@serve-tools/polyfill-urlpattern

The @serve-tools/polyfill-urlpattern package installs the standard URLPattern constructor when it is missing and preserves an existing native implementation. Its fallback comes from @serve-tools/ponyfill-urlpattern.

import "@serve-tools/polyfill-urlpattern";

const pattern = new URLPattern({ pathname: "/books/:id" });

pattern.exec("https://example.com/books/42")?.pathname.groups.id; // "42"

Install

npm install @serve-tools/polyfill-urlpattern

Usage

Import the package before code that expects globalThis.URLPattern to exist. The installed global is writable, configurable, and non-enumerable, matching the native constructor's property descriptor. Native implementations are never replaced.

Import the ./URLPattern subpath to select the native constructor when available or the fallback otherwise without modifying the global environment:

import { URLPattern } from "@serve-tools/polyfill-urlpattern/URLPattern";

const pattern = new URLPattern("/books/:id", "https://example.com");

pattern.test("https://example.com/books/42"); // true

Import @serve-tools/polyfill-urlpattern/apply/URLPattern when global installation should use the explicit selective entrypoint.

Use @serve-tools/ponyfill-urlpattern instead when the fallback implementation or its exported URLPatternInput, URLPatternOptions, URLPatternInit, URLPatternResult, and URLPatternComponentResult types are needed directly.

Agent Skill

This package includes skills/serve-tools-polyfill-urlpattern/SKILL.md with version-aligned usage guidance for compatible coding agents. Activation is explicit; installing the package does not automatically trust or enable it.

Development

npm run typecheck --workspace @serve-tools/polyfill-urlpattern
npm test --workspace @serve-tools/polyfill-urlpattern
npm run build --workspace @serve-tools/polyfill-urlpattern
npm run check:package --workspace @serve-tools/polyfill-urlpattern

License

MIT-0