Add cause field to ApolloError.

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

@@ -172,6 +172,10 @@ export interface ApolloClientOptions<TCacheShape> {
 export class ApolloError extends Error {
     // Warning: (ae-forgotten-export) The symbol "ApolloErrorOptions" needs to be exported by the entry point index.d.ts
     constructor({ graphQLErrors, protocolErrors, clientErrors, networkError, errorMessage, extraInfo, }: ApolloErrorOptions);
+    cause: ({
+        message: string;
+        extensions?: GraphQLErrorExtensions[];
+    } & Partial<Error>) | null;
     // (undocumented)
     clientErrors: ReadonlyArray<Error>;
     // (undocumented)

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

@@ -11,6 +11,10 @@ import type { GraphQLErrorExtensions } from 'graphql';
 // @public (undocumented)
 export class ApolloError extends Error {
     constructor({ graphQLErrors, protocolErrors, clientErrors, networkError, errorMessage, extraInfo, }: ApolloErrorOptions);
+    cause: ({
+        message: string;
+        extensions?: GraphQLErrorExtensions[];
+    } & Partial<Error>) | null;
     // (undocumented)
     clientErrors: ReadonlyArray<Error>;
     // (undocumented)

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

@@ -223,6 +223,10 @@ export interface ApolloContextValue {
 class ApolloError extends Error {
     // Warning: (ae-forgotten-export) The symbol "ApolloErrorOptions" needs to be exported by the entry point index.d.ts
     constructor({ graphQLErrors, protocolErrors, clientErrors, networkError, errorMessage, extraInfo, }: ApolloErrorOptions);
+    cause: ({
+        message: string;
+        extensions?: GraphQLErrorExtensions[];
+    } & Partial<Error>) | null;
     // (undocumented)
     clientErrors: ReadonlyArray<Error>;
     // (undocumented)

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

@@ -201,6 +201,10 @@ interface ApolloClientOptions<TCacheShape> {
 class ApolloError extends Error {
     // Warning: (ae-forgotten-export) The symbol "ApolloErrorOptions" needs to be exported by the entry point index.d.ts
     constructor({ graphQLErrors, protocolErrors, clientErrors, networkError, errorMessage, extraInfo, }: ApolloErrorOptions);
+    cause: ({
+        message: string;
+        extensions?: GraphQLErrorExtensions[];
+    } & Partial<Error>) | null;
     // (undocumented)
     clientErrors: ReadonlyArray<Error>;
     // (undocumented)

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

@@ -221,6 +221,10 @@ export interface ApolloContextValue {
 class ApolloError extends Error {
     // Warning: (ae-forgotten-export) The symbol "ApolloErrorOptions" needs to be exported by the entry point index.d.ts
     constructor({ graphQLErrors, protocolErrors, clientErrors, networkError, errorMessage, extraInfo, }: ApolloErrorOptions);
+    cause: ({
+        message: string;
+        extensions?: GraphQLErrorExtensions[];
+    } & Partial<Error>) | null;
     // (undocumented)
     clientErrors: ReadonlyArray<Error>;
     // (undocumented)

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

@@ -200,6 +200,10 @@ interface ApolloClientOptions<TCacheShape> {
 class ApolloError extends Error {
     // Warning: (ae-forgotten-export) The symbol "ApolloErrorOptions" needs to be exported by the entry point index.d.ts
     constructor({ graphQLErrors, protocolErrors, clientErrors, networkError, errorMessage, extraInfo, }: ApolloErrorOptions);
+    cause: ({
+        message: string;
+        extensions?: GraphQLErrorExtensions[];
+    } & Partial<Error>) | null;
     // (undocumented)
     clientErrors: ReadonlyArray<Error>;
     // (undocumented)

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

@@ -199,6 +199,10 @@ interface ApolloClientOptions<TCacheShape> {
 class ApolloError extends Error {
     // Warning: (ae-forgotten-export) The symbol "ApolloErrorOptions" needs to be exported by the entry point index.d.ts
     constructor({ graphQLErrors, protocolErrors, clientErrors, networkError, errorMessage, extraInfo, }: ApolloErrorOptions);
+    cause: ({
+        message: string;
+        extensions?: GraphQLErrorExtensions[];
+    } & Partial<Error>) | null;
     // (undocumented)
     clientErrors: ReadonlyArray<Error>;
     // (undocumented)

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

@@ -199,6 +199,10 @@ interface ApolloClientOptions<TCacheShape> {
 class ApolloError extends Error {
     // Warning: (ae-forgotten-export) The symbol "ApolloErrorOptions" needs to be exported by the entry point index.d.ts
     constructor({ graphQLErrors, protocolErrors, clientErrors, networkError, errorMessage, extraInfo, }: ApolloErrorOptions);
+    cause: ({
+        message: string;
+        extensions?: GraphQLErrorExtensions[];
+    } & Partial<Error>) | null;
     // (undocumented)
     clientErrors: ReadonlyArray<Error>;
     // (undocumented)

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

@@ -200,6 +200,10 @@ interface ApolloClientOptions<TCacheShape> {
 class ApolloError extends Error {
     // Warning: (ae-forgotten-export) The symbol "ApolloErrorOptions" needs to be exported by the entry point index.d.ts
     constructor({ graphQLErrors, protocolErrors, clientErrors, networkError, errorMessage, extraInfo, }: ApolloErrorOptions);
+    cause: ({
+        message: string;
+        extensions?: GraphQLErrorExtensions[];
+    } & Partial<Error>) | null;
     // (undocumented)
     clientErrors: ReadonlyArray<Error>;
     // (undocumented)

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

@@ -200,6 +200,10 @@ interface ApolloClientOptions<TCacheShape> {
 class ApolloError extends Error {
     // Warning: (ae-forgotten-export) The symbol "ApolloErrorOptions" needs to be exported by the entry point index.d.ts
     constructor({ graphQLErrors, protocolErrors, clientErrors, networkError, errorMessage, extraInfo, }: ApolloErrorOptions);
+    cause: ({
+        message: string;
+        extensions?: GraphQLErrorExtensions[];
+    } & Partial<Error>) | null;
     // (undocumented)
     clientErrors: ReadonlyArray<Error>;
     // (undocumented)

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

@@ -199,6 +199,10 @@ interface ApolloClientOptions<TCacheShape> {
 class ApolloError extends Error {
     // Warning: (ae-forgotten-export) The symbol "ApolloErrorOptions" needs to be exported by the entry point index.d.ts
     constructor({ graphQLErrors, protocolErrors, clientErrors, networkError, errorMessage, extraInfo, }: ApolloErrorOptions);
+    cause: ({
+        message: string;
+        extensions?: GraphQLErrorExtensions[];
+    } & Partial<Error>) | null;
     // (undocumented)
     clientErrors: ReadonlyArray<Error>;
     // (undocumented)

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

@@ -212,6 +212,10 @@ interface ApolloClientOptions<TCacheShape> {
 class ApolloError extends Error {
     // Warning: (ae-forgotten-export) The symbol "ApolloErrorOptions" needs to be exported by the entry point index.d.ts
     constructor({ graphQLErrors, protocolErrors, clientErrors, networkError, errorMessage, extraInfo, }: ApolloErrorOptions);
+    cause: ({
+        message: string;
+        extensions?: GraphQLErrorExtensions[];
+    } & Partial<Error>) | null;
     // (undocumented)
     clientErrors: ReadonlyArray<Error>;
     // (undocumented)

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

@@ -195,6 +195,10 @@ export interface ApolloContextValue {
 export class ApolloError extends Error {
     // Warning: (ae-forgotten-export) The symbol "ApolloErrorOptions" needs to be exported by the entry point index.d.ts
     constructor({ graphQLErrors, protocolErrors, clientErrors, networkError, errorMessage, extraInfo, }: ApolloErrorOptions);
+    cause: ({
+        message: string;
+        extensions?: GraphQLErrorExtensions[];
+    } & Partial<Error>) | null;
     // (undocumented)
     clientErrors: ReadonlyArray<Error>;
     // (undocumented)

.changeset/flat-onions-guess.md

@@ -0,0 +1,5 @@
+---
+"@apollo/client": patch
+---
+
+Add `cause` field to `ApolloError`.

.size-limits.json

@@ -1,4 +1,4 @@
 {
-  "dist/apollo-client.min.cjs": 39873,
-  "import { ApolloClient, InMemoryCache, HttpLink } from \"dist/index.js\" (production)": 32865
+  "dist/apollo-client.min.cjs": 39906,
+  "import { ApolloClient, InMemoryCache, HttpLink } from \"dist/index.js\" (production)": 32896
 }

src/errors/index.ts

@@ -81,6 +81,17 @@ export class ApolloError extends Error {
   }>;
   public clientErrors: ReadonlyArray<Error>;
   public networkError: Error | ServerParseError | ServerError | null;
+  /**
+   * Indicates the specific original cause of the error.
+   *
+   * This field contains the first available `networkError`, `graphQLError`, `protocolError`, `clientError`, or `null` if none are available.
+   */
+  public cause:
+    | ({
+        message: string;
+        extensions?: GraphQLErrorExtensions[];
+      } & Partial<Error>)
+    | null;
 
   // An object that can be used to provide some additional information
   // about an error, e.g. specifying the type of error this is. Used
@@ -106,6 +117,13 @@ export class ApolloError extends Error {
     this.networkError = networkError || null;
     this.message = errorMessage || generateErrorMessage(this);
     this.extraInfo = extraInfo;
+    this.cause =
+      [
+        networkError,
+        ...(graphQLErrors || []),
+        ...(protocolErrors || []),
+        ...(clientErrors || []),
+      ].find((e) => !!e) || null;
 
     // We're not using `Object.setPrototypeOf` here as it isn't fully
     // supported on Android (see issue #3236).