fix: make health events emission consistent (#2570)

* fix health events emission

* fix bloom test flakiness due to bloom filter properties

packages/sdk/src/health_indicator/health_indicator.spec.ts

@@ -15,7 +15,6 @@ describe("HealthIndicator", () => {
     libp2p = mockLibp2p();
     events = mockEvents();
     healthIndicator = new HealthIndicator({ libp2p, events });
-    healthIndicator.start();
   });
 
   afterEach(() => {
@@ -28,6 +27,8 @@ describe("HealthIndicator", () => {
   });
 
   it("should transition to Unhealthy when no connections", async () => {
+    healthIndicator.start();
+
     // Only track transition, starting as healthy
     (healthIndicator as any).value = HealthStatus.SufficientlyHealthy;
 
@@ -49,6 +50,8 @@ describe("HealthIndicator", () => {
   });
 
   it("should transition to MinimallyHealthy with one compatible peer", async () => {
+    healthIndicator.start();
+
     const statusChangePromise = new Promise<HealthStatus>((resolve) => {
       events.addEventListener("waku:health", (e: CustomEvent<HealthStatus>) =>
         resolve(e.detail)
@@ -70,6 +73,8 @@ describe("HealthIndicator", () => {
   });
 
   it("should transition to SufficientlyHealthy with multiple compatible peers", async () => {
+    healthIndicator.start();
+
     const statusChangePromise = new Promise<HealthStatus>((resolve) => {
       events.addEventListener("waku:health", (e: CustomEvent<HealthStatus>) =>
         resolve(e.detail)
@@ -110,11 +115,124 @@ describe("HealthIndicator", () => {
     expect(removeEventSpy.firstCall.args[0]).to.equal("peer:identify");
     expect(removeEventSpy.secondCall.args[0]).to.equal("peer:disconnect");
   });
+
+  it("should reassess health immediately when peer disconnects", async () => {
+    const peer1 = mockPeer("1", [FilterCodecs.SUBSCRIBE, LightPushCodec]);
+    const peer2 = mockPeer("2", [FilterCodecs.SUBSCRIBE, LightPushCodec]);
+    const connection1 = mockConnection("1");
+    const connection2 = mockConnection("2");
+    const connections = [connection1, connection2];
+
+    const getConnectionsStub = sinon
+      .stub(libp2p, "getConnections")
+      .returns(connections);
+    const peerStoreStub = sinon.stub(libp2p.peerStore, "get");
+    peerStoreStub.withArgs(connection1.remotePeer).resolves(peer1);
+    peerStoreStub.withArgs(connection2.remotePeer).resolves(peer2);
+
+    const statusChangePromise = new Promise<HealthStatus>((resolve) => {
+      events.addEventListener("waku:health", (e: CustomEvent<HealthStatus>) =>
+        resolve(e.detail)
+      );
+    });
+
+    healthIndicator.start();
+
+    await statusChangePromise;
+    expect(healthIndicator.toValue()).to.equal(
+      HealthStatus.SufficientlyHealthy
+    );
+
+    const statusChangePromise2 = new Promise<HealthStatus>((resolve) => {
+      events.addEventListener("waku:health", (e: CustomEvent<HealthStatus>) =>
+        resolve(e.detail)
+      );
+    });
+
+    const remainingConnections = [connection1];
+    getConnectionsStub.returns(remainingConnections);
+
+    libp2p.dispatchEvent(new CustomEvent("peer:disconnect", { detail: "2" }));
+
+    const changedStatus = await statusChangePromise2;
+    expect(changedStatus).to.equal(HealthStatus.MinimallyHealthy);
+    expect(healthIndicator.toValue()).to.equal(HealthStatus.MinimallyHealthy);
+  });
+
+  it("should perform initial health assessment on start", async () => {
+    const peer = mockPeer("1", [FilterCodecs.SUBSCRIBE, LightPushCodec]);
+    const connections = [mockConnection("1")];
+    sinon.stub(libp2p, "getConnections").returns(connections);
+    sinon.stub(libp2p.peerStore, "get").resolves(peer);
+
+    const statusChangePromise = new Promise<HealthStatus>((resolve) => {
+      events.addEventListener("waku:health", (e: CustomEvent<HealthStatus>) =>
+        resolve(e.detail)
+      );
+    });
+
+    healthIndicator.start();
+
+    const changedStatus = await statusChangePromise;
+    expect(changedStatus).to.equal(HealthStatus.MinimallyHealthy);
+    expect(healthIndicator.toValue()).to.equal(HealthStatus.MinimallyHealthy);
+  });
+
+  it("should handle peer store errors gracefully", async function () {
+    this.timeout(5000);
+
+    // Start with a healthy state
+    (healthIndicator as any).value = HealthStatus.SufficientlyHealthy;
+
+    const connections = [mockConnection("1")];
+    sinon.stub(libp2p, "getConnections").returns(connections);
+    sinon.stub(libp2p.peerStore, "get").rejects(new Error("Peer not found"));
+
+    const statusChangePromise = new Promise<HealthStatus>((resolve) => {
+      events.addEventListener("waku:health", (e: CustomEvent<HealthStatus>) =>
+        resolve(e.detail)
+      );
+    });
+
+    healthIndicator.start();
+
+    const changedStatus = await statusChangePromise;
+    expect(changedStatus).to.equal(HealthStatus.Unhealthy);
+    expect(healthIndicator.toValue()).to.equal(HealthStatus.Unhealthy);
+  });
+
+  it("should handle mixed protocol support correctly", async () => {
+    // Start with a healthy state to ensure status change
+    (healthIndicator as any).value = HealthStatus.SufficientlyHealthy;
+
+    const peer1 = mockPeer("1", [FilterCodecs.SUBSCRIBE]);
+    const peer2 = mockPeer("2", [LightPushCodec]);
+    const connection1 = mockConnection("1");
+    const connection2 = mockConnection("2");
+    const connections = [connection1, connection2];
+
+    sinon.stub(libp2p, "getConnections").returns(connections);
+    const peerStoreStub = sinon.stub(libp2p.peerStore, "get");
+    peerStoreStub.withArgs(connection1.remotePeer).resolves(peer1);
+    peerStoreStub.withArgs(connection2.remotePeer).resolves(peer2);
+
+    const statusChangePromise = new Promise<HealthStatus>((resolve) => {
+      events.addEventListener("waku:health", (e: CustomEvent<HealthStatus>) =>
+        resolve(e.detail)
+      );
+    });
+
+    healthIndicator.start();
+
+    const changedStatus = await statusChangePromise;
+    expect(changedStatus).to.equal(HealthStatus.MinimallyHealthy);
+    expect(healthIndicator.toValue()).to.equal(HealthStatus.MinimallyHealthy);
+  });
 });
 
 function mockLibp2p(): Libp2p {
   const peerStore = {
-    get: (id: any) => Promise.resolve(mockPeer(id.toString(), []))
+    get: () => Promise.reject(new Error("Peer not found"))
   };
 
   const events = new EventTarget();

packages/sdk/src/health_indicator/health_indicator.ts

@@ -43,6 +43,8 @@ export class HealthIndicator implements IHealthIndicator {
       "peer:disconnect",
       this.onPeerDisconnected as PeerEvent<PeerId>
     );
+
+    void this.assessHealth();
   }
 
   public stop(): void {
@@ -64,40 +66,42 @@ export class HealthIndicator implements IHealthIndicator {
 
   private async onPeerDisconnected(_event: CustomEvent<PeerId>): Promise<void> {
     log.info(`onPeerDisconnected: received libp2p event`);
-
+    await this.assessHealth();
-    const connections = this.libp2p.getConnections();
-
-    // we handle only Unhealthy here and onPeerIdentify will cover other cases
-    if (connections.length > 0) {
-      log.info("onPeerDisconnected: has connections, ignoring");
-    }
-
-    log.info(
-      `onPeerDisconnected: node identified as ${HealthStatus.Unhealthy}`
-    );
-
-    this.updateAndDispatchHealthEvent(HealthStatus.Unhealthy);
   }
 
   private async onPeerIdentify(
     _event: CustomEvent<IdentifyResult>
   ): Promise<void> {
     log.info(`onPeerIdentify: received libp2p event`);
+    await this.assessHealth();
+  }
 
+  private async assessHealth(): Promise<void> {
     const connections = this.libp2p.getConnections();
 
+    if (connections.length === 0) {
+      log.info("assessHealth: no connections, setting to Unhealthy");
+      this.updateAndDispatchHealthEvent(HealthStatus.Unhealthy);
+      return;
+    }
+
     const peers = await Promise.all(
       connections.map(async (c) => {
         try {
           return await this.libp2p.peerStore.get(c.remotePeer);
         } catch (e) {
+          log.warn(
+            `assessHealth: failed to get peer ${c.remotePeer}, skipping`
+          );
           return null;
         }
       })
     );
+
     const filterPeers = peers.filter((p) =>
       p?.protocols.includes(FilterCodecs.SUBSCRIBE)
     ).length;
+
     const lightPushPeers = peers.filter((p) =>
       p?.protocols.includes(LightPushCodec)
     ).length;
@@ -111,12 +115,14 @@ export class HealthIndicator implements IHealthIndicator {
       newValue = HealthStatus.MinimallyHealthy;
     } else {
       log.error(
-        `onPeerIdentify: unexpected state, cannot identify health status of the node: Filter:${filterPeers}; LightPush:${lightPushPeers}`
+        `assessHealth: unexpected state, cannot identify health status of the node: Filter:${filterPeers}; LightPush:${lightPushPeers}`
       );
       newValue = this.value;
     }
 
-    log.info(`onPeerIdentify: node identified as ${newValue}`);
+    log.info(
+      `assessHealth: node identified as ${newValue} Filter:${filterPeers}; LightPush:${lightPushPeers}`
+    );
     this.updateAndDispatchHealthEvent(newValue);
   }
 

packages/sds/src/bloom_filter/bloom.spec.ts

@@ -92,7 +92,13 @@ describe("BloomFilter", () => {
     }
 
     const actualErrorRate = falsePositives / testSize;
-    expect(actualErrorRate).to.be.lessThan(bloomFilter.errorRate * 1.5);
+    const expectedErrorRate = bloomFilter.errorRate;
+    const zScore = 2;
+    const stdError = Math.sqrt(
+      (expectedErrorRate * (1 - expectedErrorRate)) / testSize
+    );
+    const upperBound = expectedErrorRate + zScore * stdError;
+    expect(actualErrorRate).to.be.lessThan(upperBound);
   });
 
   it("should never report false negatives", () => {
@@ -153,6 +159,12 @@ describe("BloomFilter with special patterns", () => {
     }
 
     const fpRate = falsePositives / testSize;
-    expect(fpRate).to.be.lessThan(bloomFilter.errorRate * 1.5);
+    const expectedErrorRate = bloomFilter.errorRate;
+    const zScore = 2;
+    const stdError = Math.sqrt(
+      (expectedErrorRate * (1 - expectedErrorRate)) / testSize
+    );
+    const upperBound = expectedErrorRate + zScore * stdError;
+    expect(fpRate).to.be.lessThan(upperBound);
   });
 });