test(porting): differential tests against MoviePilot Rust-accelerated parsers

Snapshot differential tests (known deviations registered, current state passes):
- title/path recognition: 216 samples vs MP MetaInfo/MetaInfoPath
- filter rules: 42 rules x 28 torrents vs MP FilterModule
- RSS/indexer parsing: 15 feeds, 72 indexer samples
- zhconv: 69 samples
Generator: scripts/mp-sync/gen-differential.py; report: docs/porting/mp-rust-logic-parity.md

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/adapters/test/differential/diff-util.ts

@@ -0,0 +1,89 @@
+/**
+ * MP 差分测试共用工具:读取 scripts/mp-sync/gen-differential.py 生成的期望 JSON,登记偏差集合与实际偏差集合比对。
+ * 偏差 key:`<sampleId>.status` / `<sampleId>.count` / `<sampleId>#<行号>.<字段>`。
+ */
+import { readFileSync, writeFileSync } from "node:fs";
+import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+
+export const HERE = dirname(fileURLToPath(import.meta.url));
+
+export type DeviationKind = "intentional" | "missing" | "our_bug" | "mp_bug";
+export interface Deviation {
+  kind: DeviationKind;
+  note: string;
+  /** 仅在条件成立时才出现的偏差;local_tz_not_utc = 宿主本地时区偏移非 0 */
+  condition?: "local_tz_not_utc";
+}
+
+function conditionHolds(d: Deviation): boolean {
+  if (d.condition === "local_tz_not_utc") {
+    return new Date("2026-09-26T00:00:00").getTimezoneOffset() !== 0;
+  }
+  return true;
+}
+
+export interface DifferentialDoc<S> {
+  kind: string;
+  generatedFrom: Record<string, string>;
+  fields: string[];
+  samples: S[];
+  deviations: Record<string, Deviation>;
+}
+
+export function loadDoc<S>(name: string): DifferentialDoc<S> {
+  return JSON.parse(readFileSync(join(HERE, name), "utf8")) as DifferentialDoc<S>;
+}
+
+export function readInput(rel: string): string {
+  return readFileSync(join(HERE, rel), "utf8");
+}
+
+export interface Mismatch {
+  key: string;
+  mp: unknown;
+  ours: unknown;
+}
+
+/** null / undefined 视为同一"缺省";其余按 JSON 结构比较 */
+export function sameValue(a: unknown, b: unknown): boolean {
+  if (a == null && b == null) return true;
+  return JSON.stringify(a) === JSON.stringify(b);
+}
+
+export class FieldCollector {
+  readonly mismatches: Mismatch[] = [];
+  compared = 0;
+  equal = 0;
+  check(key: string, mp: unknown, ours: unknown): void {
+    this.compared++;
+    if (sameValue(mp, ours)) this.equal++;
+    else this.mismatches.push({ key, mp, ours });
+  }
+}
+
+/** 实际不一致集合 vs 登记集合:返回两个方向的差集(均为空才通过)。 */
+export function diffAgainstRegistry(
+  actual: Mismatch[],
+  registry: Record<string, Deviation>,
+): { unregistered: Mismatch[]; stale: string[] } {
+  const actualKeys = new Set(actual.map((m) => m.key));
+  return {
+    unregistered: actual.filter((m) => !(m.key in registry)),
+    stale: Object.entries(registry)
+      .filter(([k, d]) => !actualKeys.has(k) && conditionHolds(d))
+      .map(([k]) => k),
+  };
+}
+
+/** 设置环境变量 DIFF_DUMP_DIR 时把实际不一致写成 <name>.mismatches.json(整理 deviations 用) */
+export function dumpMismatches(name: string, ms: Mismatch[], stats?: { compared: number; equal: number }): void {
+  const dir = process.env.DIFF_DUMP_DIR;
+  if (dir) {
+    writeFileSync(join(dir, `${name}.mismatches.json`), `${JSON.stringify({ stats, mismatches: ms }, null, 2)}\n`);
+  }
+}
+
+export function formatMismatches(ms: Mismatch[]): string {
+  return ms.map((m) => `${m.key}\n    mp:   ${JSON.stringify(m.mp)}\n    ours: ${JSON.stringify(m.ours)}`).join("\n");
+}