refactor: remove get-port to allow reuse of the same port without min…

…imal wait time

core/package.json

@@ -36,7 +36,6 @@
     "exclusive-promises": "^1.0.3",
     "express": "^4.18.2",
     "fs-extra": "^11.1.1",
-    "get-port": "^7.0.0",
     "globby": "^13.2.0",
     "html-escaper": "^3.0.3",
     "http-terminator": "^3.2.0",

core/src/get-free-port.ts

@@ -0,0 +1,22 @@
+import net from "net";
+
+export async function getFreePort(min: number) {
+  for (let port = min; ; port++) {
+    if (await isAvailable(port)) {
+      return port;
+    }
+  }
+}
+
+async function isAvailable(port: number) {
+  return new Promise<boolean>((resolve) => {
+    const server = net.createServer();
+    server.unref();
+    server.on("error", () => resolve(false));
+    server.listen(port, () => {
+      server.close(() => {
+        resolve(true);
+      });
+    });
+  });
+}

core/src/index.ts

@@ -9,11 +9,11 @@ import { createTypeAnalyzer, UNKNOWN_TYPE } from "@previewjs/type-analyzer";
 import type { Reader } from "@previewjs/vfs";
 import express from "express";
 import fs from "fs-extra";
-import getPort, { portNumbers } from "get-port";
 import { createRequire } from "module";
 import path from "path";
 import type { Logger } from "pino";
 import { detectComponents } from "./detect-components";
+import { getFreePort } from "./get-free-port";
 import type { ComponentAnalysis, FrameworkPlugin } from "./plugins/framework";
 import type { SetupPreviewEnvironment } from "./preview-env";
 import { Previewer } from "./previewer";
@@ -205,12 +205,7 @@ export async function createWorkspace({
       start: async (allocatePort) => {
         const port = await previewer.start(async () => {
           const port = allocatePort ? await allocatePort() : 0;
-          return (
-            port ||
-            (await getPort({
-              port: portNumbers(3140, 4000),
-            }))
-          );
+          return port || (await getFreePort(3140));
         });
         return {
           url: () => `http://localhost:${port}`,