Instrument cache location

[konstantin-msft]

• Instrument cache location

[Copilot]

Pull Request Overview

Adds instrumentation of the cache location into performance events and updates tests to supply and verify this new field.

• Introduces a new cacheLocation property on PerformanceEvent and updates the API doc.
• Populates cacheLocation in BaseInteractionClient during initialization.
• Updates existing tests and adds new ones in PublicClientApplication.spec.ts to set and assert on cacheLocation.

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
lib/msal-common/src/telemetry/performance/PerformanceEvent.ts	Added optional cacheLocation field to performance events
lib/msal-common/apiReview/msal-common.api.md	Updated API review to include cacheLocation
lib/msal-browser/src/interaction_client/BaseInteractionClient.ts	Instrumented cacheLocation in performance client setup
lib/msal-browser/test/custom_auth//SignClient.spec.ts	Imported cache enums, default perf client, and set cache config
lib/msal-browser/test/app/PublicClientApplication.spec.ts	Added assertions/tests for cacheLocation instrumentation

Comments suppressed due to low confidence (3)

lib/msal-common/src/telemetry/performance/PerformanceEvent.ts:902

• The cacheLocation property is typed as a generic string, which allows invalid values. Consider using the BrowserCacheLocation enum or a union type of allowed values (e.g., 'localStorage' | 'sessionStorage') for stronger type safety.

    cacheLocation?: string;

lib/msal-browser/src/interaction_client/BaseInteractionClient.ts:85

• Accessing config.cache.cacheLocation directly can throw if cache or cacheLocation is undefined. Consider adding a null-check or default value, e.g., config.cache?.cacheLocation or providing a fallback.

    }

lib/msal-browser/test/app/PublicClientApplication.spec.ts:930

• BrowserCacheLocation is used here but not imported at the top of the file, which will cause a compilation error. Please add import { BrowserCacheLocation } from '../../../../src/utils/BrowserConstants.js';.

                    cacheLocation: BrowserCacheLocation.LocalStorage,