Create link parser and formatter

src/parser/parser.test.ts

@@ -0,0 +1,82 @@
+import {
+  parseLink,
+  parsePermalink,
+  parseArgs,
+  verifiers,
+  discriminate,
+  toURI,
+} from "./parser";
+import { LinkDiscriminator } from "./types";
+
+const curriedDiscriminate = (id: string) =>
+  discriminate(id, verifiers, LinkDiscriminator.ParseFailed);
+
+it("types identifiers correctly", () => {
+  expect(curriedDiscriminate("@user:matrix.org")).toEqual(
+    LinkDiscriminator.UserId
+  );
+  expect(curriedDiscriminate("!room:matrix.org")).toEqual(
+    LinkDiscriminator.RoomId
+  );
+  expect(
+    curriedDiscriminate("!somewhere:example.org/$event:example.org")
+  ).toEqual(LinkDiscriminator.Permalink);
+  expect(curriedDiscriminate("+group:matrix.org")).toEqual(
+    LinkDiscriminator.GroupId
+  );
+  expect(curriedDiscriminate("#alias:matrix.org")).toEqual(
+    LinkDiscriminator.Alias
+  );
+});
+
+it("types garbadge as such", () => {
+  expect(curriedDiscriminate("sdfa;fdlkja")).toEqual(
+    LinkDiscriminator.ParseFailed
+  );
+  expect(curriedDiscriminate("$event$matrix.org")).toEqual(
+    LinkDiscriminator.ParseFailed
+  );
+  expect(curriedDiscriminate("/user:matrix.org")).toEqual(
+    LinkDiscriminator.ParseFailed
+  );
+});
+
+it("parses vias", () => {
+  expect(
+    parseArgs("via=example.org&via=alt.example.org")
+  ).toHaveProperty("vias", ["example.org", "alt.example.org"]);
+});
+
+it("parses sharer", () => {
+  expect(parseArgs("sharer=blah")).toHaveProperty("sharer", "blah");
+});
+
+it("parses random args", () => {
+  expect(parseArgs("via=qreqrqwer&banter=2342")).toHaveProperty(
+    "extras.banter",
+    ["2342"]
+  );
+});
+
+it("parses permalinks", () => {
+  expect(parsePermalink("!somewhere:example.org/$event:example.org")).toEqual({
+    roomKind: LinkDiscriminator.RoomId,
+    roomLink: "!somewhere:example.org",
+    eventId: "$event:example.org",
+  });
+});
+
+it("formats links correctly", () => {
+  const bigLink =
+    "!somewhere:example.org/$event:example.org?via=dfasdf&via=jfjafjaf&uselesstag=useless";
+  const host = "matrix.org";
+  const prefix = host + "/#/";
+  const parse = parseLink(bigLink);
+
+  switch (parse.kind) {
+    case LinkDiscriminator.ParseFailed:
+      fail("Parse failed");
+    default:
+      expect(toURI(host, parse)).toEqual(prefix + bigLink);
+  }
+});