[PM-2282] Make feature flags type safe (#8612)

Refactors the feature flags in ConfigService to be type safe. It also moves the default value to a centralized location rather than the caller defining it. This ensures consistency across the various places they are used.

libs/angular/src/directives/if-feature.directive.spec.ts

@@ -3,7 +3,7 @@ import { ComponentFixture, TestBed } from "@angular/core/testing";
 import { By } from "@angular/platform-browser";
 import { mock, MockProxy } from "jest-mock-extended";
 
-import { FeatureFlag, FeatureFlagValue } from "@bitwarden/common/enums/feature-flag.enum";
+import { AllowedFeatureFlagTypes, FeatureFlag } from "@bitwarden/common/enums/feature-flag.enum";
 import { ConfigService } from "@bitwarden/common/platform/abstractions/config/config.service";
 import { LogService } from "@bitwarden/common/platform/abstractions/log.service";
 
@@ -41,10 +41,8 @@ describe("IfFeatureDirective", () => {
   let content: HTMLElement;
   let mockConfigService: MockProxy<ConfigService>;
 
-  const mockConfigFlagValue = (flag: FeatureFlag, flagValue: FeatureFlagValue) => {
-    mockConfigService.getFeatureFlag.mockImplementation((f, defaultValue) =>
-      flag == f ? Promise.resolve(flagValue) : Promise.resolve(defaultValue),
-    );
+  const mockConfigFlagValue = (flag: FeatureFlag, flagValue: AllowedFeatureFlagTypes) => {
+    mockConfigService.getFeatureFlag.mockImplementation((f) => Promise.resolve(flagValue as any));
   };
 
   const queryContent = (testId: string) =>

libs/angular/src/directives/if-feature.directive.ts

@@ -1,6 +1,6 @@
 import { Directive, Input, OnInit, TemplateRef, ViewContainerRef } from "@angular/core";
 
-import { FeatureFlag, FeatureFlagValue } from "@bitwarden/common/enums/feature-flag.enum";
+import { AllowedFeatureFlagTypes, FeatureFlag } from "@bitwarden/common/enums/feature-flag.enum";
 import { ConfigService } from "@bitwarden/common/platform/abstractions/config/config.service";
 import { LogService } from "@bitwarden/common/platform/abstractions/log.service";
 
@@ -23,7 +23,7 @@ export class IfFeatureDirective implements OnInit {
    * Optional value to compare against the value of the feature flag in the config service.
    * @default true
    */
-  @Input() appIfFeatureValue: FeatureFlagValue = true;
+  @Input() appIfFeatureValue: AllowedFeatureFlagTypes = true;
 
   private hasView = false;
 

libs/angular/src/platform/guard/feature-flag.guard.spec.ts

@@ -34,12 +34,12 @@ describe("canAccessFeature", () => {
         flag == testFlag ? Promise.resolve(flagValue) : Promise.resolve(defaultValue),
       );
     } else if (typeof flagValue === "string") {
-      mockConfigService.getFeatureFlag.mockImplementation((flag, defaultValue = "") =>
-        flag == testFlag ? Promise.resolve(flagValue) : Promise.resolve(defaultValue),
+      mockConfigService.getFeatureFlag.mockImplementation((flag) =>
+        flag == testFlag ? Promise.resolve(flagValue as any) : Promise.resolve(""),
       );
     } else if (typeof flagValue === "number") {
-      mockConfigService.getFeatureFlag.mockImplementation((flag, defaultValue = 0) =>
-        flag == testFlag ? Promise.resolve(flagValue) : Promise.resolve(defaultValue),
+      mockConfigService.getFeatureFlag.mockImplementation((flag) =>
+        flag == testFlag ? Promise.resolve(flagValue as any) : Promise.resolve(0),
       );
     }
 

libs/angular/src/vault/components/add-edit.component.ts

@@ -182,7 +182,6 @@ export class AddEditComponent implements OnInit, OnDestroy {
   async ngOnInit() {
     this.flexibleCollectionsV1Enabled = await this.configService.getFeatureFlag(
       FeatureFlag.FlexibleCollectionsV1,
-      false,
     );
 
     this.policyService

libs/common/src/enums/feature-flag.enum.ts

@@ -1,3 +1,8 @@
+/**
+ * Feature flags.
+ *
+ * Flags MUST be short lived and SHALL be removed once enabled.
+ */
 export enum FeatureFlag {
   BrowserFilelessImport = "browser-fileless-import",
   ItemShare = "item-share",
@@ -13,5 +18,32 @@ export enum FeatureFlag {
   EnableDeleteProvider = "AC-1218-delete-provider",
 }
 
-// Replace this with a type safe lookup of the feature flag values in PM-2282
-export type FeatureFlagValue = number | string | boolean;
+export type AllowedFeatureFlagTypes = boolean | number | string;
+
+// Helper to ensure the value is treated as a boolean.
+const FALSE = false as boolean;
+
+/**
+ * Default value for feature flags.
+ *
+ * DO NOT enable previously disabled flags, REMOVE them instead.
+ * We support true as a value as we prefer flags to "enable" not "disable".
+ */
+export const DefaultFeatureFlagValue = {
+  [FeatureFlag.BrowserFilelessImport]: FALSE,
+  [FeatureFlag.ItemShare]: FALSE,
+  [FeatureFlag.FlexibleCollectionsV1]: FALSE,
+  [FeatureFlag.VaultOnboarding]: FALSE,
+  [FeatureFlag.GeneratorToolsModernization]: FALSE,
+  [FeatureFlag.KeyRotationImprovements]: FALSE,
+  [FeatureFlag.FlexibleCollectionsMigration]: FALSE,
+  [FeatureFlag.ShowPaymentMethodWarningBanners]: FALSE,
+  [FeatureFlag.EnableConsolidatedBilling]: FALSE,
+  [FeatureFlag.AC1795_UpdatedSubscriptionStatusSection]: FALSE,
+  [FeatureFlag.UnassignedItemsBanner]: FALSE,
+  [FeatureFlag.EnableDeleteProvider]: FALSE,
+} satisfies Record<FeatureFlag, AllowedFeatureFlagTypes>;
+
+export type DefaultFeatureFlagValueType = typeof DefaultFeatureFlagValue;
+
+export type FeatureFlagValueType<Flag extends FeatureFlag> = DefaultFeatureFlagValueType[Flag];

libs/common/src/platform/abstractions/config/config.service.ts

@@ -1,7 +1,7 @@
 import { Observable } from "rxjs";
 import { SemVer } from "semver";
 
-import { FeatureFlag } from "../../../enums/feature-flag.enum";
+import { FeatureFlag, FeatureFlagValueType } from "../../../enums/feature-flag.enum";
 import { Region } from "../environment.service";
 
 import { ServerConfig } from "./server-config";
@@ -14,23 +14,15 @@ export abstract class ConfigService {
   /**
    * Retrieves the value of a feature flag for the currently active user
    * @param key The feature flag to retrieve
-   * @param defaultValue The default value to return if the feature flag is not set or the server's config is irretrievable
    * @returns An observable that emits the value of the feature flag, updates as the server config changes
    */
-  getFeatureFlag$: <T extends boolean | number | string>(
-    key: FeatureFlag,
-    defaultValue?: T,
-  ) => Observable<T>;
+  getFeatureFlag$: <Flag extends FeatureFlag>(key: Flag) => Observable<FeatureFlagValueType<Flag>>;
   /**
    * Retrieves the value of a feature flag for the currently active user
    * @param key The feature flag to retrieve
-   * @param defaultValue The default value to return if the feature flag is not set or the server's config is irretrievable
    * @returns The value of the feature flag
    */
-  getFeatureFlag: <T extends boolean | number | string>(
-    key: FeatureFlag,
-    defaultValue?: T,
-  ) => Promise<T>;
+  getFeatureFlag: <Flag extends FeatureFlag>(key: Flag) => Promise<FeatureFlagValueType<Flag>>;
   /**
    * Verifies whether the server version meets the minimum required version
    * @param minimumRequiredServerVersion The minimum version required

libs/common/src/platform/abstractions/config/server-config.ts

@@ -1,5 +1,6 @@
 import { Jsonify } from "type-fest";
 
+import { AllowedFeatureFlagTypes } from "../../../enums/feature-flag.enum";
 import {
   ServerConfigData,
   ThirdPartyServerConfigData,
@@ -14,7 +15,7 @@ export class ServerConfig {
   server?: ThirdPartyServerConfigData;
   environment?: EnvironmentServerConfigData;
   utcDate: Date;
-  featureStates: { [key: string]: string } = {};
+  featureStates: { [key: string]: AllowedFeatureFlagTypes } = {};
 
   constructor(serverConfigData: ServerConfigData) {
     this.version = serverConfigData.version;

libs/common/src/platform/models/data/server-config.data.ts

@@ -1,5 +1,6 @@
 import { Jsonify } from "type-fest";
 
+import { AllowedFeatureFlagTypes } from "../../../enums/feature-flag.enum";
 import { Region } from "../../abstractions/environment.service";
 import {
   ServerConfigResponse,
@@ -13,7 +14,7 @@ export class ServerConfigData {
   server?: ThirdPartyServerConfigData;
   environment?: EnvironmentServerConfigData;
   utcDate: string;
-  featureStates: { [key: string]: string } = {};
+  featureStates: { [key: string]: AllowedFeatureFlagTypes } = {};
 
   constructor(serverConfigResponse: Partial<ServerConfigResponse>) {
     this.version = serverConfigResponse?.version;

libs/common/src/platform/services/config/default-config.service.ts

@@ -13,7 +13,11 @@ import {
 } from "rxjs";
 import { SemVer } from "semver";
 
-import { FeatureFlag, FeatureFlagValue } from "../../../enums/feature-flag.enum";
+import {
+  DefaultFeatureFlagValue,
+  FeatureFlag,
+  FeatureFlagValueType,
+} from "../../../enums/feature-flag.enum";
 import { UserId } from "../../../types/guid";
 import { ConfigApiServiceAbstraction } from "../../abstractions/config/config-api.service.abstraction";
 import { ConfigService } from "../../abstractions/config/config.service";
@@ -89,20 +93,21 @@ export class DefaultConfigService implements ConfigService {
       map((config) => config?.environment?.cloudRegion ?? Region.US),
     );
   }
-  getFeatureFlag$<T extends FeatureFlagValue>(key: FeatureFlag, defaultValue?: T) {
+
+  getFeatureFlag$<Flag extends FeatureFlag>(key: Flag) {
     return this.serverConfig$.pipe(
       map((serverConfig) => {
         if (serverConfig?.featureStates == null || serverConfig.featureStates[key] == null) {
-          return defaultValue;
+          return DefaultFeatureFlagValue[key];
         }
 
-        return serverConfig.featureStates[key] as T;
+        return serverConfig.featureStates[key] as FeatureFlagValueType<Flag>;
       }),
     );
   }
 
-  async getFeatureFlag<T extends FeatureFlagValue>(key: FeatureFlag, defaultValue?: T) {
-    return await firstValueFrom(this.getFeatureFlag$(key, defaultValue));
+  async getFeatureFlag<Flag extends FeatureFlag>(key: Flag) {
+    return await firstValueFrom(this.getFeatureFlag$(key));
   }
 
   checkServerMeetsVersionRequirement$(minimumRequiredServerVersion: SemVer) {