Add hosted synthetic control plane

services/api/tests/synthetic-control.test.ts

@@ -0,0 +1,69 @@
+import { describe, expect, it } from "bun:test";
+import { DEFAULT_SYNTHETIC_CONTROL_STATE } from "@islandflow/types";
+import {
+  buildSyntheticDerivedStatus,
+  createRollingSyntheticProfileHits,
+  getSyntheticBackendDisabledReason,
+  getSyntheticProfileHitCounts,
+  recordSyntheticProfileHit,
+  resolveSyntheticBackendMode
+} from "../src/synthetic-control";
+
+describe("synthetic control backend mode", () => {
+  it("detects synthetic, mixed, and live hosted modes", () => {
+    expect(resolveSyntheticBackendMode("synthetic", "synthetic")).toBe("synthetic");
+    expect(resolveSyntheticBackendMode("synthetic", "alpaca")).toBe("mixed");
+    expect(resolveSyntheticBackendMode("alpaca", "alpaca")).toBe("live");
+  });
+
+  it("provides a useful disabled reason for non-synthetic modes", () => {
+    expect(getSyntheticBackendDisabledReason("mixed")).toContain("both hosted ingest adapters");
+    expect(getSyntheticBackendDisabledReason("live")).toContain("not synthetic");
+  });
+});
+
+describe("synthetic control rolling status", () => {
+  it("tracks public-profile hits inside the rolling coverage window", () => {
+    const hits = createRollingSyntheticProfileHits();
+
+    recordSyntheticProfileHit(hits, {
+      primary_profile_id: "event_driven",
+      source_ts: 1_000
+    });
+    recordSyntheticProfileHit(hits, {
+      primary_profile_id: "event_driven",
+      source_ts: 60_000
+    });
+    recordSyntheticProfileHit(hits, {
+      primary_profile_id: "arbitrage",
+      source_ts: 70_000
+    });
+
+    expect(getSyntheticProfileHitCounts(hits, 11 * 60_000, 10)).toEqual({
+      institutional_directional: 0,
+      retail_whale: 0,
+      event_driven: 1,
+      vol_seller: 0,
+      arbitrage: 1,
+      hedge_reactive: 0
+    });
+  });
+
+  it("builds derived status from the shared session engine", () => {
+    const hits = createRollingSyntheticProfileHits();
+    recordSyntheticProfileHit(hits, {
+      primary_profile_id: "hedge_reactive",
+      source_ts: Date.parse("2026-01-14T18:00:00Z")
+    });
+
+    const derived = buildSyntheticDerivedStatus(
+      Date.parse("2026-01-14T18:05:00Z"),
+      DEFAULT_SYNTHETIC_CONTROL_STATE,
+      hits
+    );
+
+    expect(derived.coverage_window_minutes).toBe(20);
+    expect(derived.focus_symbols.length).toBeGreaterThan(0);
+    expect(derived.profile_hit_counts.hedge_reactive).toBe(1);
+  });
+});