refactor(discord): centralize target parsing

Co-authored-by: Jonathan Rhyne <jonathan@pspdfkit.com>

src/discord/targets.test.ts

@@ -0,0 +1,75 @@
+import { describe, expect, it } from "vitest";
+
+import { normalizeDiscordMessagingTarget } from "../channels/plugins/normalize-target.js";
+import { parseDiscordTarget, resolveDiscordChannelId } from "./targets.js";
+
+describe("parseDiscordTarget", () => {
+  it("parses user mention and prefixes", () => {
+    expect(parseDiscordTarget("<@123>")).toMatchObject({
+      kind: "user",
+      id: "123",
+      normalized: "user:123",
+    });
+    expect(parseDiscordTarget("<@!456>")).toMatchObject({
+      kind: "user",
+      id: "456",
+      normalized: "user:456",
+    });
+    expect(parseDiscordTarget("user:789")).toMatchObject({
+      kind: "user",
+      id: "789",
+      normalized: "user:789",
+    });
+    expect(parseDiscordTarget("discord:987")).toMatchObject({
+      kind: "user",
+      id: "987",
+      normalized: "user:987",
+    });
+  });
+
+  it("parses channel targets", () => {
+    expect(parseDiscordTarget("channel:555")).toMatchObject({
+      kind: "channel",
+      id: "555",
+      normalized: "channel:555",
+    });
+    expect(parseDiscordTarget("general")).toMatchObject({
+      kind: "channel",
+      id: "general",
+      normalized: "channel:general",
+    });
+  });
+
+  it("rejects ambiguous numeric ids without a default kind", () => {
+    expect(() => parseDiscordTarget("123")).toThrow(/Ambiguous Discord recipient/);
+  });
+
+  it("accepts numeric ids when a default kind is provided", () => {
+    expect(parseDiscordTarget("123", { defaultKind: "channel" })).toMatchObject({
+      kind: "channel",
+      id: "123",
+      normalized: "channel:123",
+    });
+  });
+
+  it("rejects non-numeric @ mentions", () => {
+    expect(() => parseDiscordTarget("@bob")).toThrow(/Discord DMs require a user id/);
+  });
+});
+
+describe("resolveDiscordChannelId", () => {
+  it("strips channel: prefix and accepts raw ids", () => {
+    expect(resolveDiscordChannelId("channel:123")).toBe("123");
+    expect(resolveDiscordChannelId("123")).toBe("123");
+  });
+
+  it("rejects user targets", () => {
+    expect(() => resolveDiscordChannelId("user:123")).toThrow(/channel id is required/i);
+  });
+});
+
+describe("normalizeDiscordMessagingTarget", () => {
+  it("defaults raw numeric ids to channels", () => {
+    expect(normalizeDiscordMessagingTarget("123")).toBe("channel:123");
+  });
+});