chore(site): Add unit tests, mocks (#514)

* Extract and unit test redirect functions

* Move router to make app more testable

* Make mock entities more consistent

* Use labels instead of placeholders

* Fill out handlers

* Lint

* Reorganize App

* Make mock entities reference each other

* Add describes in tests

* Clean up api and mocks

site/src/util/redirect.test.ts

@@ -0,0 +1,20 @@
+import { embedRedirect, retrieveRedirect } from "./redirect"
+
+describe("redirect helper functions", () => {
+  describe("embedRedirect", () => {
+    it("embeds the page to return to in the URL", () => {
+      const result = embedRedirect("/workspaces", "/page")
+      expect(result).toEqual("/page?redirect=%2Fworkspaces")
+    })
+    it("defaults to navigating to the login page", () => {
+      const result = embedRedirect("/workspaces")
+      expect(result).toEqual("/login?redirect=%2Fworkspaces")
+    })
+  })
+  describe("retrieveRedirect", () => {
+    it("retrieves the page to return to from the URL", () => {
+      const result = retrieveRedirect("?redirect=%2Fworkspaces")
+      expect(result).toEqual("/workspaces")
+    })
+  })
+})

site/src/util/redirect.ts

@@ -0,0 +1,21 @@
+/**
+ * Creates a url containing a page to navigate to now, and embedding another
+ * URL in the query string so you can return to it later.
+ * @param navigateTo page to navigate to now (by default, /login)
+ * @param returnTo page to redirect to later (for instance, after logging in)
+ * @returns URL containing a redirect query parameter
+ */
+export const embedRedirect = (returnTo: string, navigateTo = "/login"): string =>
+  `${navigateTo}?redirect=${encodeURIComponent(returnTo)}`
+
+/**
+ * Retrieves a url from the query string of the current URL
+ * @param search the query string in the current URL
+ * @returns the URL to redirect to
+ */
+export const retrieveRedirect = (search: string): string => {
+  const defaultRedirect = "/"
+  const searchParams = new URLSearchParams(search)
+  const redirect = searchParams.get("redirect")
+  return redirect ? redirect : defaultRedirect
+}