diff --git a/frontend/__tests__/entry_test.tsx b/frontend/__tests__/entry_test.tsx
index 244adabe5..3b06bc3c6 100644
--- a/frontend/__tests__/entry_test.tsx
+++ b/frontend/__tests__/entry_test.tsx
@@ -1,5 +1,4 @@
 jest.mock("../util/util", () => ({
-  shortRevision: jest.fn(() => "ABCD"),
   trim: jest.fn((s: unknown) => s),
   defensiveClone: jest.fn((s: unknown) => s)
 }));
@@ -13,7 +12,6 @@ jest.mock("i18next", () => ({ init: jest.fn() }));
 jest.mock("../routes", () => ({ attachAppToDom: { mock: "Yeah" } }));
 
 import { stopIE } from "../util/stop_ie";
-import { shortRevision } from "../util/util";
 import { detectLanguage } from "../i18n";
 import I from "i18next";
 
@@ -24,7 +22,6 @@ describe("entry file", () => {
     await import("../entry");
 
     expect(stopIE).toHaveBeenCalled();
-    expect(shortRevision).toHaveBeenCalled();
     expect(detectLanguage).toHaveBeenCalled();
     expect(I.init).toHaveBeenCalled();
     expect(console.log).toHaveBeenCalledWith("ABCD");
diff --git a/frontend/connectivity/ping_mqtt.tsx b/frontend/connectivity/ping_mqtt.tsx
index c7c5467fd..25279fbbd 100644
--- a/frontend/connectivity/ping_mqtt.tsx
+++ b/frontend/connectivity/ping_mqtt.tsx
@@ -41,7 +41,6 @@ export function sendOutboundPing(bot: Farmbot) {
   const no = () => markStale(id);
   dispatchQosStart(id);
   bot.ping().then(ok, no);
-  // setTimeout(no, PING_INTERVAL);
 }
 
 export function startPinging(bot: Farmbot) {
diff --git a/frontend/demo/__tests__/index_test.tsx b/frontend/demo/__tests__/index_test.tsx
index e4f244a2a..c4624d2ea 100644
--- a/frontend/demo/__tests__/index_test.tsx
+++ b/frontend/demo/__tests__/index_test.tsx
@@ -3,7 +3,6 @@ jest.mock("../../util/stop_ie", () => ({
 }));
 
 jest.mock("../../util", () => ({
-  shortRevision: jest.fn(),
   attachToRoot: jest.fn()
 }));
 
@@ -16,7 +15,7 @@ jest.mock("i18next", () => ({
 }));
 
 import { stopIE } from "../../util/stop_ie";
-import { shortRevision, attachToRoot } from "../../util";
+import { attachToRoot } from "../../util";
 import { detectLanguage } from "../../i18n";
 import { DemoIframe } from "../demo_iframe";
 import I from "i18next";
@@ -25,7 +24,6 @@ describe("DemoIframe loader", () => {
   it("calls  expected callbacks", (done) => {
     import("../index").then(() => {
       expect(stopIE).toHaveBeenCalled();
-      expect(shortRevision).toHaveBeenCalled();
       expect(detectLanguage).toHaveBeenCalled();
       expect(I.init).toHaveBeenCalled();
       expect(attachToRoot).toHaveBeenCalledWith(DemoIframe);
diff --git a/frontend/devices/connectivity/__tests__/qos_test.ts b/frontend/devices/connectivity/__tests__/qos_test.ts
index 66be8ea5c..63c144426 100644
--- a/frontend/devices/connectivity/__tests__/qos_test.ts
+++ b/frontend/devices/connectivity/__tests__/qos_test.ts
@@ -1,8 +1,17 @@
-import { calculateLatency, calculatePingLoss, completePing, startPing, failPing } from "../qos";
-import { fakePings } from "../../../__test_support__/fake_state/pings";
+import {
+  calculateLatency,
+  calculatePingLoss,
+  completePing,
+  startPing,
+  failPing,
+  PingDictionary
+} from "../qos";
+import {
+  fakePings
+} from "../../../__test_support__/fake_state/pings";
 
 describe("QoS helpers", () => {
-  it("calculateLatency", () => {
+  it("calculates latency", () => {
     const report = calculateLatency({
       "a": { kind: "timeout", start: 111, end: 423 },
       "b": { kind: "pending", start: 213 },
@@ -17,7 +26,15 @@ describe("QoS helpers", () => {
     expect(report.total).toEqual(4);
   });
 
-  it("calculatePingLoss", () => {
+  it("returns 0 when latency can't be calculated", () => {
+    const report = calculateLatency({});
+    expect(report.best).toEqual(0);
+    expect(report.worst).toEqual(0);
+    expect(report.average).toEqual(0);
+    expect(report.total).toEqual(1);
+  });
+
+  it("calculates ping loss", () => {
     const report = calculatePingLoss(fakePings());
     expect(report.total).toEqual(3);
     expect(report.complete).toEqual(1);
@@ -25,7 +42,7 @@ describe("QoS helpers", () => {
     expect(report.complete).toEqual(1);
   });
 
-  it("completePing", () => {
+  it("marks a ping as complete", () => {
     const KEY = "b";
     const state = fakePings();
     const before = state[KEY];
@@ -36,6 +53,14 @@ describe("QoS helpers", () => {
     expect(after && after.kind).toEqual("complete");
   });
 
+  it("does not mark pings as complete twice", () => {
+    const state: PingDictionary = {
+      "x": { kind: "complete", start: 319, end: 631 },
+    };
+    const nextState = completePing(state, "x");
+    expect(nextState).toBe(state); // No, not "toEqual"
+  });
+
   it("starts a ping", () => {
     const state = fakePings();
     const nextState = startPing(state, "x");
@@ -52,4 +77,11 @@ describe("QoS helpers", () => {
     expect(after && after.kind).toEqual("timeout");
   });
 
+  it("skips pings that don't need to be failed", () => {
+    const state: PingDictionary = {
+      "x": { kind: "complete", start: 319, end: 631 },
+    };
+    const nextState = failPing(state, "x");
+    expect(nextState).toBe(state); // No, not "toEqual"
+  });
 });