From 9ffcdea312aa737e7d18a294ef0f449e512cdfd3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marc-Andr=C3=A9=20Bombeck?= <mbombeck@gmail.com>
Date: Tue, 20 Oct 2026 04:37:08 +0200
Subject: [PATCH] fix(insights): keep chronic conditions out of the symptom
 series fill

The symptom-severity series fills healthy days with zero across each
illness episode's span. A chronic condition has no end, so its span
covered the whole window and the correlation engine read a near-constant
run of zeros. Only episodes that can put the account into Rest Mode
(`REST_MODE_EPISODE_WHERE`) carry a span now.
---
 .../__tests__/symptom-series-chronic.test.ts  | 78 +++++++++++++++++++
 .../insights/correlation-channel-series.ts    | 11 ++-
 2 files changed, 86 insertions(+), 3 deletions(-)
 create mode 100644 src/lib/insights/__tests__/symptom-series-chronic.test.ts

diff --git a/src/lib/insights/__tests__/symptom-series-chronic.test.ts b/src/lib/insights/__tests__/symptom-series-chronic.test.ts
new file mode 100644
index 000000000..c949b3380
--- /dev/null
+++ b/src/lib/insights/__tests__/symptom-series-chronic.test.ts
@@ -0,0 +1,78 @@
+/**
+ * A chronic condition does not zero-fill the symptom-severity series.
+ *
+ * The series fills healthy days with 0 across an episode's span. A chronic
+ * condition has no end, so its span covered the whole window and the engine
+ * correlated a near-constant run of zeros. Only episodes that can put the
+ * account into Rest Mode carry a span; the fake store below honours the
+ * lifecycle filter the way Postgres would.
+ */
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+type Episode = {
+  id: string;
+  lifecycle: string;
+  onsetAt: Date;
+  resolvedAt: Date | null;
+};
+const store: { episodes: Episode[] } = { episodes: [] };
+
+vi.mock("@/lib/db", () => ({
+  prisma: {
+    illnessEpisode: {
+      findMany: vi.fn(
+        async (args: { where: { lifecycle?: { not: string } } }) =>
+          store.episodes.filter(
+            (e) =>
+              args.where.lifecycle === undefined ||
+              e.lifecycle !== args.where.lifecycle.not,
+          ),
+      ),
+    },
+    illnessDayLog: { findMany: vi.fn(async () => []) },
+  },
+}));
+
+import { fetchSymptomSeries } from "../correlation-channel-series";
+
+const DAY = 24 * 60 * 60 * 1000;
+const since = new Date(Date.now() - 60 * DAY);
+
+beforeEach(() => {
+  store.episodes = [];
+});
+
+describe("fetchSymptomSeries", () => {
+  it("has no series for a chronic condition alone", async () => {
+    store.episodes = [
+      {
+        id: "chronic",
+        lifecycle: "CHRONIC_ONGOING",
+        onsetAt: new Date(Date.now() - 900 * DAY),
+        resolvedAt: null,
+      },
+    ];
+    const series = await fetchSymptomSeries("user-1", "UTC", since);
+    expect(series.points).toEqual([]);
+  });
+
+  it("fills only the acute episode's span beside a chronic one", async () => {
+    store.episodes = [
+      {
+        id: "chronic",
+        lifecycle: "CHRONIC_ONGOING",
+        onsetAt: new Date(Date.now() - 900 * DAY),
+        resolvedAt: null,
+      },
+      {
+        id: "cold",
+        lifecycle: "ACUTE",
+        onsetAt: new Date(Date.now() - 20 * DAY),
+        resolvedAt: new Date(Date.now() - 14 * DAY),
+      },
+    ];
+    const series = await fetchSymptomSeries("user-1", "UTC", since);
+    expect(series.points.length).toBeGreaterThanOrEqual(6);
+    expect(series.points.length).toBeLessThanOrEqual(8);
+  });
+});
diff --git a/src/lib/insights/correlation-channel-series.ts b/src/lib/insights/correlation-channel-series.ts
index 57635b873..d383307fe 100644
--- a/src/lib/insights/correlation-channel-series.ts
+++ b/src/lib/insights/correlation-channel-series.ts
@@ -20,6 +20,7 @@
  * fabricating a constant.
  */
 import { prisma } from "@/lib/db";
+import { REST_MODE_EPISODE_WHERE } from "@/lib/illness/rest-mode";
 import {
   buildComplianceMedicationContext,
   COURSES_COMPLIANCE_SELECT,
@@ -152,9 +153,9 @@ export async function fetchComplianceSeries(
  * v1.21.0 (FDREXTEND) — build the user's SYMPTOM_SEVERITY daily series in the
  * `outcome` role (callers that need the behaviour role re-tag the returned
  * series — the points are role-invariant). Reads every in-window illness episode
- * + its day-logs; the builder zero-fills healthy days ONLY across real episode
- * spans, so a user with no episodes yields an empty series that degrades to
- * absent.
+ * that is not a chronic condition + its day-logs; the builder zero-fills healthy
+ * days ONLY across those spans, so a user with no such episode yields an empty
+ * series that degrades to absent.
  */
 export async function fetchSymptomSeries(
   userId: string,
@@ -165,11 +166,15 @@ export async function fetchSymptomSeries(
   const episodes = await prisma.illnessEpisode.findMany({
     // An episode overlaps the window when it onset before `now` and either is
     // ongoing or resolved at/after the window start.
+    // A chronic condition has no end, so its span would zero-fill every day
+    // of the window and hand the engine a near-constant series. Only the
+    // episodes that can put the account into Rest Mode carry a span.
     where: {
       userId,
       deletedAt: null,
       onsetAt: { lte: now },
       OR: [{ resolvedAt: null }, { resolvedAt: { gte: since } }],
+      ...REST_MODE_EPISODE_WHERE,
     },
     select: { id: true, onsetAt: true, resolvedAt: true },
   });