From 13c1b1db4d1eb80ff629cd311cb36846657ace6a Mon Sep 17 00:00:00 2001
From: Kevin Elko <kjelko@google.com>
Date: Wed, 13 Nov 2024 11:45:01 -0500
Subject: [PATCH 01/10] add serialization method to server side remote config

---
 src/remote-config/remote-config-api.ts | 18 ++++++++++++++++++
 src/remote-config/remote-config.ts     | 12 ++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/src/remote-config/remote-config-api.ts b/src/remote-config/remote-config-api.ts
index 4dfa1da023..908d35cbe8 100644
--- a/src/remote-config/remote-config-api.ts
+++ b/src/remote-config/remote-config-api.ts
@@ -727,6 +727,24 @@ export interface ServerConfig {
    * @returns The value for the given key.
    */
   getValue(key: string): Value;
+
+  /**
+   * Returns a JSON-serializable representation of the current config values, including an eTag
+   * that can be utilized by the Remote Config web client SDK.
+   * 
+   * @returns JSON-serializable config object.
+   */
+  serializeForClient(): FetchResponse;
+}
+
+/**
+ * JSON-serializable representation of evaluated config values. This can be consumed by 
+ * Remote Config web client SDKs.
+ */
+export interface FetchResponse {
+  status: number;
+  eTag?: string;
+  config?: {[key: string]: string};
 }
 
 /**
diff --git a/src/remote-config/remote-config.ts b/src/remote-config/remote-config.ts
index c529501315..f46eb8be80 100644
--- a/src/remote-config/remote-config.ts
+++ b/src/remote-config/remote-config.ts
@@ -41,6 +41,7 @@ import {
   GetServerTemplateOptions,
   InitServerTemplateOptions,
   ServerTemplateDataType,
+  FetchResponse,
 } from './remote-config-api';
 
 /**
@@ -438,6 +439,17 @@ class ServerConfigImpl implements ServerConfig {
   getValue(key: string): Value {
     return this.configValues[key] || new ValueImpl('static');
   }
+  serializeForClient(): FetchResponse {
+    const config: {[key:string]:string} = {};
+    for (const [param, value] of Object.entries(this.configValues)) {
+      config[param] = value.asString();
+    }
+    return  {
+      status: 200,
+      eTag: `etag-${Math.floor(Math.random() * 100000)}`,
+      config,
+    };
+  }
 }
 
 /**

From 62bf436e7c9848cb8cadfe57e4c298cb8295a6dc Mon Sep 17 00:00:00 2001
From: Kevin Elko <kjelko@google.com>
Date: Tue, 3 Dec 2024 15:23:05 -0500
Subject: [PATCH 02/10] update with latest changes

---
 src/remote-config/index.ts             | 21 +++++++++++++++++++++
 src/remote-config/remote-config-api.ts |  7 +++----
 src/remote-config/remote-config.ts     | 13 ++-----------
 3 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/src/remote-config/index.ts b/src/remote-config/index.ts
index 7b66c44ee9..9d9ae39376 100644
--- a/src/remote-config/index.ts
+++ b/src/remote-config/index.ts
@@ -23,6 +23,7 @@
 import { App, getApp } from '../app';
 import { FirebaseApp } from '../app/firebase-app';
 import { RemoteConfig } from './remote-config';
+import { ServerConfig, FetchResponse } from './remote-config-api';
 
 export {
   AndCondition,
@@ -31,6 +32,7 @@ export {
   DefaultConfig,
   EvaluationContext,
   ExplicitParameterValue,
+  FetchResponse,
   GetServerTemplateOptions,
   InAppDefaultValue,
   InitServerTemplateOptions,
@@ -96,3 +98,22 @@ export function getRemoteConfig(app?: App): RemoteConfig {
   const firebaseApp: FirebaseApp = app as FirebaseApp;
   return firebaseApp.getOrInitService('remoteConfig', (app) => new RemoteConfig(app));
 }
+
+/**
+   * Returns a JSON-serializable representation of the current config values, including an eTag
+   * that can be utilized by the Remote Config web client SDK.
+   * 
+   * @returns JSON-serializable config object.
+   */
+export function buildFetchResponse(serverConfig: ServerConfig, etag?: string): FetchResponse {
+  const config: {[key:string]: string} = {};
+  for (const [param, value] of Object.entries(serverConfig.getAll())) {
+    config[param] = value.asString();
+  }
+  // TODO - compute etag
+  return  {
+    status: 200,
+    eTag: `etag-${Math.floor(Math.random() * 100000)}`,
+    config,
+  };
+}
\ No newline at end of file
diff --git a/src/remote-config/remote-config-api.ts b/src/remote-config/remote-config-api.ts
index 908d35cbe8..87fd85fba5 100644
--- a/src/remote-config/remote-config-api.ts
+++ b/src/remote-config/remote-config-api.ts
@@ -729,12 +729,11 @@ export interface ServerConfig {
   getValue(key: string): Value;
 
   /**
-   * Returns a JSON-serializable representation of the current config values, including an eTag
-   * that can be utilized by the Remote Config web client SDK.
+   * Returns all config values.
    * 
-   * @returns JSON-serializable config object.
+   * @returns A map of all config keys to their values.
    */
-  serializeForClient(): FetchResponse;
+  getAll(): {[key:string]: Value}
 }
 
 /**
diff --git a/src/remote-config/remote-config.ts b/src/remote-config/remote-config.ts
index f46eb8be80..9355452948 100644
--- a/src/remote-config/remote-config.ts
+++ b/src/remote-config/remote-config.ts
@@ -41,7 +41,6 @@ import {
   GetServerTemplateOptions,
   InitServerTemplateOptions,
   ServerTemplateDataType,
-  FetchResponse,
 } from './remote-config-api';
 
 /**
@@ -439,16 +438,8 @@ class ServerConfigImpl implements ServerConfig {
   getValue(key: string): Value {
     return this.configValues[key] || new ValueImpl('static');
   }
-  serializeForClient(): FetchResponse {
-    const config: {[key:string]:string} = {};
-    for (const [param, value] of Object.entries(this.configValues)) {
-      config[param] = value.asString();
-    }
-    return  {
-      status: 200,
-      eTag: `etag-${Math.floor(Math.random() * 100000)}`,
-      config,
-    };
+  getAll(): {[key: string]: Value} {
+    return {...this.configValues};
   }
 }
 

From 812f374adabce5e37c8043abda9a03e418944781 Mon Sep 17 00:00:00 2001
From: kjelko <kjelko@google.com>
Date: Wed, 4 Dec 2024 15:54:10 -0500
Subject: [PATCH 03/10] restructure as a class, add documentation

---
 src/remote-config/index.ts                    | 24 +-------
 src/remote-config/remote-config-api.ts        |  4 +-
 src/remote-config/remote-config.ts            | 50 +++++++++++++++-
 test/unit/remote-config/remote-config.spec.ts | 60 +++++++++++++++++++
 4 files changed, 113 insertions(+), 25 deletions(-)

diff --git a/src/remote-config/index.ts b/src/remote-config/index.ts
index 9d9ae39376..cb3383e3d3 100644
--- a/src/remote-config/index.ts
+++ b/src/remote-config/index.ts
@@ -23,7 +23,6 @@
 import { App, getApp } from '../app';
 import { FirebaseApp } from '../app/firebase-app';
 import { RemoteConfig } from './remote-config';
-import { ServerConfig, FetchResponse } from './remote-config-api';
 
 export {
   AndCondition,
@@ -32,7 +31,7 @@ export {
   DefaultConfig,
   EvaluationContext,
   ExplicitParameterValue,
-  FetchResponse,
+  FetchResponseData,
   GetServerTemplateOptions,
   InAppDefaultValue,
   InitServerTemplateOptions,
@@ -62,7 +61,7 @@ export {
   ValueSource,
   Version,
 } from './remote-config-api';
-export { RemoteConfig } from './remote-config';
+export { RemoteConfig, RemoteConfigFetchResponse } from './remote-config';
 
 /**
  * Gets the {@link RemoteConfig} service for the default app or a given app.
@@ -97,23 +96,4 @@ export function getRemoteConfig(app?: App): RemoteConfig {
 
   const firebaseApp: FirebaseApp = app as FirebaseApp;
   return firebaseApp.getOrInitService('remoteConfig', (app) => new RemoteConfig(app));
-}
-
-/**
-   * Returns a JSON-serializable representation of the current config values, including an eTag
-   * that can be utilized by the Remote Config web client SDK.
-   * 
-   * @returns JSON-serializable config object.
-   */
-export function buildFetchResponse(serverConfig: ServerConfig, etag?: string): FetchResponse {
-  const config: {[key:string]: string} = {};
-  for (const [param, value] of Object.entries(serverConfig.getAll())) {
-    config[param] = value.asString();
-  }
-  // TODO - compute etag
-  return  {
-    status: 200,
-    eTag: `etag-${Math.floor(Math.random() * 100000)}`,
-    config,
-  };
 }
\ No newline at end of file
diff --git a/src/remote-config/remote-config-api.ts b/src/remote-config/remote-config-api.ts
index 87fd85fba5..6d83757455 100644
--- a/src/remote-config/remote-config-api.ts
+++ b/src/remote-config/remote-config-api.ts
@@ -740,9 +740,9 @@ export interface ServerConfig {
  * JSON-serializable representation of evaluated config values. This can be consumed by 
  * Remote Config web client SDKs.
  */
-export interface FetchResponse {
+export interface FetchResponseData {
   status: number;
-  eTag?: string;
+  eTag: string;
   config?: {[key: string]: string};
 }
 
diff --git a/src/remote-config/remote-config.ts b/src/remote-config/remote-config.ts
index 9355452948..27baaa7e6e 100644
--- a/src/remote-config/remote-config.ts
+++ b/src/remote-config/remote-config.ts
@@ -15,6 +15,7 @@
  */
 
 import { App } from '../app';
+import * as utils from '../utils/index';
 import * as validator from '../utils/validator';
 import { FirebaseRemoteConfigError, RemoteConfigApiClient } from './remote-config-api-client-internal';
 import { ConditionEvaluator } from './condition-evaluator-internal';
@@ -41,6 +42,7 @@ import {
   GetServerTemplateOptions,
   InitServerTemplateOptions,
   ServerTemplateDataType,
+  FetchResponseData,
 } from './remote-config-api';
 
 /**
@@ -439,7 +441,7 @@ class ServerConfigImpl implements ServerConfig {
     return this.configValues[key] || new ValueImpl('static');
   }
   getAll(): {[key: string]: Value} {
-    return {...this.configValues};
+    return { ...this.configValues };
   }
 }
 
@@ -616,3 +618,49 @@ class VersionImpl implements Version {
     return validator.isNonEmptyString(timestamp) && (new Date(timestamp)).getTime() > 0;
   }
 }
+
+/**
+ * Represents a fetch response that can be used to interact with RC's client SDK.
+ */
+export class RemoteConfigFetchResponse {
+  private response: FetchResponseData;
+
+  constructor(app: App, serverConfig: ServerConfig, eTag?: string) {
+    const config: {[key:string]: string} = {};
+    for (const [param, value] of Object.entries(serverConfig.getAll())) {
+      config[param] = value.asString();
+    }
+
+    const currentEtag = this.processEtag(config, app);
+
+    if (currentEtag === eTag) {
+      this.response = {
+        status: 304,
+        eTag,
+      };
+    } else {
+      this.response = {
+        status: 200,
+        eTag: currentEtag,
+        config,
+      }
+    }
+  }
+
+  toJSON(): FetchResponseData {
+    return this.response;
+  }
+
+  private processEtag(config: {[key:string]: string}, app: App): string {
+    const configJson = JSON.stringify(config);
+    let hash = 0;
+    for (let i = 0; i < configJson.length; i++) {
+      const char = configJson.charCodeAt(i);
+      hash = (hash << 5) - hash + char;
+      hash |= 0;
+    }
+    const projectId = utils.getExplicitProjectId(app);
+    const parts = ['etag', projectId, 'firebase-server', 'fetch', hash];
+    return parts.filter(a => !!a).join('-');
+  }
+}
\ No newline at end of file
diff --git a/test/unit/remote-config/remote-config.spec.ts b/test/unit/remote-config/remote-config.spec.ts
index 526dc0699e..a69d9c44af 100644
--- a/test/unit/remote-config/remote-config.spec.ts
+++ b/test/unit/remote-config/remote-config.spec.ts
@@ -26,6 +26,7 @@ import {
   RemoteConfigCondition,
   TagColor,
   ListVersionsResult,
+  RemoteConfigFetchResponse,
 } from '../../../src/remote-config/index';
 import { FirebaseApp } from '../../../src/app/firebase-app';
 import * as mocks from '../../resources/mocks';
@@ -1391,6 +1392,65 @@ describe('RemoteConfig', () => {
     });
   });
 
+  describe('RemoteConfigFetchResponse', () => {
+    it('should return a 200 response with no etag', () => {
+      const templateData = deepCopy(SERVER_REMOTE_CONFIG_RESPONSE) as ServerTemplateData;
+      // Defines remote parameter values.
+      templateData.parameters = {
+        dog_type: {
+          defaultValue: {
+            value: 'beagle'
+          }
+        }
+      };
+      const template = remoteConfig.initServerTemplate({ template: templateData });
+      const fetchResponse = new RemoteConfigFetchResponse(mockApp, template.evaluate());
+      expect(fetchResponse.toJSON()).deep.equals({
+        status: 200,
+        eTag: 'etag-project_id-firebase-server-fetch--2039110429',
+        config: { 'dog_type': 'beagle' }
+      });
+    });
+  
+    it('should return a 200 response with a stale etag', () => {
+      const templateData = deepCopy(SERVER_REMOTE_CONFIG_RESPONSE) as ServerTemplateData;
+      // Defines remote parameter values.
+      templateData.parameters = {
+        dog_type: {
+          defaultValue: {
+            value: 'beagle'
+          }
+        }
+      };
+      const template = remoteConfig.initServerTemplate({ template: templateData });
+      const fetchResponse = new RemoteConfigFetchResponse(mockApp, template.evaluate(), 'fake-etag');
+      expect(fetchResponse.toJSON()).deep.equals({
+        status: 200,
+        eTag: 'etag-project_id-firebase-server-fetch--2039110429',
+        config: { 'dog_type': 'beagle' }
+      });
+    });
+  
+    it('should return a 304 repsonse with matching etag', () => {
+      const templateData = deepCopy(SERVER_REMOTE_CONFIG_RESPONSE) as ServerTemplateData;
+      // Defines remote parameter values.
+      templateData.parameters = {
+        dog_type: {
+          defaultValue: {
+            value: 'beagle'
+          }
+        }
+      };
+      const template = remoteConfig.initServerTemplate({ template: templateData });
+      const fetchResponse = new RemoteConfigFetchResponse(
+        mockApp, template.evaluate(), 'etag-project_id-firebase-server-fetch--2039110429');
+      expect(fetchResponse.toJSON()).deep.equals({
+        status: 304,
+        eTag: 'etag-project_id-firebase-server-fetch--2039110429'
+      });
+    });
+  });
+
   function runInvalidResponseTests(rcOperation: () => Promise<RemoteConfigTemplate>,
     operationName: any): void {
     it('should propagate API errors', () => {

From eaf78e273f5145f7bd6d9c0d6e936c1c79220324 Mon Sep 17 00:00:00 2001
From: kjelko <kjelko@google.com>
Date: Wed, 4 Dec 2024 16:09:54 -0500
Subject: [PATCH 04/10] more tests for server config

---
 src/remote-config/remote-config.ts            |  2 +-
 test/unit/remote-config/remote-config.spec.ts | 37 ++++++++++++++++++-
 2 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/src/remote-config/remote-config.ts b/src/remote-config/remote-config.ts
index 27baaa7e6e..8a60b2cf9c 100644
--- a/src/remote-config/remote-config.ts
+++ b/src/remote-config/remote-config.ts
@@ -663,4 +663,4 @@ export class RemoteConfigFetchResponse {
     const parts = ['etag', projectId, 'firebase-server', 'fetch', hash];
     return parts.filter(a => !!a).join('-');
   }
-}
\ No newline at end of file
+}
diff --git a/test/unit/remote-config/remote-config.spec.ts b/test/unit/remote-config/remote-config.spec.ts
index a69d9c44af..3270492d5d 100644
--- a/test/unit/remote-config/remote-config.spec.ts
+++ b/test/unit/remote-config/remote-config.spec.ts
@@ -1293,13 +1293,46 @@ describe('RemoteConfig', () => {
   // Note the static source is set in the getValue() method, but the other sources
   // are set in the evaluate() method, so these tests span a couple layers.
   describe('ServerConfig', () => {
+    describe('getAll', () => {
+      it('should return all values', () => {
+        const templateData = deepCopy(SERVER_REMOTE_CONFIG_RESPONSE) as ServerTemplateData;
+        templateData.parameters = {
+          dog_type: {
+            defaultValue: {
+              value: 'pug'
+            }
+          },
+          dog_type_enabled: {
+            defaultValue: {
+              value: 'true'
+            }
+          },
+          dog_age: {
+            defaultValue: {
+              value: '22'
+            }
+          },
+          dog_use_inapp_default: {
+            defaultValue: {
+              useInAppDefault: true
+            }
+          },
+        };
+        const template = remoteConfig.initServerTemplate({ template: templateData });
+        const config = template.evaluate().getAll();
+        expect(Object.keys(config)).deep.equal(['dog_type', 'dog_type_enabled', 'dog_age']);
+        expect(config['dog_type'].asString()).to.equal('pug');
+        expect(config['dog_type_enabled'].asBoolean()).to.equal(true);
+        expect(config['dog_age'].asNumber()).to.equal(22);
+      });
+    });
+
     describe('getValue', () => {
       it('should return static when default and remote are not defined', () => {
         const templateData = deepCopy(SERVER_REMOTE_CONFIG_RESPONSE) as ServerTemplateData;
         // Omits remote parameter values.
         templateData.parameters = {
-        };
-        // Omits in-app default values.
+        }
         const template = remoteConfig.initServerTemplate({ template: templateData });
         const config = template.evaluate();
         const value = config.getValue('dog_type');

From e1dff128a4424169a1249864b0ba22b004d19756 Mon Sep 17 00:00:00 2001
From: kjelko <kjelko@google.com>
Date: Fri, 3 Jan 2025 11:59:22 -0500
Subject: [PATCH 05/10] run apidocs

---
 etc/firebase-admin.remote-config.api.md | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/etc/firebase-admin.remote-config.api.md b/etc/firebase-admin.remote-config.api.md
index 68d760468c..0d39f2b0ab 100644
--- a/etc/firebase-admin.remote-config.api.md
+++ b/etc/firebase-admin.remote-config.api.md
@@ -52,6 +52,18 @@ export interface ExplicitParameterValue {
     value: string;
 }
 
+// @public
+export interface FetchResponseData {
+    // (undocumented)
+    config?: {
+        [key: string]: string;
+    };
+    // (undocumented)
+    eTag: string;
+    // (undocumented)
+    status: number;
+}
+
 // Warning: (ae-forgotten-export) The symbol "App" needs to be exported by the entry point index.d.ts
 //
 // @public
@@ -162,6 +174,13 @@ export interface RemoteConfigCondition {
     tagColor?: TagColor;
 }
 
+// @public
+export class RemoteConfigFetchResponse {
+    constructor(app: App, serverConfig: ServerConfig, eTag?: string);
+    // (undocumented)
+    toJSON(): FetchResponseData;
+}
+
 // @public
 export interface RemoteConfigParameter {
     conditionalValues?: {
@@ -205,6 +224,9 @@ export interface RemoteConfigUser {
 
 // @public
 export interface ServerConfig {
+    getAll(): {
+        [key: string]: Value;
+    };
     getBoolean(key: string): boolean;
     getNumber(key: string): number;
     getString(key: string): string;

From 805dec81e755778cbd7fdd228fcc689e69b7411b Mon Sep 17 00:00:00 2001
From: kjelko <kjelko@google.com>
Date: Fri, 3 Jan 2025 12:22:17 -0500
Subject: [PATCH 06/10] Refine api and rerun docs

---
 etc/firebase-admin.remote-config.api.md |  5 +----
 src/remote-config/remote-config-api.ts  | 25 +++++++++++++++++++----
 src/remote-config/remote-config.ts      | 27 ++++++++++++++++---------
 3 files changed, 40 insertions(+), 17 deletions(-)

diff --git a/etc/firebase-admin.remote-config.api.md b/etc/firebase-admin.remote-config.api.md
index 0d39f2b0ab..b821417506 100644
--- a/etc/firebase-admin.remote-config.api.md
+++ b/etc/firebase-admin.remote-config.api.md
@@ -54,13 +54,10 @@ export interface ExplicitParameterValue {
 
 // @public
 export interface FetchResponseData {
-    // (undocumented)
     config?: {
         [key: string]: string;
     };
-    // (undocumented)
     eTag: string;
-    // (undocumented)
     status: number;
 }
 
@@ -176,7 +173,7 @@ export interface RemoteConfigCondition {
 
 // @public
 export class RemoteConfigFetchResponse {
-    constructor(app: App, serverConfig: ServerConfig, eTag?: string);
+    constructor(app: App, serverConfig: ServerConfig, requestEtag?: string);
     // (undocumented)
     toJSON(): FetchResponseData;
 }
diff --git a/src/remote-config/remote-config-api.ts b/src/remote-config/remote-config-api.ts
index 6d83757455..fafdd42cf5 100644
--- a/src/remote-config/remote-config-api.ts
+++ b/src/remote-config/remote-config-api.ts
@@ -236,7 +236,7 @@ export enum CustomSignalOperator {
   /**
    * Matches a numeric value less than or equal to the target value.
    */
-  NUMERIC_LESS_EQUAL ='NUMERIC_LESS_EQUAL',
+  NUMERIC_LESS_EQUAL = 'NUMERIC_LESS_EQUAL',
 
   /**
    * Matches a numeric value equal to the target value.
@@ -537,7 +537,7 @@ export interface ServerTemplate {
 /**
  * Generic map of developer-defined signals used as evaluation input signals.
  */
-export type UserProvidedSignals = {[key: string]: string|number};
+export type UserProvidedSignals = { [key: string]: string | number };
 
 /**
  * Predefined template evaluation input signals.
@@ -733,7 +733,7 @@ export interface ServerConfig {
    * 
    * @returns A map of all config keys to their values.
    */
-  getAll(): {[key:string]: Value}
+  getAll(): { [key: string]: Value }
 }
 
 /**
@@ -741,9 +741,26 @@ export interface ServerConfig {
  * Remote Config web client SDKs.
  */
 export interface FetchResponseData {
+  /**
+   * The HTTP status, which is useful for differentiating success responses with data from
+   * those without.
+   * 
+   * This use of 200 and 304 response codes is consistent with Remote Config's server 
+   * implementation.
+   */
   status: number;
+
+  /**
+   * Defines the ETag response header value.
+   * 
+   * This is consistent with Remote Config's server eTag implementation.
+   */
   eTag: string;
-  config?: {[key: string]: string};
+
+  /**
+   * Defines the map of parameters returned as "entries" in the fetch response body.
+   */
+  config?: { [key: string]: string };
 }
 
 /**
diff --git a/src/remote-config/remote-config.ts b/src/remote-config/remote-config.ts
index 8a60b2cf9c..2addb1f055 100644
--- a/src/remote-config/remote-config.ts
+++ b/src/remote-config/remote-config.ts
@@ -300,7 +300,7 @@ class RemoteConfigTemplateImpl implements RemoteConfigTemplate {
  */
 class ServerTemplateImpl implements ServerTemplate {
   private cache: ServerTemplateData;
-  private stringifiedDefaultConfig: {[key: string]: string} = {};
+  private stringifiedDefaultConfig: { [key: string]: string } = {};
 
   constructor(
     private readonly apiClient: RemoteConfigApiClient,
@@ -427,7 +427,7 @@ class ServerTemplateImpl implements ServerTemplate {
 class ServerConfigImpl implements ServerConfig {
   constructor(
     private readonly configValues: { [key: string]: Value },
-  ){}
+  ) { }
   getBoolean(key: string): boolean {
     return this.getValue(key).asBoolean();
   }
@@ -440,7 +440,7 @@ class ServerConfigImpl implements ServerConfig {
   getValue(key: string): Value {
     return this.configValues[key] || new ValueImpl('static');
   }
-  getAll(): {[key: string]: Value} {
+  getAll(): { [key: string]: Value } {
     return { ...this.configValues };
   }
 }
@@ -625,18 +625,23 @@ class VersionImpl implements Version {
 export class RemoteConfigFetchResponse {
   private response: FetchResponseData;
 
-  constructor(app: App, serverConfig: ServerConfig, eTag?: string) {
-    const config: {[key:string]: string} = {};
+  /**
+   * @param app - The app for this RemoteConfig service.
+   * @param serverConfig - The server config for which to generate a fetch response.
+   * @param requestEtag - A request eTag with which to compare the current response.
+   */
+  constructor(app: App, serverConfig: ServerConfig, requestEtag?: string) {
+    const config: { [key: string]: string } = {};
     for (const [param, value] of Object.entries(serverConfig.getAll())) {
       config[param] = value.asString();
     }
 
     const currentEtag = this.processEtag(config, app);
 
-    if (currentEtag === eTag) {
+    if (currentEtag === requestEtag) {
       this.response = {
         status: 304,
-        eTag,
+        eTag: currentEtag,
       };
     } else {
       this.response = {
@@ -647,11 +652,15 @@ export class RemoteConfigFetchResponse {
     }
   }
 
-  toJSON(): FetchResponseData {
+  /** 
+   * @returns JSON representation of the fetch response that can be consumed
+   * by the RC client SDK.
+   */
+  public toJSON(): FetchResponseData {
     return this.response;
   }
 
-  private processEtag(config: {[key:string]: string}, app: App): string {
+  private processEtag(config: { [key: string]: string }, app: App): string {
     const configJson = JSON.stringify(config);
     let hash = 0;
     for (let i = 0; i < configJson.length; i++) {

From e67c529bcd472d617200fc28220dc39e5f089641 Mon Sep 17 00:00:00 2001
From: kjelko <kjelko@google.com>
Date: Fri, 3 Jan 2025 12:25:28 -0500
Subject: [PATCH 07/10] add back the newline

---
 src/remote-config/index.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/remote-config/index.ts b/src/remote-config/index.ts
index cb3383e3d3..42a2573227 100644
--- a/src/remote-config/index.ts
+++ b/src/remote-config/index.ts
@@ -96,4 +96,4 @@ export function getRemoteConfig(app?: App): RemoteConfig {
 
   const firebaseApp: FirebaseApp = app as FirebaseApp;
   return firebaseApp.getOrInitService('remoteConfig', (app) => new RemoteConfig(app));
-}
\ No newline at end of file
+}

From 8d66a9148cc191d3931702ab716767e4f7ca8298 Mon Sep 17 00:00:00 2001
From: kjelko <kjelko@google.com>
Date: Mon, 13 Jan 2025 18:41:37 -0500
Subject: [PATCH 08/10] Apply suggestions from review

---
 src/remote-config/remote-config.ts            |  8 ++++++--
 test/unit/remote-config/remote-config.spec.ts | 18 +++++++++---------
 2 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/src/remote-config/remote-config.ts b/src/remote-config/remote-config.ts
index 2addb1f055..a984d67e1f 100644
--- a/src/remote-config/remote-config.ts
+++ b/src/remote-config/remote-config.ts
@@ -619,6 +619,9 @@ class VersionImpl implements Version {
   }
 }
 
+const HTTP_NOT_MODIFIED = 304;
+const HTTP_OK = 200;
+
 /**
  * Represents a fetch response that can be used to interact with RC's client SDK.
  */
@@ -640,12 +643,12 @@ export class RemoteConfigFetchResponse {
 
     if (currentEtag === requestEtag) {
       this.response = {
-        status: 304,
+        status: HTTP_NOT_MODIFIED,
         eTag: currentEtag,
       };
     } else {
       this.response = {
-        status: 200,
+        status: HTTP_OK,
         eTag: currentEtag,
         config,
       }
@@ -663,6 +666,7 @@ export class RemoteConfigFetchResponse {
   private processEtag(config: { [key: string]: string }, app: App): string {
     const configJson = JSON.stringify(config);
     let hash = 0;
+    // Mimics Java's `String.hashCode()` which is used in RC's servers.
     for (let i = 0; i < configJson.length; i++) {
       const char = configJson.charCodeAt(i);
       hash = (hash << 5) - hash + char;
diff --git a/test/unit/remote-config/remote-config.spec.ts b/test/unit/remote-config/remote-config.spec.ts
index 3270492d5d..976266e5ab 100644
--- a/test/unit/remote-config/remote-config.spec.ts
+++ b/test/unit/remote-config/remote-config.spec.ts
@@ -1002,14 +1002,14 @@ describe('RemoteConfig', () => {
       describe('should throw error if there are any JSON or tempalte parsing errors', () => {
         const INVALID_PARAMETERS: any[] = [null, '', 'abc', 1, true, []];
         const INVALID_CONDITIONS: any[] = [null, '', 'abc', 1, true, {}];
-  
+
         let sourceTemplate = deepCopy(SERVER_REMOTE_CONFIG_RESPONSE);
         const jsonString = '{invalidJson: null}';
         it('should throw if template is an invalid JSON', () => {
           expect(() => remoteConfig.initServerTemplate({ template: jsonString }))
             .to.throw(/Failed to parse the JSON string: ([\D\w]*)\./);
         });
-  
+
         INVALID_PARAMETERS.forEach((invalidParameter) => {
           sourceTemplate.parameters = invalidParameter;
           const jsonString = JSON.stringify(sourceTemplate);
@@ -1018,7 +1018,7 @@ describe('RemoteConfig', () => {
               .to.throw('Remote Config parameters must be a non-null object');
           });
         });
-  
+
         sourceTemplate = deepCopy(SERVER_REMOTE_CONFIG_RESPONSE);
         INVALID_CONDITIONS.forEach((invalidConditions) => {
           sourceTemplate.conditions = invalidConditions;
@@ -1339,7 +1339,7 @@ describe('RemoteConfig', () => {
         expect(value.asString()).to.equal('');
         expect(value.getSource()).to.equal('static');
       });
-  
+
       it('should return default value when it is defined', () => {
         const templateData = deepCopy(SERVER_REMOTE_CONFIG_RESPONSE) as ServerTemplateData;
         // Omits remote parameter values.
@@ -1357,7 +1357,7 @@ describe('RemoteConfig', () => {
         expect(value.asString()).to.equal('shiba');
         expect(value.getSource()).to.equal('default');
       });
-  
+
       it('should return remote value when it is defined', () => {
         const templateData = deepCopy(SERVER_REMOTE_CONFIG_RESPONSE) as ServerTemplateData;
         // Defines remote parameter values.
@@ -1426,7 +1426,7 @@ describe('RemoteConfig', () => {
   });
 
   describe('RemoteConfigFetchResponse', () => {
-    it('should return a 200 response with no etag', () => {
+    it('should return a 200 response when supplied with no etag', () => {
       const templateData = deepCopy(SERVER_REMOTE_CONFIG_RESPONSE) as ServerTemplateData;
       // Defines remote parameter values.
       templateData.parameters = {
@@ -1444,8 +1444,8 @@ describe('RemoteConfig', () => {
         config: { 'dog_type': 'beagle' }
       });
     });
-  
-    it('should return a 200 response with a stale etag', () => {
+
+    it('should return a 200 response when supplied with a stale etag', () => {
       const templateData = deepCopy(SERVER_REMOTE_CONFIG_RESPONSE) as ServerTemplateData;
       // Defines remote parameter values.
       templateData.parameters = {
@@ -1463,7 +1463,7 @@ describe('RemoteConfig', () => {
         config: { 'dog_type': 'beagle' }
       });
     });
-  
+
     it('should return a 304 repsonse with matching etag', () => {
       const templateData = deepCopy(SERVER_REMOTE_CONFIG_RESPONSE) as ServerTemplateData;
       // Defines remote parameter values.

From 20082ef9b5bee81af48977bbdca51c4f31e52990 Mon Sep 17 00:00:00 2001
From: kjelko <kjelko@google.com>
Date: Tue, 11 Feb 2025 16:39:10 -0500
Subject: [PATCH 09/10] Make eTag optional in fetch response

---
 src/remote-config/remote-config-api.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/remote-config/remote-config-api.ts b/src/remote-config/remote-config-api.ts
index fafdd42cf5..d315572192 100644
--- a/src/remote-config/remote-config-api.ts
+++ b/src/remote-config/remote-config-api.ts
@@ -751,11 +751,11 @@ export interface FetchResponseData {
   status: number;
 
   /**
-   * Defines the ETag response header value.
+   * Defines the ETag response header value. Only defined for 200 and 304 responses.
    * 
    * This is consistent with Remote Config's server eTag implementation.
    */
-  eTag: string;
+  eTag?: string;
 
   /**
    * Defines the map of parameters returned as "entries" in the fetch response body.

From 3d750bf7304d78e16e62607fe419063c642be8b0 Mon Sep 17 00:00:00 2001
From: kjelko <kjelko@google.com>
Date: Tue, 11 Feb 2025 16:47:25 -0500
Subject: [PATCH 10/10] rerun doc generator

---
 etc/firebase-admin.remote-config.api.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/etc/firebase-admin.remote-config.api.md b/etc/firebase-admin.remote-config.api.md
index b821417506..cf7eb32b93 100644
--- a/etc/firebase-admin.remote-config.api.md
+++ b/etc/firebase-admin.remote-config.api.md
@@ -57,7 +57,7 @@ export interface FetchResponseData {
     config?: {
         [key: string]: string;
     };
-    eTag: string;
+    eTag?: string;
     status: number;
 }