Ensure correct port is used to connect to IDE server.

CHANGELOG.md

@@ -19,6 +19,8 @@
   preprocessor. This allows providing visualization with standard library
   functionalities or defining utilities that are shared between multiple
   visualizations.
+- [Ensure correct port is used to connect to IDE server.][1314]. This avoids collisions with other 
+  applications and allows multiple instances of the IDE to run in parallel.
 
 #### EnsoGL (rendering engine)
 
@@ -30,7 +32,7 @@ you can find their release notes
 
 [1209]: https://github.com/enso-org/ide/pull/1209
 [1291]: https://github.com/enso-org/ide/pull/1291
-
+[1314]: https://github.com/enso-org/ide/pull/1314
 <br/>
 
 # Enso 2.0.0-alpha.2 (2020-03-04)

src/js/lib/client/src/index.js

@@ -363,6 +363,7 @@ let hideInsteadOfQuit = false
 
 let server     = null
 let mainWindow = null
+let origin     = null
 
 async function main() {
     runBackend()
@@ -372,6 +373,8 @@ async function main() {
         serverCfg.dir      = root
         serverCfg.fallback = '/assets/index.html'
         server             = await Server.create(serverCfg)
+        const port         = server.port
+        origin             = `http://localhost:${port}`
     }
     mainWindow = createWindow()
     mainWindow.on("close", (evt) => {
@@ -382,11 +385,6 @@ async function main() {
    })
 }
 
-let port = Server.DEFAULT_PORT
-if      (server)    { port = server.port }
-else if (args.port) { port = args.port }
-let origin = `http://localhost:${port}`
-
 function urlParamsFromObject(obj) {
     let params = []
     for (let key in obj) {

src/js/lib/common/src/server.js

@@ -10,7 +10,7 @@ import * as portfinder    from 'portfinder'
 // === Port ===
 // ============
 
-export const DEFAULT_PORT = 8080
+const DEFAULT_PORT = 8080
 
 async function findPort(cfg) {
     if (!cfg.port) {