoff : 200;
     this.retryCounts = {};
     this.closed = false;
     this.finished = false;

src/test/queue.spec.ts

@@ -0,0 +1,74 @@
+import * as sinon from "sinon";
+import * as chai from "chai";
+
+chai.use(require("chai-as-promised"));
+const { expect } = chai;
+
+const Queue = require("../queue");
+
+const TEST_ERROR = new Error("foobar");
+
+describe("Queue", () => {
+  it("should handle tasks", () => {
+    const handler = sinon.stub().resolves();
+    const q = new Queue({
+      handler,
+    });
+
+    q.add(4);
+    q.close();
+    q.process();
+
+    return q.wait()
+      .then(() => {
+        expect(handler.callCount).to.equal(1);
+      });
+  });
+
+  it("should not retry", () => {
+    const handler = sinon.stub().rejects(TEST_ERROR);
+    const q = new Queue({
+      handler,
+      retries: 0,
+    });
+
+    q.add(4);
+    q.close();
+    q.process();
+
+    return q.wait()
+      .then(() => {
+        throw new Error("handler should have rejected");
+      })
+      .catch((err: Error) => {
+        expect(err).to.equal(TEST_ERROR);
+      })
+      .then(() => {
+        expect(handler.callCount).to.equal(1);
+      });
+  });
+
+  it("should retry the number of retries, plus one", () => {
+    const handler = sinon.stub().rejects(TEST_ERROR);
+    const q = new Queue({
+      backoff: 0,
+      handler,
+      retries: 3,
+    });
+
+    q.add(4);
+    q.close();
+    q.process();
+
+    return q.wait()
+      .then(() => {
+        throw new Error("handler should have rejected");
+      })
+      .catch((err: Error) => {
+        expect(err).to.equal(TEST_ERROR);
+      })
+      .then(() => {
+        expect(handler.callCount).to.equal(4);
+      });
+  });
+});