chore: import upstream snapshot with attribution

tests/unit/ratelimitmanager-headers-split.test.ts

@@ -0,0 +1,107 @@
+/**
+ * Characterization + API-surface test: rateLimitManager.ts god-file decomposition.
+ *
+ * The pure rate-limit HEADER parsing block (STANDARD_HEADERS, ANTHROPIC_HEADERS,
+ * parseResetTime, toPlainHeaders) was extracted verbatim from
+ * open-sse/services/rateLimitManager.ts into the ZERO-IMPORT, self-contained
+ * leaf open-sse/services/rateLimitManager/headers.ts. The stateful limiter
+ * machinery (Bottleneck, watchdog timers, learned-limits Map) stays in the host.
+ *
+ * Verifies that:
+ *   1. parseResetTime / toPlainHeaders behave correctly (pure, DB/timer-free).
+ *   2. The host rateLimitManager.ts still exposes the FULL public API (17 names).
+ *   3. The headers leaf exports its pieces directly.
+ *
+ * The host import is released in a test.after hook (watchdog timers) so the
+ * native runner does not hang — mirrors the DB-handle teardown discipline.
+ */
+
+import test from "node:test";
+import assert from "node:assert/strict";
+
+import {
+  STANDARD_HEADERS,
+  ANTHROPIC_HEADERS,
+  parseResetTime,
+  toPlainHeaders,
+} from "../../open-sse/services/rateLimitManager/headers.ts";
+
+// ── 1. pure helpers ──────────────────────────────────────────────────────────
+
+test("rateLimitManager/headers — parseResetTime: nullish → null", () => {
+  assert.equal(parseResetTime(""), null);
+  assert.equal(parseResetTime(null), null);
+  assert.equal(parseResetTime("not-a-duration"), null);
+});
+
+test("rateLimitManager/headers — parseResetTime: duration strings → ms", () => {
+  assert.equal(parseResetTime("30s"), 30_000);
+  assert.equal(parseResetTime("500ms"), 500);
+  assert.equal(parseResetTime("1m30s"), 90_000);
+});
+
+test("rateLimitManager/headers — parseResetTime: bare number → seconds*1000", () => {
+  assert.equal(parseResetTime("5"), 5_000);
+});
+
+test("rateLimitManager/headers — toPlainHeaders normalizes to a string record", () => {
+  const out = toPlainHeaders({ "X-RateLimit-Remaining": "10", "Content-Type": "application/json" });
+  assert.equal(typeof out, "object");
+  assert.ok(out !== null && !Array.isArray(out));
+  // every value is a string
+  for (const v of Object.values(out)) assert.equal(typeof v, "string");
+});
+
+test("rateLimitManager/headers — STANDARD/ANTHROPIC header maps are objects with string fields", () => {
+  assert.equal(typeof STANDARD_HEADERS, "object");
+  assert.equal(typeof ANTHROPIC_HEADERS, "object");
+  assert.equal(typeof STANDARD_HEADERS.overLimit, "string");
+});
+
+// ── 2. host public API surface (17) ──────────────────────────────────────────
+
+const host = await import("../../open-sse/services/rateLimitManager.ts");
+
+test.after(async () => {
+  // release watchdog timers / limiter state so the runner exits cleanly
+  try {
+    await host.__resetRateLimitManagerForTests?.();
+  } catch {
+    /* ignore */
+  }
+  host.stopRateLimitWatchdog?.();
+});
+
+test("rateLimitManager.ts public API surface (17 names)", () => {
+  const expected = [
+    "__flushLearnedLimitsForTests",
+    "__getLimiterStateForTests",
+    "__resetRateLimitManagerForTests",
+    "applyRequestQueueSettings",
+    "disableRateLimitProtection",
+    "enableRateLimitProtection",
+    "getAllRateLimitStatus",
+    "getLearnedLimits",
+    "getRateLimitStatus",
+    "initializeRateLimits",
+    "isRateLimitEnabled",
+    "refreshConnectionRateLimits",
+    "startRateLimitWatchdog",
+    "stopRateLimitWatchdog",
+    "updateFromHeaders",
+    "updateFromResponseBody",
+    "withRateLimit",
+  ];
+  const missing = expected.filter((n) => typeof host[n] !== "function");
+  assert.deepEqual(missing, [], `missing public exports: ${missing.join(", ")}`);
+});
+
+// ── 3. leaf exports its pieces ───────────────────────────────────────────────
+
+test("headers.ts exports its helpers directly", async () => {
+  const h = await import("../../open-sse/services/rateLimitManager/headers.ts");
+  assert.equal(typeof h.parseResetTime, "function");
+  assert.equal(typeof h.toPlainHeaders, "function");
+  assert.equal(typeof h.STANDARD_HEADERS, "object");
+  assert.equal(typeof h.ANTHROPIC_HEADERS, "object");
+});