Add: getUrlAddress

Author: ikepu-tp

src/lib/getUrlAddress.test.ts

@@ -0,0 +1,43 @@
+import { AddressInfo } from "net";
+import { getUrlAddress } from "./getUrlAddress";
+
+
+describe("getUrlAddress", () => {
+  describe("when null is passed", () => {
+    it("returns null", () => {
+      const url = getUrlAddress(null);
+      expect(url).toBeNull();
+    });
+  });
+
+  describe("when string is passed", () => {
+    it("returns null", () => {
+      const url = getUrlAddress("foobar");
+      expect(url).toBeNull();
+    });
+  });
+
+  describe("when IPv4 is passed", () => {
+    it("returns correct url", () => {
+      const address: AddressInfo = {
+        address: "0.0.0.0",
+        family: "IPv4",
+        port: 8888,
+      }
+      const url = getUrlAddress(address);
+      expect(url).toEqual(`http://${address.address}:${address.port}`);
+    });
+  });
+
+  describe("when IPv6 is passed", () => {
+    it("returns correct url", () => {
+      const address: AddressInfo = {
+        address: "::",
+        family: "IPv6",
+        port: 8888,
+      }
+      const url = getUrlAddress(address);
+      expect(url).toEqual(`http://[${address.address}]:${address.port}`);
+    });
+  });
+});

src/lib/getUrlAddress.ts

@@ -0,0 +1,10 @@
+import { AddressInfo } from "net";
+
+
+export const getUrlAddress = (address: string | AddressInfo | null) => {
+  if (!address || typeof address === "string") return null;
+
+  if (["IPv4", "IPv6"].indexOf(address.family) === -1) throw new Error("Unknown address family");
+
+  return `http://${address.family === "IPv4" ? address.address : `[${address.address}]`}:${address.port}`;
+}