feat: add isValidHostname function (#774)

packages/protocol-http/jest.config.js

@@ -0,0 +1,5 @@
+const base = require("../../jest.config.base.js");
+
+module.exports = {
+  ...base
+};

packages/protocol-http/src/index.ts

@@ -1,3 +1,4 @@
 export * from "./httpResponse";
 export * from "./httpRequest";
 export * from "./httpHandler";
+export * from "./isValidHostname";

packages/protocol-http/src/isValidHostname.spec.ts

@@ -0,0 +1,11 @@
+import { isValidHostname } from "./isValidHostname";
+
+describe("implementation selection", () => {
+  it("should return true for valid hostnames", () => {
+    expect(isValidHostname("foo")).toBe(true);
+  });
+
+  it("should return false for invalid hostnames", () => {
+    expect(isValidHostname("foo.com/?bar")).toBe(false);
+  });
+});

packages/protocol-http/src/isValidHostname.ts

@@ -0,0 +1,4 @@
+export function isValidHostname(hostname: string): boolean {
+  const hostPattern = /^[a-zA-Z0-9]{1}$|^[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9]$/;
+  return hostPattern.test(hostname);
+}