Move providers from app to routes

src/node/routes/health.ts

@@ -0,0 +1,22 @@
+import { Heart } from "../heart"
+import { HttpProvider, HttpProviderOptions, HttpResponse } from "../http"
+
+/**
+ * Check the heartbeat.
+ */
+export class HealthHttpProvider extends HttpProvider {
+  public constructor(options: HttpProviderOptions, private readonly heart: Heart) {
+    super(options)
+  }
+
+  public async handleRequest(): Promise<HttpResponse> {
+    return {
+      cache: false,
+      mime: "application/json",
+      content: {
+        status: this.heart.alive() ? "alive" : "expired",
+        lastHeartbeat: this.heart.lastHeartbeat,
+      },
+    }
+  }
+}