test: |Worker| add junk_mail_policy regression tests for issue #1084 (#1089)

Cover the junk-mail policy behavior fixed in #1085:
- none/neutral results for SPF/DKIM/DMARC are treated as the method
  being absent and do not trigger JUNK_MAIL_CHECK_LIST rejection
- explicit fail results are still rejected
- JUNK_MAIL_FORCE_PASS_LIST only accepts an explicit pass

Run with: node --test-isolation=none --test worker/src/email/junk_mail_policy.test.mjs

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -21,6 +21,10 @@
 - fix: |AI 提取| HTML-only 邮件在发送给 Workers AI 前会先压缩为可读文本，避免样式模板过长导致验证码位于 4000 字截断之后而无法识别
 - fix: |Frontend| 移动端 Header 增加页头内边距，避免标题、菜单按钮与屏幕边缘过近
 
+### Testing
+
+- test: |Worker| 新增 junk_mail_policy 回归测试（issue #1084）：覆盖 SPF/DKIM/DMARC 的 `none`/`neutral` 按认证方法不存在处理、明确 `fail` 仍被拒收，以及 `JUNK_MAIL_FORCE_PASS_LIST` 仅接受明确 `pass`
+
 ### Improvements
 
 - docs: |README| 新增完整日文 README，并在中文和英文 README 中添加日文导航链接

CHANGELOG_EN.md

@@ -21,6 +21,10 @@
 - fix: |AI Extract| Convert HTML-only mail bodies into compact readable text before sending them to Workers AI, preventing long templates from pushing verification codes past the 4000-character truncation window
 - fix: |Frontend| Add mobile Header page padding so the title and menu button no longer sit too close to the screen edge
 
+### Testing
+
+- test: |Worker| Add junk_mail_policy regression tests (issue #1084): `none`/`neutral` results for SPF/DKIM/DMARC are treated as the method being absent, explicit `fail` results are still rejected, and `JUNK_MAIL_FORCE_PASS_LIST` only accepts an explicit `pass`
+
 ### Improvements
 
 - docs: |README| Add a complete Japanese README and Japanese navigation links to the Chinese and English READMEs

worker/src/email/junk_mail_policy.test.mjs

@@ -0,0 +1,81 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import { isJunkMailByHeaders } from "./junk_mail_policy.ts";
+
+const authenticationResultsHeader = (results) => [{
+    key: "Authentication-Results",
+    value: `mx.example; ${results}`,
+}];
+
+test("issue #1084: dmarc=none does not reject an otherwise passing message", () => {
+    const headers = authenticationResultsHeader(
+        "spf=pass smtp.mailfrom=sender.example; " +
+        "dkim=pass header.d=sender.example; " +
+        "dmarc=none; arc=pass"
+    );
+
+    assert.equal(
+        isJunkMailByHeaders(
+            headers,
+            ["spf", "dkim", "dmarc"],
+            ["spf"],
+        ),
+        false,
+    );
+});
+
+for (const [method, result] of [
+    ["spf", "none"],
+    ["spf", "neutral"],
+    ["dkim", "none"],
+    ["dkim", "neutral"],
+    ["dmarc", "none"],
+    ["dmarc", "neutral"],
+]) {
+    test(`${method}=${result} is absent for JUNK_MAIL_CHECK_LIST`, () => {
+        assert.equal(
+            isJunkMailByHeaders(
+                authenticationResultsHeader(`${method}=${result}`),
+                [method],
+                [],
+            ),
+            false,
+        );
+    });
+}
+
+for (const method of ["spf", "dkim", "dmarc"]) {
+    test(`${method}=fail is junk when the method is checked`, () => {
+        assert.equal(
+            isJunkMailByHeaders(
+                authenticationResultsHeader(`${method}=fail`),
+                [method],
+                [],
+            ),
+            true,
+        );
+    });
+}
+
+test("JUNK_MAIL_FORCE_PASS_LIST requires an explicit pass result", () => {
+    for (const result of ["none", "neutral", "fail"]) {
+        assert.equal(
+            isJunkMailByHeaders(
+                authenticationResultsHeader(`spf=${result}`),
+                [],
+                ["spf"],
+            ),
+            true,
+        );
+    }
+
+    assert.equal(
+        isJunkMailByHeaders(
+            authenticationResultsHeader("spf=pass"),
+            [],
+            ["spf"],
+        ),
+        false,
+    );
+});