feat(web): hydrate dashboard tiles independently

apps/web/src/server/routes/dashboard.test.ts

@@ -1,11 +1,14 @@
-import { describe, expect, test } from "vitest";
+import { describe, expect, test, vi } from "vitest";
 import { dimensionLabDashboardFixture } from "$lib/dashboard-seed/dimensionlab";
-import { loadDashboardResponse } from "./dashboard";
+import { loadDashboardResponse, loadDashboardTileResponse } from "./dashboard";
 
 describe("dashboard API route", () => {
-  test("returns ready dashboard runtime state from the existing model loader", async () => {
+  test("returns the ready dashboard shell without hydrating live datasources", async () => {
+    const fetch = vi.spyOn(globalThis, "fetch").mockRejectedValue(
+      new Error("live datasource fetch should not run for the shell response"),
+    );
+
     const response = await loadDashboardResponse({
-      disableLiveDatasources: true,
       refreshSeedDocument: true,
       seedIfEmpty: true,
     });
@@ -15,5 +18,105 @@ describe("dashboard API route", () => {
     expect(response.document.metadata.title).toBe(
       dimensionLabDashboardFixture.metadata.title,
     );
+    expect(fetch).not.toHaveBeenCalled();
+
+    fetch.mockRestore();
+  });
+
+  test("reports when client-side live hydration is disabled", async () => {
+    const previous = process.env.DISABLE_LIVE_DATASOURCES;
+    process.env.DISABLE_LIVE_DATASOURCES = "1";
+
+    try {
+      const response = await loadDashboardResponse({
+        refreshSeedDocument: true,
+        seedIfEmpty: true,
+      });
+
+      expect(response.state).toBe("ready");
+      if (response.state !== "ready") throw new Error("expected ready dashboard");
+      expect(response.liveDatasourceHydration).toEqual({ enabled: false });
+    } finally {
+      if (previous === undefined) {
+        delete process.env.DISABLE_LIVE_DATASOURCES;
+      } else {
+        process.env.DISABLE_LIVE_DATASOURCES = previous;
+      }
+    }
+  });
+
+  test("hydrates a telemetry tile independently from the dashboard shell", async () => {
+    const fetch = vi.fn(async (input: RequestInfo | URL) => {
+      const url = String(input);
+
+      if (url.startsWith("https://prometheus.example/api/v1/query_range")) {
+        return jsonResponse({
+          status: "success",
+          data: {
+            result: [
+              {
+                metric: { host: "linux-infra" },
+                values: [
+                  [1771430000, "10"],
+                  [1771430060, "20"],
+                  [1771430120, "42"],
+                ],
+              },
+            ],
+          },
+        });
+      }
+
+      if (url.startsWith("https://prometheus.example/api/v1/query")) {
+        return jsonResponse({
+          status: "success",
+          data: {
+            result: [
+              {
+                metric: { host: "linux-infra" },
+                value: [1771430400, "42"],
+              },
+            ],
+          },
+        });
+      }
+
+      throw new Error(`Unhandled test request: ${url}`);
+    });
+
+    const response = await loadDashboardTileResponse(
+      { kind: "telemetry", id: "infra-ram" },
+      {
+        fetch,
+        prometheusBaseUrl: "https://prometheus.example",
+        refreshSeedDocument: true,
+        seedIfEmpty: true,
+      },
+    );
+
+    expect(response.state).toBe("ready");
+    if (response.state !== "ready") throw new Error("expected ready tile");
+    expect(response.tile).toEqual({ kind: "telemetry", id: "infra-ram" });
+    expect(response.item).toMatchObject({
+      id: "infra-ram",
+      value: { kind: "percent", value: 42 },
+      severity: "ok",
+      detail: "linux-infra",
+      sparkline: [10, 20, 42],
+    });
+    expect(fetch).toHaveBeenCalledWith(
+      expect.stringContaining("/api/v1/query?"),
+      expect.objectContaining({ cache: "no-store" }),
+    );
+    expect(fetch).toHaveBeenCalledWith(
+      expect.stringContaining("/api/v1/query_range?"),
+      expect.objectContaining({ cache: "no-store" }),
+    );
   });
 });
+
+function jsonResponse(payload: unknown): Response {
+  return new Response(JSON.stringify(payload), {
+    headers: { "content-type": "application/json" },
+  });
+}