From f63d34d2c1c3c40e167631906eda7b3323614b28 Mon Sep 17 00:00:00 2001
From: Denver Coneybeare <dconeybe@google.com>
Date: Wed, 26 Feb 2025 13:34:27 -0500
Subject: [PATCH 01/16] Add API for partial errors

---
 packages/data-connect/src/api/index.ts  |  8 ++++
 packages/data-connect/src/core/error.ts | 62 ++++++++++++++++++++++---
 2 files changed, 64 insertions(+), 6 deletions(-)

diff --git a/packages/data-connect/src/api/index.ts b/packages/data-connect/src/api/index.ts
index 885dac5a923..71bd95557dc 100644
--- a/packages/data-connect/src/api/index.ts
+++ b/packages/data-connect/src/api/index.ts
@@ -22,3 +22,11 @@ export * from './Mutation';
 export * from './query';
 export { setLogLevel } from '../logger';
 export { validateArgs } from '../util/validateArgs';
+
+export { DataConnectError, DataConnectOperationError } from '../core/error';
+
+export type {
+  DataConnectErrorCode,
+  DataConnectOperationResponse,
+  DataConnectOperationErrorInfo
+} from '../core/error';
diff --git a/packages/data-connect/src/core/error.ts b/packages/data-connect/src/core/error.ts
index f0beb128afa..6aed2d4bb0f 100644
--- a/packages/data-connect/src/core/error.ts
+++ b/packages/data-connect/src/core/error.ts
@@ -40,8 +40,8 @@ export const Code = {
 
 /** An error returned by a DataConnect operation. */
 export class DataConnectError extends FirebaseError {
-  /** The stack of the error. */
-  readonly stack?: string;
+  /** The custom name for DataConnectError. */
+  readonly name: string = 'DataConnectError';
 
   /** @hideconstructor */
   constructor(
@@ -56,9 +56,59 @@ export class DataConnectError extends FirebaseError {
   ) {
     super(code, message);
 
-    // HACK: We write a toString property directly because Error is not a real
-    // class and so inheritance does not work correctly. We could alternatively
-    // do the same "back-door inheritance" trick that FirebaseError does.
-    this.toString = () => `${this.name}: [code=${this.code}]: ${this.message}`;
+    // Ensure the instanceof operator works as expected on subclasses of Error.
+    // See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error#custom_error_types
+    // and https://www.typescriptlang.org/docs/handbook/release-notes/typescript-2-2.html#support-for-newtarget
+    Object.setPrototypeOf(this, new.target.prototype);
   }
+
+  toString(): string {
+    return `${this.name}[code=${this.code}]: ${this.message}`;
+  }
+}
+
+/** An error returned by a DataConnect operation. */
+export class DataConnectOperationError extends DataConnectError {
+  /** The custom name for DataConnectOperationError. */
+  readonly name: string = 'DataConnectOperationError';
+
+  /** The response received from the backend. */
+  readonly response: DataConnectOperationResponse;
+
+  /** @hideconstructor */
+  constructor(message: string, response: DataConnectOperationResponse) {
+    super('partial-error', message);
+    this.response = response;
+
+    // Ensure the instanceof operator works as expected on subclasses of Error.
+    // See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error#custom_error_types
+    // and https://www.typescriptlang.org/docs/handbook/release-notes/typescript-2-2.html#support-for-newtarget
+    Object.setPrototypeOf(this, new.target.prototype);
+  }
+}
+
+export interface DataConnectOperationResponse {
+  // The "data" provided by the backend in the response message.
+  //
+  // Will be `undefined` if no "data" was provided in the response message.
+  // Otherwise, will be `null` if `null` was explicitly specified as the "data"
+  // in the response message. Otherwise, will be the value of the "data"
+  // specified as the "data" in the response message
+  readonly data?: Record<string, unknown> | null;
+
+  // The list of errors provided by the backend in the response message.
+  readonly errors: DataConnectOperationErrorInfo[];
+}
+
+// Information about the error, as provided in the response from the backend.
+// See https://spec.graphql.org/draft/#sec-Errors
+export interface DataConnectOperationErrorInfo {
+  // The error message.
+  readonly message: string;
+
+  // The path of the field in the response data to which this error relates.
+  // String values in this array refer to field names. Numeric values in this
+  // array always satisfy `Number.isInteger()` and refer to the index in an
+  // array.
+  readonly path: Array<string | number>;
 }

From 6032daff7f2a52af3cca234344a85555cfddb96b Mon Sep 17 00:00:00 2001
From: dconeybe <dconeybe@users.noreply.github.com>
Date: Wed, 26 Feb 2025 18:43:58 +0000
Subject: [PATCH 02/16] Update API reports

---
 common/api-review/data-connect.api.md | 38 +++++++++++++++++++++++++--
 1 file changed, 36 insertions(+), 2 deletions(-)

diff --git a/common/api-review/data-connect.api.md b/common/api-review/data-connect.api.md
index 1a698c229b4..833a988bfb9 100644
--- a/common/api-review/data-connect.api.md
+++ b/common/api-review/data-connect.api.md
@@ -52,6 +52,40 @@ export class DataConnect {
     setInitialized(): void;
 }
 
+// @public
+export class DataConnectError extends FirebaseError {
+    readonly code: DataConnectErrorCode;
+    readonly message: string;
+    readonly name: string;
+    // (undocumented)
+    toString(): string;
+}
+
+// @public (undocumented)
+export type DataConnectErrorCode = 'other' | 'already-initialized' | 'not-initialized' | 'not-supported' | 'invalid-argument' | 'partial-error' | 'unauthorized';
+
+// @public
+export class DataConnectOperationError extends DataConnectError {
+    readonly name: string;
+    readonly response: DataConnectOperationResponse;
+}
+
+// @public (undocumented)
+export interface DataConnectOperationErrorInfo {
+    // (undocumented)
+    readonly message: string;
+    // (undocumented)
+    readonly path: Array<string | number>;
+}
+
+// @public (undocumented)
+export interface DataConnectOperationResponse {
+    // (undocumented)
+    readonly data?: Record<string, unknown> | null;
+    // (undocumented)
+    readonly errors: DataConnectOperationErrorInfo[];
+}
+
 // @public
 export interface DataConnectOptions extends ConnectorConfig {
     // (undocumented)
@@ -67,7 +101,7 @@ export interface DataConnectResult<Data, Variables> extends OpResult<Data> {
 // @public
 export interface DataConnectSubscription<Data, Variables> {
     // (undocumented)
-    errCallback?: (e?: FirebaseError) => void;
+    errCallback?: (e?: DataConnectError) => void;
     // (undocumented)
     unsubscribe: () => void;
     // (undocumented)
@@ -118,7 +152,7 @@ export interface MutationResult<Data, Variables> extends DataConnectResult<Data,
 export type OnCompleteSubscription = () => void;
 
 // @public
-export type OnErrorSubscription = (err?: FirebaseError) => void;
+export type OnErrorSubscription = (err?: DataConnectError) => void;
 
 // @public
 export type OnResultSubscription<Data, Variables> = (res: QueryResult<Data, Variables>) => void;

From c5d38292bf7ba4798aa3dd37ba7fa28c38825557 Mon Sep 17 00:00:00 2001
From: Denver Coneybeare <dconeybe@google.com>
Date: Wed, 26 Feb 2025 13:58:53 -0500
Subject: [PATCH 03/16] src/core/error.ts: cleanups

---
 packages/data-connect/src/core/error.ts | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/packages/data-connect/src/core/error.ts b/packages/data-connect/src/core/error.ts
index 6aed2d4bb0f..3c817f616c3 100644
--- a/packages/data-connect/src/core/error.ts
+++ b/packages/data-connect/src/core/error.ts
@@ -40,7 +40,7 @@ export const Code = {
 
 /** An error returned by a DataConnect operation. */
 export class DataConnectError extends FirebaseError {
-  /** The custom name for DataConnectError. */
+  /** @internal */
   readonly name: string = 'DataConnectError';
 
   /** @hideconstructor */
@@ -52,7 +52,7 @@ export class DataConnectError extends FirebaseError {
     /**
      * A custom error description.
      */
-    readonly message: string
+    message: string
   ) {
     super(code, message);
 
@@ -62,6 +62,7 @@ export class DataConnectError extends FirebaseError {
     Object.setPrototypeOf(this, new.target.prototype);
   }
 
+  /** @internal */
   toString(): string {
     return `${this.name}[code=${this.code}]: ${this.message}`;
   }
@@ -69,7 +70,7 @@ export class DataConnectError extends FirebaseError {
 
 /** An error returned by a DataConnect operation. */
 export class DataConnectOperationError extends DataConnectError {
-  /** The custom name for DataConnectOperationError. */
+  /** @internal */
   readonly name: string = 'DataConnectOperationError';
 
   /** The response received from the backend. */

From 8a33180826a6ac273ff19424a6c05a3c899173d8 Mon Sep 17 00:00:00 2001
From: Denver Coneybeare <dconeybe@google.com>
Date: Wed, 26 Feb 2025 14:00:27 -0500
Subject: [PATCH 04/16] data-connect.api.md: updated

---
 common/api-review/data-connect.api.md | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/common/api-review/data-connect.api.md b/common/api-review/data-connect.api.md
index 833a988bfb9..1b93be0e9c3 100644
--- a/common/api-review/data-connect.api.md
+++ b/common/api-review/data-connect.api.md
@@ -55,10 +55,6 @@ export class DataConnect {
 // @public
 export class DataConnectError extends FirebaseError {
     readonly code: DataConnectErrorCode;
-    readonly message: string;
-    readonly name: string;
-    // (undocumented)
-    toString(): string;
 }
 
 // @public (undocumented)
@@ -66,7 +62,7 @@ export type DataConnectErrorCode = 'other' | 'already-initialized' | 'not-initia
 
 // @public
 export class DataConnectOperationError extends DataConnectError {
-    readonly name: string;
+    /* Excluded from this release type: name */
     readonly response: DataConnectOperationResponse;
 }
 

From 9f535fba730e89d30a6cb0d3a11252e913e77fa7 Mon Sep 17 00:00:00 2001
From: Maneesh Tewani <mtewani@google.com>
Date: Fri, 28 Feb 2025 15:34:36 -0800
Subject: [PATCH 05/16] Implemented partial error

---
 packages/data-connect/src/network/fetch.ts    | 18 ++++++++--
 packages/data-connect/test/unit/fetch.test.ts | 36 ++++++++++++++++++-
 2 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/packages/data-connect/src/network/fetch.ts b/packages/data-connect/src/network/fetch.ts
index 166422ca14c..eb1d22b6a3f 100644
--- a/packages/data-connect/src/network/fetch.ts
+++ b/packages/data-connect/src/network/fetch.ts
@@ -15,7 +15,12 @@
  * limitations under the License.
  */
 
-import { Code, DataConnectError } from '../core/error';
+import {
+  Code,
+  DataConnectError,
+  DataConnectOperationError,
+  DataConnectOperationResponse
+} from '../core/error';
 import { SDK_VERSION } from '../core/version';
 import { logDebug, logError } from '../logger';
 
@@ -106,10 +111,17 @@ export function dcFetch<T, U>(
       return jsonResponse;
     })
     .then(res => {
+      console.log(res.errors);
       if (res.errors && res.errors.length) {
         const stringified = JSON.stringify(res.errors);
-        logError('DataConnect error while performing request: ' + stringified);
-        throw new DataConnectError(Code.OTHER, stringified);
+        const response: DataConnectOperationResponse = {
+          errors: res.errors,
+          data: res.data
+        };
+        throw new DataConnectOperationError(
+          'DataConnect error while performing request: ' + stringified,
+          response
+        );
       }
       return res;
     });
diff --git a/packages/data-connect/test/unit/fetch.test.ts b/packages/data-connect/test/unit/fetch.test.ts
index 599260f8b10..688886934d7 100644
--- a/packages/data-connect/test/unit/fetch.test.ts
+++ b/packages/data-connect/test/unit/fetch.test.ts
@@ -34,7 +34,7 @@ function mockFetch(json: object, reject: boolean): sinon.SinonStub {
   initializeFetch(fakeFetchImpl);
   return fakeFetchImpl;
 }
-describe('fetch', () => {
+describe.only('fetch', () => {
   it('should throw an error with just the message when the server responds with an error with a message property in the body', async () => {
     const message = 'Failed to connect to Postgres instance';
     mockFetch(
@@ -85,6 +85,40 @@ describe('fetch', () => {
       )
     ).to.eventually.be.rejectedWith(JSON.stringify(json));
   });
+  it.only('should throw a stringified message when the server responds with an error without a message property in the body', async () => {
+    const json = {
+      'data': { 'abc': 'def' },
+      'errors': [
+        {
+          'message':
+            'SQL query error: pq: duplicate key value violates unique constraint movie_pkey',
+          'locations': [],
+          'path': ['the_matrix'],
+          'extensions': null
+        }
+      ]
+    };
+    mockFetch(json, false);
+    await expect(
+      dcFetch(
+        'http://localhost',
+        {
+          name: 'n',
+          operationName: 'n',
+          variables: {}
+        },
+        {} as AbortController,
+        null,
+        null,
+        null,
+        false,
+        CallerSdkTypeEnum.Base
+      )
+    ).to.eventually.be.rejected.then(error => {
+      expect(error.response.data).to.eq(json.data);
+      expect(error.response.errors).to.eq(json.errors);
+    });
+  });
   it('should assign different values to custom headers based on the _callerSdkType argument (_isUsingGen is false)', async () => {
     const json = {
       code: 200,

From 763dcd3f32cb43d2382b8452fbb683c7af20808d Mon Sep 17 00:00:00 2001
From: Maneesh Tewani <mtewani@google.com>
Date: Fri, 28 Feb 2025 15:38:12 -0800
Subject: [PATCH 06/16] Removed only

---
 packages/data-connect/test/unit/fetch.test.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/data-connect/test/unit/fetch.test.ts b/packages/data-connect/test/unit/fetch.test.ts
index 688886934d7..6cf2750d50d 100644
--- a/packages/data-connect/test/unit/fetch.test.ts
+++ b/packages/data-connect/test/unit/fetch.test.ts
@@ -34,7 +34,7 @@ function mockFetch(json: object, reject: boolean): sinon.SinonStub {
   initializeFetch(fakeFetchImpl);
   return fakeFetchImpl;
 }
-describe.only('fetch', () => {
+describe('fetch', () => {
   it('should throw an error with just the message when the server responds with an error with a message property in the body', async () => {
     const message = 'Failed to connect to Postgres instance';
     mockFetch(
@@ -85,7 +85,7 @@ describe.only('fetch', () => {
       )
     ).to.eventually.be.rejectedWith(JSON.stringify(json));
   });
-  it.only('should throw a stringified message when the server responds with an error without a message property in the body', async () => {
+  it('should throw a stringified message when the server responds with an error without a message property in the body', async () => {
     const json = {
       'data': { 'abc': 'def' },
       'errors': [

From 8978a654e3efc7845565b7876648ed537c8ddd3f Mon Sep 17 00:00:00 2001
From: Maneesh Tewani <mtewani@google.com>
Date: Fri, 28 Feb 2025 15:41:03 -0800
Subject: [PATCH 07/16] Removed only

---
 packages/data-connect/src/network/fetch.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/packages/data-connect/src/network/fetch.ts b/packages/data-connect/src/network/fetch.ts
index eb1d22b6a3f..abcb4966d70 100644
--- a/packages/data-connect/src/network/fetch.ts
+++ b/packages/data-connect/src/network/fetch.ts
@@ -111,7 +111,6 @@ export function dcFetch<T, U>(
       return jsonResponse;
     })
     .then(res => {
-      console.log(res.errors);
       if (res.errors && res.errors.length) {
         const stringified = JSON.stringify(res.errors);
         const response: DataConnectOperationResponse = {

From 1ce98e6ed1026222036dee03ed7dea13e876f391 Mon Sep 17 00:00:00 2001
From: Maneesh Tewani <mtewani@google.com>
Date: Wed, 19 Mar 2025 14:42:35 -0700
Subject: [PATCH 08/16] Updated error type name

---
 packages/data-connect/src/core/error.ts | 20 +++-----------------
 1 file changed, 3 insertions(+), 17 deletions(-)

diff --git a/packages/data-connect/src/core/error.ts b/packages/data-connect/src/core/error.ts
index 3c817f616c3..87e9160f0de 100644
--- a/packages/data-connect/src/core/error.ts
+++ b/packages/data-connect/src/core/error.ts
@@ -44,22 +44,13 @@ export class DataConnectError extends FirebaseError {
   readonly name: string = 'DataConnectError';
 
   /** @hideconstructor */
-  constructor(
-    /**
-     * The backend error code associated with this error.
-     */
-    readonly code: DataConnectErrorCode,
-    /**
-     * A custom error description.
-     */
-    message: string
-  ) {
+  constructor(code: Code, message: string) {
     super(code, message);
 
     // Ensure the instanceof operator works as expected on subclasses of Error.
     // See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error#custom_error_types
     // and https://www.typescriptlang.org/docs/handbook/release-notes/typescript-2-2.html#support-for-newtarget
-    Object.setPrototypeOf(this, new.target.prototype);
+    Object.setPrototypeOf(this, DataConnectError.prototype);
   }
 
   /** @internal */
@@ -78,13 +69,8 @@ export class DataConnectOperationError extends DataConnectError {
 
   /** @hideconstructor */
   constructor(message: string, response: DataConnectOperationResponse) {
-    super('partial-error', message);
+    super(Code.PARTIAL_ERROR, message);
     this.response = response;
-
-    // Ensure the instanceof operator works as expected on subclasses of Error.
-    // See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error#custom_error_types
-    // and https://www.typescriptlang.org/docs/handbook/release-notes/typescript-2-2.html#support-for-newtarget
-    Object.setPrototypeOf(this, new.target.prototype);
   }
 }
 

From c61652841da66418763e030578147fef8e4273b1 Mon Sep 17 00:00:00 2001
From: Maneesh Tewani <mtewani@google.com>
Date: Wed, 19 Mar 2025 14:44:06 -0700
Subject: [PATCH 09/16] Updated data connect API

---
 common/api-review/data-connect.api.md | 41 ++++++---------------------
 1 file changed, 8 insertions(+), 33 deletions(-)

diff --git a/common/api-review/data-connect.api.md b/common/api-review/data-connect.api.md
index 1b93be0e9c3..383d1ae33e1 100644
--- a/common/api-review/data-connect.api.md
+++ b/common/api-review/data-connect.api.md
@@ -52,36 +52,6 @@ export class DataConnect {
     setInitialized(): void;
 }
 
-// @public
-export class DataConnectError extends FirebaseError {
-    readonly code: DataConnectErrorCode;
-}
-
-// @public (undocumented)
-export type DataConnectErrorCode = 'other' | 'already-initialized' | 'not-initialized' | 'not-supported' | 'invalid-argument' | 'partial-error' | 'unauthorized';
-
-// @public
-export class DataConnectOperationError extends DataConnectError {
-    /* Excluded from this release type: name */
-    readonly response: DataConnectOperationResponse;
-}
-
-// @public (undocumented)
-export interface DataConnectOperationErrorInfo {
-    // (undocumented)
-    readonly message: string;
-    // (undocumented)
-    readonly path: Array<string | number>;
-}
-
-// @public (undocumented)
-export interface DataConnectOperationResponse {
-    // (undocumented)
-    readonly data?: Record<string, unknown> | null;
-    // (undocumented)
-    readonly errors: DataConnectOperationErrorInfo[];
-}
-
 // @public
 export interface DataConnectOptions extends ConnectorConfig {
     // (undocumented)
@@ -97,7 +67,7 @@ export interface DataConnectResult<Data, Variables> extends OpResult<Data> {
 // @public
 export interface DataConnectSubscription<Data, Variables> {
     // (undocumented)
-    errCallback?: (e?: DataConnectError) => void;
+    errCallback?: (e?: FirebaseError) => void;
     // (undocumented)
     unsubscribe: () => void;
     // (undocumented)
@@ -113,6 +83,9 @@ export function executeMutation<Data, Variables>(mutationRef: MutationRef<Data,
 // @public
 export function executeQuery<Data, Variables>(queryRef: QueryRef<Data, Variables>): QueryPromise<Data, Variables>;
 
+// @public (undocumented)
+export const fdcSymbol: unique symbol;
+
 // @public
 export function getDataConnect(options: ConnectorConfig): DataConnect;
 
@@ -148,13 +121,15 @@ export interface MutationResult<Data, Variables> extends DataConnectResult<Data,
 export type OnCompleteSubscription = () => void;
 
 // @public
-export type OnErrorSubscription = (err?: DataConnectError) => void;
+export type OnErrorSubscription = (err?: FirebaseError) => void;
 
 // @public
 export type OnResultSubscription<Data, Variables> = (res: QueryResult<Data, Variables>) => void;
 
 // @public (undocumented)
-export interface OperationRef<_Data, Variables> {
+export interface OperationRef<Data, Variables> {
+    // (undocumented)
+    [fdcSymbol]?: Data;
     // (undocumented)
     dataConnect: DataConnect;
     // (undocumented)

From 1f5fa0305607cac1d43174512f1f8f5dc002c62d Mon Sep 17 00:00:00 2001
From: Maneesh Tewani <mtewani@google.com>
Date: Wed, 19 Mar 2025 14:56:12 -0700
Subject: [PATCH 10/16] Updated typings

---
 common/api-review/data-connect.api.md  | 40 ++++++++++++++++++++------
 packages/data-connect/src/api/index.ts |  2 +-
 2 files changed, 33 insertions(+), 9 deletions(-)

diff --git a/common/api-review/data-connect.api.md b/common/api-review/data-connect.api.md
index 383d1ae33e1..0652d07820f 100644
--- a/common/api-review/data-connect.api.md
+++ b/common/api-review/data-connect.api.md
@@ -52,6 +52,35 @@ export class DataConnect {
     setInitialized(): void;
 }
 
+// @public
+export class DataConnectError extends FirebaseError {
+    }
+
+// @public (undocumented)
+export type DataConnectErrorCode = 'other' | 'already-initialized' | 'not-initialized' | 'not-supported' | 'invalid-argument' | 'partial-error' | 'unauthorized';
+
+// @public
+export class DataConnectOperationError extends DataConnectError {
+    /* Excluded from this release type: name */
+    readonly response: DataConnectOperationResponse;
+}
+
+// @public (undocumented)
+export interface DataConnectOperationErrorInfo {
+    // (undocumented)
+    readonly message: string;
+    // (undocumented)
+    readonly path: Array<string | number>;
+}
+
+// @public (undocumented)
+export interface DataConnectOperationResponse {
+    // (undocumented)
+    readonly data?: Record<string, unknown> | null;
+    // (undocumented)
+    readonly errors: DataConnectOperationErrorInfo[];
+}
+
 // @public
 export interface DataConnectOptions extends ConnectorConfig {
     // (undocumented)
@@ -67,7 +96,7 @@ export interface DataConnectResult<Data, Variables> extends OpResult<Data> {
 // @public
 export interface DataConnectSubscription<Data, Variables> {
     // (undocumented)
-    errCallback?: (e?: FirebaseError) => void;
+    errCallback?: (e?: DataConnectError) => void;
     // (undocumented)
     unsubscribe: () => void;
     // (undocumented)
@@ -83,9 +112,6 @@ export function executeMutation<Data, Variables>(mutationRef: MutationRef<Data,
 // @public
 export function executeQuery<Data, Variables>(queryRef: QueryRef<Data, Variables>): QueryPromise<Data, Variables>;
 
-// @public (undocumented)
-export const fdcSymbol: unique symbol;
-
 // @public
 export function getDataConnect(options: ConnectorConfig): DataConnect;
 
@@ -121,15 +147,13 @@ export interface MutationResult<Data, Variables> extends DataConnectResult<Data,
 export type OnCompleteSubscription = () => void;
 
 // @public
-export type OnErrorSubscription = (err?: FirebaseError) => void;
+export type OnErrorSubscription = (err?: DataConnectError) => void;
 
 // @public
 export type OnResultSubscription<Data, Variables> = (res: QueryResult<Data, Variables>) => void;
 
 // @public (undocumented)
-export interface OperationRef<Data, Variables> {
-    // (undocumented)
-    [fdcSymbol]?: Data;
+export interface OperationRef<_Data, Variables> {
     // (undocumented)
     dataConnect: DataConnect;
     // (undocumented)
diff --git a/packages/data-connect/src/api/index.ts b/packages/data-connect/src/api/index.ts
index 71bd95557dc..8f84e23bdaf 100644
--- a/packages/data-connect/src/api/index.ts
+++ b/packages/data-connect/src/api/index.ts
@@ -25,7 +25,7 @@ export { validateArgs } from '../util/validateArgs';
 
 export { DataConnectError, DataConnectOperationError } from '../core/error';
 
-export type {
+export {
   DataConnectErrorCode,
   DataConnectOperationResponse,
   DataConnectOperationErrorInfo

From a41d2ef0da76c583a0ae2d2ad2e513d7080b8dc4 Mon Sep 17 00:00:00 2001
From: Maneesh Tewani <maneesht@users.noreply.github.com>
Date: Wed, 19 Mar 2025 14:57:53 -0700
Subject: [PATCH 11/16] Create sharp-nails-glow.md

---
 .changeset/sharp-nails-glow.md | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .changeset/sharp-nails-glow.md

diff --git a/.changeset/sharp-nails-glow.md b/.changeset/sharp-nails-glow.md
new file mode 100644
index 00000000000..68c5e68c39d
--- /dev/null
+++ b/.changeset/sharp-nails-glow.md
@@ -0,0 +1,5 @@
+---
+"@firebase/data-connect": patch
+---
+
+Expose partial errors to the user.

From 23b7845015fe45e5caba9820c1afb9266cfe8a61 Mon Sep 17 00:00:00 2001
From: Maneesh Tewani <mtewani@google.com>
Date: Wed, 19 Mar 2025 15:46:23 -0700
Subject: [PATCH 12/16] Addressed comments

---
 packages/data-connect/src/api/index.ts | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/packages/data-connect/src/api/index.ts b/packages/data-connect/src/api/index.ts
index 8f84e23bdaf..cf3f6fd5d47 100644
--- a/packages/data-connect/src/api/index.ts
+++ b/packages/data-connect/src/api/index.ts
@@ -22,11 +22,10 @@ export * from './Mutation';
 export * from './query';
 export { setLogLevel } from '../logger';
 export { validateArgs } from '../util/validateArgs';
-
-export { DataConnectError, DataConnectOperationError } from '../core/error';
-
 export {
   DataConnectErrorCode,
+  DataConnectError,
+  DataConnectOperationError,
   DataConnectOperationResponse,
   DataConnectOperationErrorInfo
 } from '../core/error';

From 12ce1bd7494e1094e35dac2c543188e38c3bdffd Mon Sep 17 00:00:00 2001
From: Maneesh Tewani <mtewani@google.com>
Date: Thu, 20 Mar 2025 09:32:35 -0700
Subject: [PATCH 13/16] Addressed comments

---
 packages/data-connect/src/api/index.ts     |  4 ++--
 packages/data-connect/src/core/error.ts    | 10 +++++-----
 packages/data-connect/src/network/fetch.ts |  4 ++--
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/packages/data-connect/src/api/index.ts b/packages/data-connect/src/api/index.ts
index cf3f6fd5d47..dcd48485571 100644
--- a/packages/data-connect/src/api/index.ts
+++ b/packages/data-connect/src/api/index.ts
@@ -26,6 +26,6 @@ export {
   DataConnectErrorCode,
   DataConnectError,
   DataConnectOperationError,
-  DataConnectOperationResponse,
-  DataConnectOperationErrorInfo
+  DataConnectOperationFailureResponse,
+  DataConnectOperationFailureResponseErrorInfo
 } from '../core/error';
diff --git a/packages/data-connect/src/core/error.ts b/packages/data-connect/src/core/error.ts
index 87e9160f0de..b1246969e48 100644
--- a/packages/data-connect/src/core/error.ts
+++ b/packages/data-connect/src/core/error.ts
@@ -65,16 +65,16 @@ export class DataConnectOperationError extends DataConnectError {
   readonly name: string = 'DataConnectOperationError';
 
   /** The response received from the backend. */
-  readonly response: DataConnectOperationResponse;
+  readonly response: DataConnectOperationFailureResponse;
 
   /** @hideconstructor */
-  constructor(message: string, response: DataConnectOperationResponse) {
+  constructor(message: string, response: DataConnectOperationFailureResponse) {
     super(Code.PARTIAL_ERROR, message);
     this.response = response;
   }
 }
 
-export interface DataConnectOperationResponse {
+export interface DataConnectOperationFailureResponse {
   // The "data" provided by the backend in the response message.
   //
   // Will be `undefined` if no "data" was provided in the response message.
@@ -84,12 +84,12 @@ export interface DataConnectOperationResponse {
   readonly data?: Record<string, unknown> | null;
 
   // The list of errors provided by the backend in the response message.
-  readonly errors: DataConnectOperationErrorInfo[];
+  readonly errors: DataConnectOperationFailureResponseErrorInfo[];
 }
 
 // Information about the error, as provided in the response from the backend.
 // See https://spec.graphql.org/draft/#sec-Errors
-export interface DataConnectOperationErrorInfo {
+export interface DataConnectOperationFailureResponseErrorInfo {
   // The error message.
   readonly message: string;
 
diff --git a/packages/data-connect/src/network/fetch.ts b/packages/data-connect/src/network/fetch.ts
index abcb4966d70..8353c6b99ab 100644
--- a/packages/data-connect/src/network/fetch.ts
+++ b/packages/data-connect/src/network/fetch.ts
@@ -19,7 +19,7 @@ import {
   Code,
   DataConnectError,
   DataConnectOperationError,
-  DataConnectOperationResponse
+  DataConnectOperationFailureResponse
 } from '../core/error';
 import { SDK_VERSION } from '../core/version';
 import { logDebug, logError } from '../logger';
@@ -113,7 +113,7 @@ export function dcFetch<T, U>(
     .then(res => {
       if (res.errors && res.errors.length) {
         const stringified = JSON.stringify(res.errors);
-        const response: DataConnectOperationResponse = {
+        const response: DataConnectOperationFailureResponse = {
           errors: res.errors,
           data: res.data
         };

From d650f5d0710518d71774173ed24708a7ed7b551f Mon Sep 17 00:00:00 2001
From: Maneesh Tewani <mtewani@google.com>
Date: Thu, 20 Mar 2025 10:14:14 -0700
Subject: [PATCH 14/16] Updated docgen

---
 common/api-review/data-connect.api.md              | 14 +++++++-------
 .../test/dataconnect/connector/connector.yaml      |  6 +++---
 packages/data-connect/test/mutations.gql           |  6 ------
 3 files changed, 10 insertions(+), 16 deletions(-)
 delete mode 100644 packages/data-connect/test/mutations.gql

diff --git a/common/api-review/data-connect.api.md b/common/api-review/data-connect.api.md
index 0652d07820f..786714361af 100644
--- a/common/api-review/data-connect.api.md
+++ b/common/api-review/data-connect.api.md
@@ -62,23 +62,23 @@ export type DataConnectErrorCode = 'other' | 'already-initialized' | 'not-initia
 // @public
 export class DataConnectOperationError extends DataConnectError {
     /* Excluded from this release type: name */
-    readonly response: DataConnectOperationResponse;
+    readonly response: DataConnectOperationFailureResponse;
 }
 
 // @public (undocumented)
-export interface DataConnectOperationErrorInfo {
+export interface DataConnectOperationFailureResponse {
     // (undocumented)
-    readonly message: string;
+    readonly data?: Record<string, unknown> | null;
     // (undocumented)
-    readonly path: Array<string | number>;
+    readonly errors: DataConnectOperationFailureResponseErrorInfo[];
 }
 
 // @public (undocumented)
-export interface DataConnectOperationResponse {
+export interface DataConnectOperationFailureResponseErrorInfo {
     // (undocumented)
-    readonly data?: Record<string, unknown> | null;
+    readonly message: string;
     // (undocumented)
-    readonly errors: DataConnectOperationErrorInfo[];
+    readonly path: Array<string | number>;
 }
 
 // @public
diff --git a/packages/data-connect/test/dataconnect/connector/connector.yaml b/packages/data-connect/test/dataconnect/connector/connector.yaml
index e945b44b00c..e4cde271588 100644
--- a/packages/data-connect/test/dataconnect/connector/connector.yaml
+++ b/packages/data-connect/test/dataconnect/connector/connector.yaml
@@ -1,6 +1,6 @@
 connectorId: "tests"
 authMode: "PUBLIC" 
 generate:
-    javascriptSdk:
-      outputDir: "./gen/web"
-      package: "@test-app/tests"
+  javascriptSdk:
+    outputDir: "./gen/web"
+    package: "@test-app/tests"
diff --git a/packages/data-connect/test/mutations.gql b/packages/data-connect/test/mutations.gql
deleted file mode 100644
index a826a39529a..00000000000
--- a/packages/data-connect/test/mutations.gql
+++ /dev/null
@@ -1,6 +0,0 @@
-mutation seedDatabase($id: UUID!, $content: String!) @auth(level: PUBLIC) {
-    post: post_insert(data: {id: $id, content: $content})
-}
-mutation removePost($id: UUID!) @auth(level: PUBLIC) {
-    post: post_delete(id: $id)
-}
\ No newline at end of file

From e1f55338f00f4504259489864f5786cd297c02e2 Mon Sep 17 00:00:00 2001
From: Maneesh Tewani <mtewani@google.com>
Date: Thu, 20 Mar 2025 15:23:44 -0700
Subject: [PATCH 15/16] Bumped emulator version

---
 packages/data-connect/test/emulatorSeeder.ts  | 68 -------------------
 .../emulators/dataconnect-emulator.ts         |  2 +-
 .../emulator-testing/emulators/emulator.ts    |  5 +-
 3 files changed, 5 insertions(+), 70 deletions(-)
 delete mode 100644 packages/data-connect/test/emulatorSeeder.ts

diff --git a/packages/data-connect/test/emulatorSeeder.ts b/packages/data-connect/test/emulatorSeeder.ts
deleted file mode 100644
index 1517deb90f8..00000000000
--- a/packages/data-connect/test/emulatorSeeder.ts
+++ /dev/null
@@ -1,68 +0,0 @@
-/**
- * @license
- * Copyright 2024 Google LLC
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *   http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-import fs from 'fs';
-import * as path from 'path';
-
-import { ReferenceType } from '../src';
-
-import { EMULATOR_PORT } from './util';
-
-export interface SeedInfo {
-  type: ReferenceType;
-  name: string;
-}
-export async function setupQueries(
-  schema: string,
-  seedInfoArray: SeedInfo[]
-): Promise<Response> {
-  const schemaPath = path.resolve(__dirname, schema);
-  const schemaFileContents = fs.readFileSync(schemaPath).toString();
-  const toWrite = {
-    'service_id': 'l',
-    'schema': {
-      'files': [
-        {
-          'path': `schema/${schema}`,
-          'content': schemaFileContents
-        }
-      ]
-    },
-    'connectors': {
-      'c': {
-        'files': seedInfoArray.map(seedInfo => {
-          const fileName = seedInfo.name + '.gql';
-          const operationFilePath = path.resolve(__dirname, fileName);
-          const operationFileContents = fs
-            .readFileSync(operationFilePath)
-            .toString();
-          return {
-            path: `operations/${seedInfo.name}.gql`,
-            content: operationFileContents
-          };
-        })
-      }
-    },
-    // eslint-disable-next-line camelcase
-    connection_string:
-      'postgresql://postgres:secretpassword@localhost:5432/postgres?sslmode=disable'
-  };
-  return fetch(`http://localhost:${EMULATOR_PORT}/setupSchema`, {
-    method: 'POST',
-    body: JSON.stringify(toWrite)
-  });
-}
diff --git a/scripts/emulator-testing/emulators/dataconnect-emulator.ts b/scripts/emulator-testing/emulators/dataconnect-emulator.ts
index 5cea83b073b..9dc6add5df1 100644
--- a/scripts/emulator-testing/emulators/dataconnect-emulator.ts
+++ b/scripts/emulator-testing/emulators/dataconnect-emulator.ts
@@ -18,7 +18,7 @@
 import { platform } from 'os';
 import { Emulator } from './emulator';
 
-const DATACONNECT_EMULATOR_VERSION = '1.7.5';
+const DATACONNECT_EMULATOR_VERSION = '1.9.2';
 
 export class DataConnectEmulator extends Emulator {
   constructor(port = 9399) {
diff --git a/scripts/emulator-testing/emulators/emulator.ts b/scripts/emulator-testing/emulators/emulator.ts
index 0eeb1ca88bd..b9bd81b2005 100644
--- a/scripts/emulator-testing/emulators/emulator.ts
+++ b/scripts/emulator-testing/emulators/emulator.ts
@@ -146,6 +146,7 @@ export abstract class Emulator {
       if (this.isDataConnect) {
         const dataConnectConfigDir = this.findDataConnectConfigDir();
         promise = spawn(this.binaryPath, [
+          '--logtostderr',
           '--v=2',
           'dev',
           `--listen=127.0.0.1:${this.port},[::1]:${this.port}`,
@@ -155,6 +156,9 @@ export abstract class Emulator {
         promise.childProcess.stderr?.on('data', res =>
           console.log(res.toString())
         );
+        promise.childProcess.stderr?.on('error', res =>
+          console.log(res.toString())
+        );
       } else {
         promise = spawn(
           'java',
@@ -174,7 +178,6 @@ export abstract class Emulator {
       promise.catch(reject);
       this.emulator = promise.childProcess;
 
-      console.log(`Waiting for emulator to start up ...`);
       // NOTE: Normally the emulator starts up within a few seconds.
       // However, our sdk test suite launches tests from 20+ packages in parallel, which slows
       // down the startup substantially. In such case for the emulator to start, it can take

From c6955234c32611ab1b13a46bb1856240e2ecb476 Mon Sep 17 00:00:00 2001
From: Maneesh Tewani <mtewani@google.com>
Date: Thu, 20 Mar 2025 18:47:17 -0700
Subject: [PATCH 16/16] Brought back log

---
 scripts/emulator-testing/emulators/emulator.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/scripts/emulator-testing/emulators/emulator.ts b/scripts/emulator-testing/emulators/emulator.ts
index b9bd81b2005..01fbe66fa13 100644
--- a/scripts/emulator-testing/emulators/emulator.ts
+++ b/scripts/emulator-testing/emulators/emulator.ts
@@ -178,6 +178,7 @@ export abstract class Emulator {
       promise.catch(reject);
       this.emulator = promise.childProcess;
 
+      console.log(`Waiting for emulator to start up ...`);
       // NOTE: Normally the emulator starts up within a few seconds.
       // However, our sdk test suite launches tests from 20+ packages in parallel, which slows
       // down the startup substantially. In such case for the emulator to start, it can take