refactor(core): message tracker abstraction and formatter plugin registry

tests/formatter-registry.test.ts

@@ -0,0 +1,89 @@
+import { describe, it, expect } from "bun:test";
+import { findFormatter } from "../server/lib/formatters/registry";
+import { formatEvent } from "../server/lib/formatters";
+import type { Route, WebhookEvent } from "../server/lib/types";
+
+const SUPPORTED_EVENTS = [
+  "push",
+  "pull_request",
+  "pull_request_review",
+  "pull_request_review_comment",
+  "issues",
+  "issue_comment",
+  "workflow_run",
+  "workflow_job",
+  "status",
+  "deployment",
+  "ping",
+  "release",
+  "create",
+  "delete",
+  "star",
+  "fork",
+  "check_run",
+  "check_suite",
+  "commit_comment",
+  "deployment_status",
+  "member",
+  "label",
+  "milestone",
+  "discussion",
+  "discussion_comment",
+  "repository",
+  "code_scanning_alert",
+  "dependabot_alert",
+  "custom",
+];
+
+function makeRoute(): Route {
+  return {
+    id: "r1",
+    name: "test",
+    enabled: true,
+    filters: [],
+    targets: [{ platform: "discord", channelId: "c1" }],
+  };
+}
+
+describe("findFormatter", () => {
+  it("maps every supported event type to a formatter", () => {
+    for (const event of SUPPORTED_EVENTS) {
+      const formatter = findFormatter(event);
+      expect(formatter, `missing formatter for ${event}`).toBeDefined();
+      expect(formatter!.events).toContain(event);
+    }
+  });
+
+  it("returns undefined for an unknown event type", () => {
+    expect(findFormatter("totally_unknown_event")).toBeUndefined();
+  });
+});
+
+describe("formatEvent", () => {
+  it("falls back to the generic formatter for an unknown event", () => {
+    const route = makeRoute();
+    const event: WebhookEvent = {
+      event: "totally_unknown_event",
+      payload: { action: "opened" },
+    };
+    const message = formatEvent(route, event);
+    expect(message).toBeDefined();
+    expect(typeof message.title).toBe("string");
+    expect(message.color).toBe(9147550);
+  });
+
+  it("routes a known event through its dedicated formatter", () => {
+    const route = makeRoute();
+    const event: WebhookEvent = {
+      event: "issues",
+      payload: {
+        action: "opened",
+        repository: { full_name: "acme/widget" },
+        issue: { number: 7, title: "Add feature" },
+        sender: { login: "alice" },
+      },
+    };
+    const message = formatEvent(route, event);
+    expect(message.title).toContain("acme/widget#7");
+  });
+});