fix(port-check): make port check more resilient. Fixes #49

src/common/net.spec.ts

@@ -8,7 +8,7 @@ const expect = chai.expect;
 chai.use(chaiAsPromised);
 
 describe("Net", () => {
-  const port = 1234;
+  const port = 4567;
   const host = "0.0.0.0";
   const specialPort = process.platform.match("win") ? -1 : 80;
 
@@ -21,22 +21,14 @@ describe("Net", () => {
 
     context("when the port is available", () => {
       it("should return a fulfilled promise", () => {
-        expect(isPortAvailable(port, host)).to.eventually.be.fulfilled;
+        expect(isPortAvailable(port + 1, host)).to.eventually.be.fulfilled;
       });
     });
 
     context("when the port is unavailable", () => {
-      it("should return a rejected promise", done => {
-        createServer(port).then((server: { close(): any }) => {
-          isPortAvailable(port, host).then(
-            () => {
-              server.close();
-              done(new Error(`Port ${port} should not be available`));
-            },
-            (e: any) => {
-              done();
-            }
-          );
+      it("should return a rejected promise", () => {
+        createServer(port).then((_: { close(): any }) => {
+          expect(isPortAvailable(port, host)).to.eventually.be.rejected;
         });
       });
     });

src/common/net.ts

@@ -5,16 +5,31 @@
  */
 
 import * as net from "net";
+import { Promise as bluebird } from "bluebird";
 
-const isPortAvailable = (port: number, host: string): Promise<void> => {
+const isPortAvailable = (port: number, host: string): Promise<void> =>
+  Promise.resolve(bluebird.each([host, "127.0.0.1", "localhost", "0.0.0.0"], h =>
+    portCheck(port, h)
+  )
+    .then(() => Promise.resolve(undefined))
+    .catch(e => Promise.reject(e)));
+
+const portCheck = (port: number, host: string): Promise<void> => {
   return new Promise((resolve, reject) => {
-    const server: any = net.createServer()
+    const server: any = net
+      .createServer()
       .listen({ port, host, exclusive: true })
-      .on("error", (e: any) => (e.code === "EADDRINUSE" ? reject(new Error(`Port ${port} is unavailable`)) : reject(e)))
-      .on("listening", () => server.once("close", () => resolve()).close());
+      .on("error", (e: any) => {
+        if (e.code === "EADDRINUSE") {
+          reject(new Error(`Port ${port} is unavailable`))
+        } else {
+          reject(e);
+        }
+      })
+      .on("listening", () => {
+        server.once("close", () => resolve()).close();
+      });
   });
 };
 
-export {
-  isPortAvailable,
-};
+export { isPortAvailable, portCheck };

src/pact.ts

@@ -92,7 +92,7 @@ export class Pact {
   public setup(): Promise<void> {
     return isPortAvailable(this.opts.port, this.opts.host)
       // Need to wrap it this way until we remove q.Promise from pact-node
-      .then(() => new Promise<void>((resolve, reject) => this.server.start().then(() => resolve(), () => reject())));
+      .then(() => new Promise<void>((resolve, reject) => this.server.start().then(() => resolve(), (e: any) => reject(e))))
   }
 
   /**