feat(common): adding getSession method

packages/auth-common/src/components/__tests__/getSession.test.ts

@@ -0,0 +1,25 @@
+import { type HeadersLike, getSession } from "..";
+
+describe("getSession", () => {
+	const clientId = "testClient";
+
+	it("should return empty string if no session is found", () => {
+		const headers: HeadersLike = {};
+		expect(getSession({ headers, clientId })).toBe("");
+	});
+
+	it("should extract session from cookie", () => {
+		const session = "some-session";
+		const headers: HeadersLike = {
+			cookie: `auth.${clientId}.session=${session};`,
+		};
+		expect(getSession({ headers, clientId })).toBe(session);
+	});
+
+	it("should return empty string if cookie does not contain the session", () => {
+		const headers: HeadersLike = {
+			cookie: "someOtherCookie=value;",
+		};
+		expect(getSession({ headers, clientId })).toBe("");
+	});
+});

packages/auth-common/src/components/getSession.ts

@@ -0,0 +1,31 @@
+import type { HeadersLike } from "./getToken";
+
+const getFromCookie = (headers: HeadersLike, clientId: string) => {
+	const cookie = headers?.cookie;
+	if (typeof cookie !== "string") {
+		return;
+	}
+	const re = new RegExp(`auth.${clientId}.session=(.+?)(?:;|$)`);
+	const match = cookie.match(re);
+	if (!match) {
+		return;
+	}
+	return match[1];
+};
+
+/**
+ * Get a Session Id from a request.
+ *
+ * @param headers An object containing the request headers, usually `req.headers`.
+ * @param clientId The client ID to use.
+ *
+ */
+type GetSessionProps = {
+	clientId: string;
+	headers: HeadersLike;
+};
+export const getSession = ({ headers, clientId }: GetSessionProps): string => {
+	const fromCookie = getFromCookie(headers, clientId);
+
+	return fromCookie || "";
+};

packages/auth-common/src/components/index.ts

@@ -3,3 +3,4 @@ export * from "./verifyToken";
 export * from "./pkce";
 export * from "./getToken";
 export * from "./isGranted";
+export * from "./getSession";