tests: standardize MSW error simulation and reduce handler boilerplate

src/constants.ts

@@ -22,10 +22,11 @@ export const CONTACT_SUPPORT_TEAM_MESSAGE =
 export const DETAILED_UPGRADES_VIEW_ENABLED =
   import.meta.env.VITE_DETAILED_UPGRADES_VIEW_ENABLED === "true";
 export const IS_MSW_ENABLED = import.meta.env.VITE_MSW_ENABLED === "true";
-export const MSW_ENDPOINTS_TO_INTERCEPT =
-  (import.meta.env.VITE_MSW_ENDPOINTS_TO_INTERCEPT ?? "")
-    .split(",")
-    .filter(Boolean) ?? [];
+export const MSW_ENDPOINTS_TO_INTERCEPT = (
+  import.meta.env.VITE_MSW_ENDPOINTS_TO_INTERCEPT ?? ""
+)
+  .split(",")
+  .filter(Boolean);
 export const HOMEPAGE_PATH = ROUTES.overview.root();
 export const DEFAULT_ACCESS_GROUP_NAME = "global";
 export const BREAKPOINT_PX = {

src/tests/browser.ts

@@ -1,18 +1,11 @@
 import { API_URL, API_URL_OLD, MSW_ENDPOINTS_TO_INTERCEPT } from "@/constants";
 import type { RequestHandler } from "msw";
-import { http, HttpResponse, passthrough } from "msw";
+import { http, passthrough } from "msw";
 import { setupWorker } from "msw/browser";
 import fallbackHandlers from "./server/handlers";
 
 const handlers: RequestHandler[] = [
   http.all("*", ({ request }) => {
-    if (request.url.includes("sentry.is.canonical.com")) {
-      return passthrough();
-    }
-
-    return;
-  }),
-  http.all("*", async ({ request }) => {
     if (!request.url.includes(API_URL) && !request.url.includes(API_URL_OLD)) {
       return passthrough();
     }
@@ -30,9 +23,9 @@ const handlers: RequestHandler[] = [
 
   ...fallbackHandlers,
 
-  http.all("*", async ({ request }) => {
-    console.log("Request not handled:", request.url);
-    return new HttpResponse(null, { status: 404 });
+  http.all("*", ({ request }) => {
+    console.warn("MSW: No handler matched, passing through:", request.url);
+    return passthrough();
   }),
 ];
 

src/tests/server/handlers/_constants.ts

@@ -1,10 +1,44 @@
 import { HttpResponse } from "msw";
 
 export const ENDPOINT_STATUS_API_ERROR_MESSAGE = `The endpoint status is set to "error".`;
+
+const DEFAULT_ERROR_STATUS = 500;
+
+/**
+ * @deprecated Use {@link createEndpointStatusError} instead.
+ * Keeping for backward compatibility during migration.
+ */
 export const ENDPOINT_STATUS_API_ERROR = HttpResponse.json(
   {
     error: "EndpointStatusError",
     message: ENDPOINT_STATUS_API_ERROR_MESSAGE,
   },
-  { status: 500 },
+  { status: DEFAULT_ERROR_STATUS },
 );
+
+/**
+ * Creates a fresh JSON-body error response for endpoint-status-driven error
+ * simulation. Use this where tests assert on the parsed error body (e.g.
+ * package-profiles, ubuntu-pro, activities list).
+ *
+ * Prefer this over the static `ENDPOINT_STATUS_API_ERROR` constant because
+ * response objects should not be shared across handler invocations.
+ */
+export const createEndpointStatusError = (status = DEFAULT_ERROR_STATUS) =>
+  HttpResponse.json(
+    {
+      error: "EndpointStatusError",
+      message: ENDPOINT_STATUS_API_ERROR_MESSAGE,
+    },
+    { status },
+  );
+
+/**
+ * Creates a fresh null-body error response for endpoint-status-driven error
+ * simulation. Use this where the handler originally used
+ * `throw new HttpResponse(null, { status: 500 })`.
+ */
+export const createEndpointStatusNetworkError = (
+  status = DEFAULT_ERROR_STATUS,
+) => new HttpResponse(null, { status });
+

src/tests/server/handlers/_helpers.ts

@@ -3,6 +3,7 @@ import type { HttpHandler } from "msw";
 import { http, HttpResponse } from "msw";
 import { API_URL } from "@/constants";
 import { getEndpointStatus } from "@/tests/controllers/controller";
+import { createEndpointStatusNetworkError } from "./_constants";
 
 interface GeneratePaginatedResponseProps<D> {
   data: D[];
@@ -73,6 +74,19 @@ export const isAction = (request: Request, actionName: string | string[]) => {
     : actionName.includes(action);
 };
 
+/**
+ * Returns `true` when the global endpoint-status controller has a non-default
+ * status that applies to the given path.  Pass the handler's own path so that
+ * a targeted `setEndpointStatus({ status: "error", path: "/features" })` only
+ * affects the matching handler.
+ */
+export function shouldApplyEndpointStatus(path?: string): boolean {
+  const { status, path: statusPath } = getEndpointStatus();
+  if (status === "default") return false;
+  if (!statusPath) return true;
+  return !!path && statusPath.includes(path);
+}
+
 interface GenerateGetListEndpointParams<T> {
   readonly path: string;
   readonly response: T[];
@@ -82,37 +96,31 @@ export function generateGetListEndpoint<T>({
   path,
   response,
 }: GenerateGetListEndpointParams<T>): HttpHandler {
-  return http.get<never, never, ApiPaginatedResponse<T>>(
-    `${API_URL}${path}`,
-    () => {
-      const endpointStatus = getEndpointStatus();
+  return http.get(`${API_URL}${path}`, () => {
+    if (shouldApplyEndpointStatus(path)) {
+      const { status } = getEndpointStatus();
 
-      if (
-        !endpointStatus.path ||
-        (endpointStatus.path && endpointStatus.path === path)
-      ) {
-        if (endpointStatus.status === "error") {
-          throw new HttpResponse(null, { status: 500 });
-        }
-
-        if (endpointStatus.status === "empty") {
-          return HttpResponse.json({
-            results: [],
-            count: 0,
-            next: null,
-            previous: null,
-          });
-        }
+      if (status === "error") {
+        throw createEndpointStatusNetworkError();
       }
 
-      return HttpResponse.json({
-        results: response,
-        count: response.length,
-        next: null,
-        previous: null,
-      });
-    },
-  );
+      if (status === "empty") {
+        return HttpResponse.json({
+          results: [],
+          count: 0,
+          next: null,
+          previous: null,
+        });
+      }
+    }
+
+    return HttpResponse.json({
+      results: response,
+      count: response.length,
+      next: null,
+      previous: null,
+    });
+  });
 }
 
 export const parseArray = (paramValue: string | null): string[] => {

src/tests/server/handlers/accessGroup.ts

@@ -20,13 +20,6 @@ export default [
     return HttpResponse.json(accessGroups);
   }),
 
-  http.get(API_URL_OLD, ({ request }) => {
-    if (!isAction(request, "ChangeComputersAccessGroup")) {
-      return;
-    }
-
-    return HttpResponse.json({ success: true });
-  }),
 
   http.get(API_URL_OLD, ({ request }) => {
     if (

src/tests/server/handlers/activity.ts

@@ -1,15 +1,14 @@
 import { API_URL, API_URL_OLD } from "@/constants";
-import type { Activity, GetActivitiesParams } from "@/features/activities";
+import type { Activity } from "@/features/activities";
 import { getEndpointStatus } from "@/tests/controllers/controller";
 import {
   activities,
   activityTypes,
   INVALID_ACTIVITY_SEARCH_QUERY,
 } from "@/tests/mocks/activity";
-import type { ApiPaginatedResponse } from "@/types/api/ApiPaginatedResponse";
 import { http, HttpResponse } from "msw";
-import { ENDPOINT_STATUS_API_ERROR } from "./_constants";
-import { generatePaginatedResponse, isAction } from "./_helpers";
+import { createEndpointStatusError, createEndpointStatusNetworkError } from "./_constants";
+import { generatePaginatedResponse, isAction, shouldApplyEndpointStatus } from "./_helpers";
 
 const STATUS_QUERY_REGEX = /(?:^|\s)status:([^\s]+)/;
 const TYPE_QUERY_REGEX = /(?:^|\s)type:([^\s]+)/;
@@ -48,13 +47,14 @@ const parseActivitiesQuery = (
 };
 
 export default [
-  http.get<never, GetActivitiesParams, ApiPaginatedResponse<Activity>>(
+  http.get(
     `${API_URL}activities`,
     async ({ request }) => {
-      const endpointStatus = getEndpointStatus();
-
-      if (endpointStatus.status === "error") {
-        throw ENDPOINT_STATUS_API_ERROR;
+      if (shouldApplyEndpointStatus("activities")) {
+        const { status } = getEndpointStatus();
+        if (status === "error") {
+          throw createEndpointStatusError();
+        }
       }
 
       const url = new URL(request.url);
@@ -97,17 +97,15 @@ export default [
     },
   ),
 
-  http.get<{ id: string }, GetActivitiesParams, Activity>(
+  http.get(
     `${API_URL}activities/:id`,
     async ({ params: { id } }) => {
-      const endpointStatus = getEndpointStatus();
-
-      if (endpointStatus.status === "error") {
-        throw new HttpResponse(null, { status: 500 });
+      if (shouldApplyEndpointStatus("activities/:id")) {
+        throw createEndpointStatusNetworkError();
       }
 
       return HttpResponse.json<Activity>(
-        activities.find((activity) => activity.id === parseInt(id)) ?? {
+        activities.find((activity) => activity.id === parseInt(id as string)) ?? {
           activity_status: "succeeded",
           approval_time: null,
           children: [],
@@ -162,26 +160,22 @@ export default [
     ]);
   }),
 
-  http.post<never, { activity_ids: number[] }, number[]>(
+  http.post(
     `${API_URL}activities/revert`,
     async () => {
-      const endpointStatus = getEndpointStatus();
-
-      if (endpointStatus.status === "error") {
-        throw ENDPOINT_STATUS_API_ERROR;
+      if (shouldApplyEndpointStatus("activities/revert")) {
+        throw createEndpointStatusError();
       }
 
       return HttpResponse.json([activities[0].id, activities[1].id]);
     },
   ),
 
-  http.post<never, { activity_ids: number[] }, number[]>(
+  http.post(
     `${API_URL}activities/reapply`,
     async () => {
-      const endpointStatus = getEndpointStatus();
-
-      if (endpointStatus.status === "error") {
-        throw ENDPOINT_STATUS_API_ERROR;
+      if (shouldApplyEndpointStatus("activities/reapply")) {
+        throw createEndpointStatusError();
       }
 
       return HttpResponse.json([activities[0].id, activities[1].id]);

src/tests/server/handlers/aptSource.ts

@@ -2,9 +2,9 @@ import { API_URL, API_URL_OLD } from "@/constants";
 import type { APTSource, GetAPTSourcesParams } from "@/features/apt-sources";
 import { getEndpointStatus } from "@/tests/controllers/controller";
 import { aptSources } from "@/tests/mocks/apt-sources";
-import { isAction } from "@/tests/server/handlers/_helpers";
+import { isAction, shouldApplyEndpointStatus } from "@/tests/server/handlers/_helpers";
 import { http, HttpResponse } from "msw";
-import { ENDPOINT_STATUS_API_ERROR } from "./_constants";
+import { createEndpointStatusNetworkError } from "./_constants";
 
 export default [
   http.get<never, GetAPTSourcesParams, APTSource[]>(
@@ -19,15 +19,10 @@ export default [
   ),
 
   http.delete(`${API_URL}repository/apt-source/:sourceId`, () => {
-    const endpointStatus = getEndpointStatus();
-
-    if (
-      !endpointStatus.path ||
-      (endpointStatus.path &&
-        endpointStatus.path === "repository/apt-source/:sourceId")
-    ) {
-      if (endpointStatus.status === "error") {
-        throw HttpResponse.json(ENDPOINT_STATUS_API_ERROR, { status: 500 });
+    if (shouldApplyEndpointStatus("repository/apt-source/:sourceId")) {
+      const { status } = getEndpointStatus();
+      if (status === "error") {
+        throw createEndpointStatusNetworkError();
       }
     }
 

src/tests/server/handlers/distributions.ts

@@ -4,6 +4,7 @@ import { getEndpointStatus } from "@/tests/controllers/controller";
 import { distributions } from "@/tests/mocks/distributions";
 import { http, HttpResponse } from "msw";
 import { isAction } from "@/tests/server/handlers/_helpers";
+import { createEndpointStatusNetworkError } from "./_constants";
 
 export default [
   http.get<never, GetDistributionsParams, Distribution[]>(
@@ -16,7 +17,7 @@ export default [
       const endpointStatus = getEndpointStatus();
 
       if (endpointStatus.status === "error") {
-        throw new HttpResponse(null, { status: 500 });
+        throw createEndpointStatusNetworkError();
       }
 
       if (endpointStatus.status === "empty") {

src/tests/server/handlers/eventsLog.ts

@@ -2,7 +2,8 @@ import { API_URL } from "@/constants";
 import type { EventLog, GetEventsLogParams } from "@/features/events-log";
 import { getEndpointStatus } from "@/tests/controllers/controller";
 import { eventsLog } from "@/tests/mocks/eventsLog";
-import { generatePaginatedResponse } from "@/tests/server/handlers/_helpers";
+import { generatePaginatedResponse, shouldApplyEndpointStatus } from "@/tests/server/handlers/_helpers";
+import { createEndpointStatusNetworkError } from "./_constants";
 import type { ApiPaginatedResponse } from "@/types/api/ApiPaginatedResponse";
 import { http, HttpResponse } from "msw";
 
@@ -12,8 +13,8 @@ export default [
     async ({ request }) => {
       const endpointStatus = getEndpointStatus();
 
-      if (endpointStatus.status === "error") {
-        throw new HttpResponse(null, { status: 500 });
+      if (shouldApplyEndpointStatus("events") && endpointStatus.status === "error") {
+        throw createEndpointStatusNetworkError();
       }
 
       const url = new URL(request.url);

src/tests/server/handlers/features.ts

@@ -3,11 +3,11 @@ import { API_URL } from "@/constants";
 import { features } from "@/tests/mocks/features";
 import { getEndpointStatus } from "@/tests/controllers/controller";
 import type { Feature } from "@/types/Feature";
-import type { ApiPaginatedResponse } from "@/types/api/ApiPaginatedResponse";
 import { generatePaginatedResponse } from "@/tests/server/handlers/_helpers";
+import { createEndpointStatusNetworkError } from "./_constants";
 
 export default [
-  http.get<never, never, ApiPaginatedResponse<Feature>>(
+  http.get(
     `${API_URL}features`,
     () => {
       const endpointStatus = getEndpointStatus();
@@ -23,7 +23,7 @@ export default [
       }
 
       if (endpointStatus.status === "error") {
-        throw new HttpResponse(null, { status: 500 });
+        throw createEndpointStatusNetworkError();
       }
 
       return HttpResponse.json(