Add a new helper that detects network errors from the link chain (#12561)

* Inline type of network error in persisted-queries

* Remove NetworkError type in errors/index

* Add a NetworkError class

* Add tests for NetworkError

* Add tsdoc

* Add equality tester for NetworkError

* Export isErrorLike

* Leave cause as raw value in NetworkError

* Add a link that wraps errors with NetworkError

* Update exports snapshot

* Add changeset

* Rerun api report

* Update size limits

* Move isErrorLike to own file

* Update api report

* Update size limits

* Update doc

* Remove equality matcher

* Remove NetworkError from is tests

* Update NetworkError to be a facade object that registers errors

* Register network errors from the link chain

* Register errors from mutations

* Handle mutations

* Handle subscriptions

* Add watchQuery check

* Create separate internal function

* Update exports snapshot

* Remove network error link

* Update exports snapshot

* Update api report

* Update size limits

* Remove outdated file

* Export NetworkError in core

* Update changeset

* Add failing test case for mutations

* Wrap and register network error sooner in the chain

* Remove need to check CombinedGraphQLErrors

* Rename NetworkError to LinkError

* Add type to WeakSet

* Update changeset

* Rerun api report

* Update size limits

* Update exports snapshot

Author: jerelmiller

.api-reports/api-report-core.api.md

@@ -59,6 +59,7 @@ import { InMemoryCacheConfig } from '@apollo/client/cache';
 import type { InteropObservable } from 'rxjs';
 import { isReference } from '@apollo/client/utilities';
 import type { IsStrictlyAny } from '@apollo/client/utilities';
+import { LinkError } from '@apollo/client/errors';
 import { makeReference } from '@apollo/client/utilities';
 import { makeVar } from '@apollo/client/cache';
 import { Masked } from '@apollo/client/masking';
@@ -406,6 +407,8 @@ export function isNetworkRequestSettled(networkStatus?: NetworkStatus): boolean;
 
 export { isReference }
 
+export { LinkError }
+
 // @public (undocumented)
 class LocalState {
     // Warning: (ae-forgotten-export) The symbol "LocalStateOptions" needs to be exported by the entry point index.d.ts
@@ -1113,8 +1116,8 @@ export type WatchQueryOptions<TVariables extends OperationVariables = OperationV
 // src/core/ObservableQuery.ts:84:5 - (ae-forgotten-export) The symbol "NextFetchPolicyContext" needs to be exported by the entry point index.d.ts
 // src/core/ObservableQuery.ts:190:5 - (ae-forgotten-export) The symbol "QueryManager" needs to be exported by the entry point index.d.ts
 // src/core/ObservableQuery.ts:191:5 - (ae-forgotten-export) The symbol "QueryInfo" needs to be exported by the entry point index.d.ts
-// src/core/QueryManager.ts:186:5 - (ae-forgotten-export) The symbol "MutationStoreValue" needs to be exported by the entry point index.d.ts
-// src/core/QueryManager.ts:456:7 - (ae-forgotten-export) The symbol "UpdateQueries" needs to be exported by the entry point index.d.ts
+// src/core/QueryManager.ts:187:5 - (ae-forgotten-export) The symbol "MutationStoreValue" needs to be exported by the entry point index.d.ts
+// src/core/QueryManager.ts:455:7 - (ae-forgotten-export) The symbol "UpdateQueries" needs to be exported by the entry point index.d.ts
 // src/core/watchQueryOptions.ts:262:3 - (ae-forgotten-export) The symbol "IgnoreModifier" needs to be exported by the entry point index.d.ts
 
 // (No @packageDocumentation comment for this package)

.api-reports/api-report-errors.api.md

@@ -4,7 +4,7 @@
 
 ```ts
 
-import type { ErrorLike } from '@apollo/client';
+import { ErrorLike } from '@apollo/client';
 import type { FetchResult } from '@apollo/client/link/core';
 import type { FetchResult as FetchResult_2 } from '@apollo/client';
 import type { GraphQLFormattedError } from 'graphql';
@@ -62,12 +62,17 @@ type FetchResultWithSymbolExtensions<T> = FetchResult<T> & {
 // @public (undocumented)
 export function graphQLResultHasProtocolErrors<T>(result: FetchResult<T>): result is FetchResultWithSymbolExtensions<T>;
 
-// @public (undocumented)
-export type NetworkError = Error | ServerParseError | ServerError | null;
+// @public
+export const LinkError: {
+    is: (error: unknown) => boolean;
+};
 
 // @public (undocumented)
 export const PROTOCOL_ERRORS_SYMBOL: unique symbol;
 
+// @internal
+export function registerLinkError(error: ErrorLike): void;
+
 // @public
 export class ServerError extends Error {
     // Warning: (ae-forgotten-export) The symbol "ServerErrorOptions" needs to be exported by the entry point index.d.ts

.api-reports/api-report-link_persisted-queries.api.md

@@ -8,8 +8,9 @@ import { ApolloLink } from '@apollo/client/link/core';
 import type { DocumentNode } from 'graphql';
 import type { FormattedExecutionResult } from 'graphql';
 import type { GraphQLFormattedError } from 'graphql';
-import type { NetworkError } from '@apollo/client/errors';
 import type { Operation } from '@apollo/client/link/core';
+import type { ServerError } from '@apollo/client/errors';
+import type { ServerParseError } from '@apollo/client/errors';
 
 // @public (undocumented)
 interface BaseOptions {
@@ -49,7 +50,7 @@ export interface ErrorResponse {
     // (undocumented)
     meta: ErrorMeta;
     // (undocumented)
-    networkError?: NetworkError;
+    networkError?: Error | ServerParseError | ServerError | null;
     // (undocumented)
     operation: Operation;
     // (undocumented)

.api-reports/api-report-react.api.md

@@ -1609,8 +1609,8 @@ type WatchQueryOptions_2<TVariables extends OperationVariables_2 = OperationVari
 // src/core/ObservableQuery.ts:96:5 - (ae-forgotten-export) The symbol "RefetchWritePolicy" needs to be exported by the entry point index.d.ts
 // src/core/ObservableQuery.ts:190:5 - (ae-forgotten-export) The symbol "QueryManager" needs to be exported by the entry point index.d.ts
 // src/core/ObservableQuery.ts:191:5 - (ae-forgotten-export) The symbol "QueryInfo" needs to be exported by the entry point index.d.ts
-// src/core/QueryManager.ts:186:5 - (ae-forgotten-export) The symbol "MutationStoreValue" needs to be exported by the entry point index.d.ts
-// src/core/QueryManager.ts:456:7 - (ae-forgotten-export) The symbol "UpdateQueries" needs to be exported by the entry point index.d.ts
+// src/core/QueryManager.ts:187:5 - (ae-forgotten-export) The symbol "MutationStoreValue" needs to be exported by the entry point index.d.ts
+// src/core/QueryManager.ts:455:7 - (ae-forgotten-export) The symbol "UpdateQueries" needs to be exported by the entry point index.d.ts
 // src/core/types.ts:201:3 - (ae-forgotten-export) The symbol "MutationQueryReducer" needs to be exported by the entry point index.d.ts
 // src/core/types.ts:230:5 - (ae-forgotten-export) The symbol "Resolver" needs to be exported by the entry point index.d.ts
 // src/core/watchQueryOptions.ts:186:3 - (ae-forgotten-export) The symbol "UpdateQueryOptions" needs to be exported by the entry point index.d.ts

.api-reports/api-report.api.md

@@ -1294,6 +1294,11 @@ class Layer extends EntityStore {
     toObject(): NormalizedCacheObject;
 }
 
+// @public
+export const LinkError: {
+    is: (error: unknown) => boolean;
+};
+
 // @public (undocumented)
 class LocalState {
     // Warning: (ae-forgotten-export) The symbol "LocalStateOptions" needs to be exported by the entry point index.d.ts
@@ -2533,8 +2538,8 @@ interface WriteContext extends ReadMergeModifyContext {
 // src/core/ObservableQuery.ts:84:5 - (ae-forgotten-export) The symbol "NextFetchPolicyContext" needs to be exported by the entry point index.d.ts
 // src/core/ObservableQuery.ts:190:5 - (ae-forgotten-export) The symbol "QueryManager" needs to be exported by the entry point index.d.ts
 // src/core/ObservableQuery.ts:191:5 - (ae-forgotten-export) The symbol "QueryInfo" needs to be exported by the entry point index.d.ts
-// src/core/QueryManager.ts:186:5 - (ae-forgotten-export) The symbol "MutationStoreValue" needs to be exported by the entry point index.d.ts
-// src/core/QueryManager.ts:456:7 - (ae-forgotten-export) The symbol "UpdateQueries" needs to be exported by the entry point index.d.ts
+// src/core/QueryManager.ts:187:5 - (ae-forgotten-export) The symbol "MutationStoreValue" needs to be exported by the entry point index.d.ts
+// src/core/QueryManager.ts:455:7 - (ae-forgotten-export) The symbol "UpdateQueries" needs to be exported by the entry point index.d.ts
 // src/core/watchQueryOptions.ts:262:3 - (ae-forgotten-export) The symbol "IgnoreModifier" needs to be exported by the entry point index.d.ts
 // src/link/http/selectHttpOptionsAndBody.ts:128:1 - (ae-forgotten-export) The symbol "HttpQueryOptions" needs to be exported by the entry point index.d.ts
 

.changeset/odd-chicken-hide.md

@@ -0,0 +1,17 @@
+---
+"@apollo/client": minor
+---
+
+Add the ability to detect if an error was an error was emitted from the link chain. This is useful if your application throws custom errors in other areas of the application and you'd like to differentiate them from errors emitted by the link chain itself.
+
+To detect if an error was emitted from the link chain, use `LinkError.is`.
+
+```ts
+import { LinkError } from "@apollo/client";
+
+client.query({ query }).catch((error) => {
+  if (LinkError.is(error)) {
+    // This error originated from the link chain
+  }
+});
+```

.size-limits.json

@@ -1,6 +1,6 @@
 {
-  "import { ApolloClient, InMemoryCache, HttpLink } from \"@apollo/client\" (CJS)": 43269,
-  "import { ApolloClient, InMemoryCache, HttpLink } from \"@apollo/client\" (production) (CJS)": 38762,
-  "import { ApolloClient, InMemoryCache, HttpLink } from \"@apollo/client\"": 33223,
-  "import { ApolloClient, InMemoryCache, HttpLink } from \"@apollo/client\" (production)": 28027
+  "import { ApolloClient, InMemoryCache, HttpLink } from \"@apollo/client\" (CJS)": 43438,
+  "import { ApolloClient, InMemoryCache, HttpLink } from \"@apollo/client\" (production) (CJS)": 38878,
+  "import { ApolloClient, InMemoryCache, HttpLink } from \"@apollo/client\"": 33207,
+  "import { ApolloClient, InMemoryCache, HttpLink } from \"@apollo/client\" (production)": 28023
 }

src/__tests__/__snapshots__/exports.ts.snap

@@ -10,6 +10,7 @@ Array [
   "DocumentTransform",
   "HttpLink",
   "InMemoryCache",
+  "LinkError",
   "MissingFieldError",
   "NetworkStatus",
   "Observable",
@@ -77,6 +78,7 @@ Array [
   "DocumentTransform",
   "HttpLink",
   "InMemoryCache",
+  "LinkError",
   "MissingFieldError",
   "NetworkStatus",
   "Observable",
@@ -129,11 +131,13 @@ exports[`exports of public entry points @apollo/client/errors 1`] = `
 Array [
   "CombinedGraphQLErrors",
   "CombinedProtocolErrors",
+  "LinkError",
   "PROTOCOL_ERRORS_SYMBOL",
   "ServerError",
   "ServerParseError",
   "UnconventionalError",
   "graphQLResultHasProtocolErrors",
+  "registerLinkError",
   "toErrorLike",
 ]
 `;

src/core/QueryManager.ts

@@ -25,6 +25,7 @@ import { canonicalStringify } from "@apollo/client/cache";
 import {
   CombinedGraphQLErrors,
   graphQLResultHasProtocolErrors,
+  registerLinkError,
   toErrorLike,
 } from "@apollo/client/errors";
 import { PROTOCOL_ERRORS_SYMBOL } from "@apollo/client/errors";
@@ -411,9 +412,7 @@ export class QueryManager {
             }
           },
 
-          error: (err) => {
-            const error = toErrorLike(err);
-
+          error: (error) => {
             if (mutationStoreValue) {
               mutationStoreValue.loading = false;
               mutationStoreValue.error = error;
@@ -1100,7 +1099,7 @@ export class QueryManager {
             return of({ data: undefined } as SubscribeResult<TData>);
           }
 
-          return of({ data: undefined, error: toErrorLike(error) });
+          return of({ data: undefined, error });
         }),
         filter((result) => !!(result.data || result.error))
       );
@@ -1233,7 +1232,13 @@ export class QueryManager {
       );
     }
 
-    return observable;
+    return observable.pipe(
+      catchError((error) => {
+        error = toErrorLike(error);
+        registerLinkError(error);
+        throw error;
+      })
+    );
   }
 
   private getResultsFromLink<TData, TVariables extends OperationVariables>(
@@ -1307,8 +1312,6 @@ export class QueryManager {
         return aqr;
       }),
       catchError((error) => {
-        error = toErrorLike(error);
-
         // Avoid storing errors from older interrupted queries.
         if (requestId >= queryInfo.lastRequestId && errorPolicy === "none") {
           queryInfo.resetLastWrite();

src/core/index.ts

@@ -54,6 +54,7 @@ export type { FragmentMatcher, Resolver } from "./LocalState.js";
 export {
   CombinedGraphQLErrors,
   CombinedProtocolErrors,
+  LinkError,
   ServerError,
   ServerParseError,
   UnconventionalError,