port.ts refactoring

Signed-off-by: Roman <ixrock@gmail.com>

src/main/index.ts

@@ -50,7 +50,6 @@ async function main() {
   try {
     proxyPort = await getFreePort()
   } catch (error) {
-    logger.error(error)
     await dialog.showErrorBox("Lens Error", "Could not find a free port for the cluster proxy")
     app.quit();
   }

src/main/port.ts

@@ -1,31 +1,20 @@
+import net, { AddressInfo } from "net"
 import logger from "./logger"
-import { createServer, AddressInfo } from "net"
 
-// todo: use https://github.com/http-party/node-portfinder ?
+// todo: check https://github.com/http-party/node-portfinder ?
 
-const getNextAvailablePort = () => {
-  logger.debug("getNextAvailablePort() start")
-  const server = createServer()
-  server.unref()
-  return new Promise<number>((resolve, reject) =>
-    server
-      .on('error', (error: any) => reject(error))
-      .on('listening', () => {
-        logger.debug("*** server listening event ***")
-        const _port = (server.address() as AddressInfo).port
-        server.close(() => resolve(_port))
-      })
-      .listen({host: "127.0.0.1", port: 0}))
-}
-
-export const getFreePort = async () => {
-  logger.debug("getFreePort() start")
-  let freePort: number = null
-  try {
-    freePort = await getNextAvailablePort()
-    logger.debug("got port : " + freePort)
-  } catch(error) {
-    throw("getNextAvailablePort() threw: '" + error + "'")
-  }
-  return freePort
+export async function getFreePort(): Promise<number> {
+  logger.debug("Lookup new free port..");
+  return new Promise((resolve, reject) => {
+    const server = net.createServer().unref().listen({ port: 0 });
+    server.on("listening", () => {
+      const port = (server.address() as AddressInfo).port
+      server.close(() => resolve(port));
+      logger.debug(`New port found: ${port}`);
+    });
+    server.on("error", error => {
+      logger.error(`Can't resolve new port: "${error}"`);
+      reject(error);
+    });
+  })
 }

src/main/port_spec.ts

@@ -1,6 +1,8 @@
 import { EventEmitter } from 'events'
 import { getFreePort } from "./port"
 
+let newPort = 0;
+
 jest.mock("net", () => {
   return {
     createServer() {
@@ -10,7 +12,10 @@ jest.mock("net", () => {
           return this
         })
         address = () => {
-          return { port: 12345 }
+          newPort = Math.round(Math.random() * 10000)
+          return {
+            port: newPort
+          }
         }
         unref = jest.fn()
         close = jest.fn(cb => cb())
@@ -21,6 +26,6 @@ jest.mock("net", () => {
 
 describe("getFreePort", () => {
   it("finds the next free port", async () => {
-    return expect(getFreePort()).resolves.toEqual(expect.any(Number))
+    return expect(getFreePort()).resolves.toEqual(newPort);
   })
 })