refactor: split src into domain / application / infrastructure layers

Replace the history-driven lib/ + utils/ split with DDD layers:
- domain/: aggregate, repositories, value objects, pure parsers/format
- application/: feed-service, email-processor, feed-fetcher, stats
- infrastructure/: logging, auth, KV/R2 adapters, HTTP, framework glue

Pure file relocation; imports updated mechanically. Behaviour unchanged.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/infrastructure/unsubscribe.test.ts

@@ -0,0 +1,184 @@
+import { describe, it, expect } from "vitest";
+import { http, HttpResponse } from "msw";
+import { server, createMockEnv } from "../test/setup";
+import {
+  parseOneClickUnsubscribe,
+  sendOneClickUnsubscribe,
+  sendUnsubscribes,
+} from "./unsubscribe";
+import { getCounters } from "../application/stats";
+import type { Env } from "../types";
+
+const POST_HEADER = "List-Unsubscribe=One-Click";
+
+describe("parseOneClickUnsubscribe", () => {
+  it("returns the https URL when the one-click Post header is present", () => {
+    expect(
+      parseOneClickUnsubscribe({
+        "list-unsubscribe": "<https://news.example.com/u?t=abc>",
+        "list-unsubscribe-post": POST_HEADER,
+      }),
+    ).toBe("https://news.example.com/u?t=abc");
+  });
+
+  it("prefers the https URL when both https and mailto are present", () => {
+    expect(
+      parseOneClickUnsubscribe({
+        "list-unsubscribe":
+          "<mailto:unsub@example.com>, <https://example.com/u/1>",
+        "list-unsubscribe-post": POST_HEADER,
+      }),
+    ).toBe("https://example.com/u/1");
+  });
+
+  it("returns null for a mailto-only header", () => {
+    expect(
+      parseOneClickUnsubscribe({
+        "list-unsubscribe": "<mailto:unsub@example.com>",
+        "list-unsubscribe-post": POST_HEADER,
+      }),
+    ).toBeNull();
+  });
+
+  it("returns null when the Post header is missing", () => {
+    expect(
+      parseOneClickUnsubscribe({
+        "list-unsubscribe": "<https://example.com/u/1>",
+      }),
+    ).toBeNull();
+  });
+
+  it("returns null when the Post header has the wrong value", () => {
+    expect(
+      parseOneClickUnsubscribe({
+        "list-unsubscribe": "<https://example.com/u/1>",
+        "list-unsubscribe-post": "List-Unsubscribe=Something",
+      }),
+    ).toBeNull();
+  });
+
+  it("matches headers and Post value case-insensitively", () => {
+    expect(
+      parseOneClickUnsubscribe({
+        "List-Unsubscribe": "<https://example.com/u/1>",
+        "List-Unsubscribe-Post": "list-unsubscribe=ONE-CLICK",
+      }),
+    ).toBe("https://example.com/u/1");
+  });
+
+  it("ignores plaintext http URLs", () => {
+    expect(
+      parseOneClickUnsubscribe({
+        "list-unsubscribe": "<http://example.com/u/1>",
+        "list-unsubscribe-post": POST_HEADER,
+      }),
+    ).toBeNull();
+  });
+
+  it("returns null when there are no headers", () => {
+    expect(parseOneClickUnsubscribe({})).toBeNull();
+  });
+});
+
+describe("sendOneClickUnsubscribe", () => {
+  it("POSTs the one-click body and returns true on success", async () => {
+    let captured: { method: string; contentType: string; body: string } | null =
+      null;
+    server.use(
+      http.post("https://example.com/u/1", async ({ request }) => {
+        captured = {
+          method: request.method,
+          contentType: request.headers.get("content-type") ?? "",
+          body: await request.text(),
+        };
+        return HttpResponse.text("ok");
+      }),
+    );
+
+    const ok = await sendOneClickUnsubscribe("https://example.com/u/1");
+
+    expect(ok).toBe(true);
+    expect(captured).toEqual({
+      method: "POST",
+      contentType: "application/x-www-form-urlencoded",
+      body: POST_HEADER,
+    });
+  });
+
+  it("returns false on a non-ok response", async () => {
+    server.use(
+      http.post("https://example.com/u/1", () =>
+        HttpResponse.text("nope", { status: 404 }),
+      ),
+    );
+    expect(await sendOneClickUnsubscribe("https://example.com/u/1")).toBe(
+      false,
+    );
+  });
+
+  it("returns false (no throw) on a network error", async () => {
+    server.use(
+      http.post("https://example.com/u/1", () => HttpResponse.error()),
+    );
+    expect(await sendOneClickUnsubscribe("https://example.com/u/1")).toBe(
+      false,
+    );
+  });
+});
+
+describe("sendUnsubscribes", () => {
+  it("de-dupes URLs and bumps unsubscribes_sent by the success count", async () => {
+    const env = createMockEnv() as unknown as Env;
+    let hitsOne = 0;
+    let hitsTwo = 0;
+    server.use(
+      http.post("https://example.com/a", () => {
+        hitsOne += 1;
+        return HttpResponse.text("ok");
+      }),
+      http.post("https://example.com/b", () => {
+        hitsTwo += 1;
+        return HttpResponse.text("ok");
+      }),
+    );
+
+    await sendUnsubscribes(
+      [
+        "https://example.com/a",
+        "https://example.com/a",
+        "https://example.com/b",
+      ],
+      env,
+    );
+
+    expect(hitsOne).toBe(1);
+    expect(hitsTwo).toBe(1);
+    const counters = await getCounters(env.EMAIL_STORAGE);
+    expect(counters.unsubscribes_sent).toBe(2);
+  });
+
+  it("only counts successful requests", async () => {
+    const env = createMockEnv() as unknown as Env;
+    server.use(
+      http.post("https://example.com/ok", () => HttpResponse.text("ok")),
+      http.post("https://example.com/bad", () =>
+        HttpResponse.text("no", { status: 500 }),
+      ),
+    );
+
+    await sendUnsubscribes(
+      ["https://example.com/ok", "https://example.com/bad"],
+      env,
+    );
+
+    const counters = await getCounters(env.EMAIL_STORAGE);
+    expect(counters.unsubscribes_sent).toBe(1);
+  });
+
+  it("does nothing for an empty list", async () => {
+    const env = createMockEnv() as unknown as Env;
+    await sendUnsubscribes([], env);
+    const counters = await getCounters(env.EMAIL_STORAGE);
+    expect(counters.unsubscribes_sent).toBe(0);
+  });
+});