Extract helper functions from LoginPage

Change-Id: I507e223d0eff00bac3963d0b71f9bd648b9ab7b1

src/synapse/synapse.test.js

@@ -0,0 +1,31 @@
+import { isValidBaseUrl, splitMxid } from "./synapse";
+
+describe("splitMxid", () => {
+  it("splits valid MXIDs", () =>
+    expect(splitMxid("@name:domain.tld")).toEqual({
+      name: "name",
+      domain: "domain.tld",
+    }));
+  it("rejects invalid MXIDs", () => expect(splitMxid("foo")).toBeUndefined());
+});
+
+describe("isValidBaseUrl", () => {
+  it("accepts a http URL", () =>
+    expect(isValidBaseUrl("http://foo.bar")).toBeTruthy());
+  it("accepts a https URL", () =>
+    expect(isValidBaseUrl("https://foo.bar")).toBeTruthy());
+  it("accepts a valid URL with port", () =>
+    expect(isValidBaseUrl("https://foo.bar:1234")).toBeTruthy());
+  it("rejects undefined base URLs", () =>
+    expect(isValidBaseUrl(undefined)).toBeFalsy());
+  it("rejects null base URLs", () => expect(isValidBaseUrl(null)).toBeFalsy());
+  it("rejects empty base URLs", () => expect(isValidBaseUrl("")).toBeFalsy());
+  it("rejects non-string base URLs", () =>
+    expect(isValidBaseUrl({})).toBeFalsy());
+  it("rejects base URLs without protocol", () =>
+    expect(isValidBaseUrl("foo.bar")).toBeFalsy());
+  it("rejects base URLs with path", () =>
+    expect(isValidBaseUrl("http://foo.bar/path")).toBeFalsy());
+  it("rejects invalid base URLs", () =>
+    expect(isValidBaseUrl("http:/foo.bar")).toBeFalsy());
+});