Extract reusable MSAL test infrastructure into Microsoft.Identity.Lab.API

[Copilot]

This pull request makes several updates to the solution and build configuration, primarily focused on removing MSAL specific test projects and introducing a new shared Microsoft.Identity.Lab.Api project. This will enable higher level SDKs to use the shared test project for both Lab Infra and for unit test mocks.

Project and Solution Structure Updates:

• Removed Microsoft.Identity.Test.LabInfrastructure and Microsoft.Identity.Test.Common projects from the LibsAndSamples.sln solution file, including their configuration and project mapping entries. [1] [2] [3]
• Added the new Microsoft.Identity.Lab.Api project to the LibsAndSamples.sln solution file, including its build configurations and mapping. [1] [2] [3]
• Updated the PerformanceTests.sln solution to replace the Microsoft.Identity.Test.Common project with Microsoft.Identity.Lab.Api, and adjusted related build configuration entries. [1] [2]

Build and Packaging Configuration:

• Updated the build pipeline (build/template-pack-and-sign-all-nugets.yaml) to sign and pack the new Microsoft.Identity.Lab.Api assembly.

Internal Visibility and Documentation:

• Changed internal visibility in InternalsVisibleTo.cs to grant access to Microsoft.Identity.Lab.Api instead of Microsoft.Identity.Test.Common.
• Improved documentation wording for cache miss test cases in docs/cache_extensibility.md.

New Code Addition:

• Added a new class AuthorityWithExpectedTenantId to the Microsoft.Identity.Lab.Api project, providing a utility for authority URI and tenant ID testing.

[Copilot]

Pull request overview

This PR consolidates shared test infrastructure (previously spread across Microsoft.Identity.Test.Common and Microsoft.Identity.Test.LabInfrastructure) into a new packable library under src/client (Microsoft.Identity.Client.TestOnly), then updates unit/integration/perf/devapp test projects to reference it. It also standardizes several test constants (e.g., placeholder credentials, s_-prefixed static fields) and wires the new package into the signing/packing pipeline.

Changes:

• Introduces src/client/Microsoft.Identity.Client.TestOnly as the new home for shared test helpers/mocks and lab infra code; updates InternalsVisibleTo accordingly.
• Updates multiple test projects and solutions to reference Microsoft.Identity.Client.TestOnly and removes direct references to older test common/lab infra projects.
• Replaces several test password usages with placeholder credentials and renames a handful of test constants (ExtraHttpHeader → s_extraHttpHeader, ClientCapabilities → s_clientCapabilities, iOS constants casing, etc.).

Reviewed changes

Copilot reviewed 86 out of 101 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tests/Microsoft.Identity.Test.Unit/TelemetryTests/HttpTelemetryTests.cs	Switches ROPC password usage to placeholder credential constant.
tests/Microsoft.Identity.Test.Unit/PublicApiTests/TestIdentityLogger.cs	Removes old test logger (moved into TestOnly helpers).
tests/Microsoft.Identity.Test.Unit/PublicApiTests/PublicClientApplicationTests.cs	Updates extra header constant usage (now s_extraHttpHeader).
tests/Microsoft.Identity.Test.Unit/PublicApiTests/ConfidentialClientApplicationTests.cs	Updates client capabilities constant usage (now s_clientCapabilities).
tests/Microsoft.Identity.Test.Unit/PublicApiTests/ClientCredentialWithCertTest.cs	Replaces cert password + ROPC password constants with placeholder credentials.
tests/Microsoft.Identity.Test.Unit/PublicApiTests/ClientAssertionTests.cs	Updates client capabilities constant usage (now s_clientCapabilities).
tests/Microsoft.Identity.Test.Unit/PublicApiTests/AdfsAcceptanceTests.cs	Switches ROPC password usage to placeholder credential constant.
tests/Microsoft.Identity.Test.Unit/Microsoft.Identity.Test.Unit.csproj	Replaces project reference to old test common with new TestOnly project reference.
tests/Microsoft.Identity.Test.Unit/ManagedIdentityTests/ServiceFabricTests.cs	Updates test certificate password constant usage.
tests/Microsoft.Identity.Test.Unit/ManagedIdentityTests/ManagedIdentityTests.cs	Removes blank lines + updates client capabilities constant usage.
tests/Microsoft.Identity.Test.Unit/ManagedIdentityTests/ImdsV2Tests.cs	Removes reference to old PublicApiTests namespace import.
tests/Microsoft.Identity.Test.Unit/CryptographyTests.cs	Updates test certificate password constant usage.
tests/Microsoft.Identity.Test.Unit/CoreTests/OAuth2Tests/ClaimsTest.cs	Updates client capabilities constant usage (now s_clientCapabilities).
tests/Microsoft.Identity.Test.Unit/BrokerTests/BrokerRequestTests.cs	Renames iOS broker constant identifiers to IOS... casing.
tests/Microsoft.Identity.Test.Unit/AppConfigTests/ConfidentialClientApplicationExtensibilityApiTests.cs	Updates test certificate password constant usage.
tests/Microsoft.Identity.Test.Unit/AppConfigTests/ConfidentialClientApplicationBuilderTests.cs	Updates test certificate password + client capabilities constant usage.
tests/Microsoft.Identity.Test.Performance/Microsoft.Identity.Test.Performance.csproj	Replaces project reference to old test common with new TestOnly project reference.
tests/Microsoft.Identity.Test.LabInfrastructure/UserConfig.cs	Removes old lab infra type (moved into TestOnly).
tests/Microsoft.Identity.Test.LabInfrastructure/Microsoft.Identity.Test.LabInfrastructure.csproj	Removes old lab infra project (replaced by TestOnly).
tests/Microsoft.Identity.Test.LabInfrastructure/LabConstants.cs	Removes old lab infra constants (moved into TestOnly).
tests/Microsoft.Identity.Test.LabInfrastructure/KeyVaultSecretsProvider.cs	Removes old Key Vault provider implementation (moved into TestOnly).
tests/Microsoft.Identity.Test.LabInfrastructure/KeyVaultSecrets.cs	Removes old Key Vault secret name constants (moved into TestOnly).
tests/Microsoft.Identity.Test.LabInfrastructure/CertificateHelper.cs	Removes old cert helper (moved into TestOnly).
tests/Microsoft.Identity.Test.LabInfrastructure/AppConfig.cs	Removes old app config model (moved into TestOnly).
tests/Microsoft.Identity.Test.Integration.netfx/Microsoft.Identity.Test.Integration.NetFx.csproj	Replaces references to old lab infra/test common with TestOnly.
tests/Microsoft.Identity.Test.Integration.netcore/SeleniumTests/ConfidentialClientAuthorizationTests.cs	Updates extra header constant usage (now s_extraHttpHeader).
tests/Microsoft.Identity.Test.Integration.netcore/Microsoft.Identity.Test.Integration.NetCore.csproj	Replaces references to old lab infra/test common with TestOnly.
tests/Microsoft.Identity.Test.E2e/Microsoft.Identity.Test.E2E.MSI.csproj	Replaces reference to old test common with TestOnly.
tests/Microsoft.Identity.Test.Common/TestCategories.cs	Removes old test categories (moved into TestOnly).
tests/Microsoft.Identity.Test.Common/Core/Mocks/TestTimeService.cs	Removes old mock time service (moved into TestOnly).
tests/Microsoft.Identity.Test.Common/Core/Mocks/TestLegacyCachePersistance.cs	Removes old legacy cache persistence mock (moved into TestOnly).
tests/Microsoft.Identity.Test.Common/Core/Mocks/MockHttpManager.cs	Removes old mock HTTP manager implementation (moved into TestOnly).
tests/Microsoft.Identity.Test.Common/Core/Helpers/TokenCacheAccessRecorder.cs	Removes old cache access recorder (moved into TestOnly).
tests/Microsoft.Identity.Test.Common/Core/Helpers/RunOnPlatformAttribute.cs	Removes old platform test attributes (moved into TestOnly).
tests/Microsoft.Identity.Test.Common/Core/Helpers/RSACertificatePopCryptoProvider.cs	Removes old RSA PoP crypto provider (moved into TestOnly).
tests/Microsoft.Identity.Test.Common/Core/Helpers/RecordingHandler.cs	Removes old recording handler (moved into TestOnly).
tests/Microsoft.Identity.Test.Common/Core/Helpers/RandomDataUtils.cs	Removes old random data helper (moved into TestOnly).
tests/Microsoft.Identity.Test.Common/Core/Helpers/JsonTestUtils.cs	Removes old JSON helpers (moved into TestOnly).
tests/Microsoft.Identity.Test.Common/Core/Helpers/ECDCertificatePopCryptoProvider.cs	Removes old ECDSA PoP crypto provider (moved into TestOnly).
tests/Microsoft.Identity.Test.Common/AuthorityWithExpectedTenantId.cs	Removes old authority/tenant test model (moved into TestOnly).
tests/devapps/DesktopTestApp/DesktopTestApp.csproj	Replaces references to old test common/lab infra with TestOnly.
tests/CacheCompat/CommonCache.Test.Unit/CommonCache.Test.Unit.csproj	Replaces lab infra reference with TestOnly.
src/client/Microsoft.Identity.Client/Properties/InternalsVisibleTo.cs	Switches internals visibility from Microsoft.Identity.Test.Common to Microsoft.Identity.Client.TestOnly.
src/client/Microsoft.Identity.Client.TestOnly/UI/MsalMockHelpers.cs	Adds service bundle extension methods to configure mocked Web UI.
src/client/Microsoft.Identity.Client.TestOnly/UI/MockWebUI.cs	Adds mocked Web UI implementation for auth flows.
src/client/Microsoft.Identity.Client.TestOnly/TestData.cs	Updates client capabilities data source to use s_clientCapabilities.
src/client/Microsoft.Identity.Client.TestOnly/TestCategories.cs	Adds test category constants into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/PublicAPI.Shipped.txt	Adds initial shipped API tracking file for TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/Microsoft.Identity.Client.TestOnly.csproj	Makes TestOnly project packable; adds references and content (CredScan suppressions).
src/client/Microsoft.Identity.Client.TestOnly/LabInfra/UserConfig.cs	Adds lab user config model into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/LabInfra/LabResponseHelper.cs	Enhances docs; includes Key Vault secret retrieval helpers and caches.
src/client/Microsoft.Identity.Client.TestOnly/LabInfra/LabConstants.cs	Adds lab constants + Cloud enum into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/LabInfra/LabAuthenticationHelper.cs	Adds/updates lab auth helper docs and token acquisition helpers.
src/client/Microsoft.Identity.Client.TestOnly/LabInfra/KeyVaultSecretsProvider.cs	Adds Key Vault secret/cert provider into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/LabInfra/KeyVaultSecrets.cs	Adds Key Vault secret name constants into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/LabInfra/data.txt	Carries lab infra data file into TestOnly structure.
src/client/Microsoft.Identity.Client.TestOnly/LabInfra/CertificateHelper.cs	Adds cross-platform cert lookup/loading helper into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/LabInfra/AppConfig.cs	Adds lab app config model into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/InternalsVisibleTo.cs	Normalizes file header/formatting.
src/client/Microsoft.Identity.Client.TestOnly/Internal/TestCommon.cs	Reflows formatting/whitespace for TestCommon helper.
src/client/Microsoft.Identity.Client.TestOnly/Http/TokenCacheHelper.cs	Adds cache population helpers into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/Http/TestTimeService.cs	Adds test time service into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/Http/TestLegacyCachePersistance.cs	Adds legacy cache persistence mock into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/Http/TestGuidQueueFactory.cs	Adds deterministic GUID queue factory for tests.
src/client/Microsoft.Identity.Client.TestOnly/Http/TestGuidFactory.cs	Adds deterministic single GUID factory for tests.
src/client/Microsoft.Identity.Client.TestOnly/Http/MockHttpMessageHandler.cs	Makes mock HTTP handler public + adds extensive XML docs.
src/client/Microsoft.Identity.Client.TestOnly/Http/MockHttpManagerExtensions.cs	Updates enum docs/formatting for token response types.
src/client/Microsoft.Identity.Client.TestOnly/Http/MockHttpManager.cs	Adds mock IHttpManager and client factories into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/Http/MockHttpAndServiceBundle.cs	Adds combined HTTP manager + service bundle test harness.
src/client/Microsoft.Identity.Client.TestOnly/Http/LegacyTokenCacheHelper.cs	Adds helpers to populate ADAL legacy cache for tests.
src/client/Microsoft.Identity.Client.TestOnly/Http/InMemoryTokenCache.cs	Adds XML docs to in-memory token cache binding helpers.
src/client/Microsoft.Identity.Client.TestOnly/Http/InMemoryPartitionedTokenCache.cs	Adds in-memory partitioned token cache implementation.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/UserAccessorWithPartitionAsserts.cs	Adds partition key assertion accessor for user cache.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/TraceLogger.cs	Adds ILoggerAdapter implementation writing to Trace.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/TokenCacheExtensions.cs	Adds token cache extension helpers (record access, clear tokens).
src/client/Microsoft.Identity.Client.TestOnly/Helpers/TokenCacheAccessRecorder.cs	Adds token cache access recorder helper into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/TestIdentityLogger.cs	Adds test identity logger into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/RunOnPlatformAttribute.cs	Adds platform-based MSTest attributes into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/RSACertificatePopCryptoProvider.cs	Adds RSA PoP crypto provider helper into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/RecordingHandler.cs	Adds delegating handler to record HTTP interactions in tests.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/RandomDataUtils.cs	Adds random byte generation utility into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/PerformanceValidator.cs	Adds XML docs for timing validator utility.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/OsHelper.cs	Changes visibility + adds conditional import for NET8+; expands docs.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/ManagedIdentityTestUtil.cs	Adds extensive docs; fixes param doc mismatch.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/JsonTestUtils.cs	Adds JSON helpers into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/HttpSnifferClientFactory.cs	Adds docs for request/response recording factory and mTLS support.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/EnvVariableContext.cs	Adds docs for env var snapshot/restore helper.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/ECDCertificatePopCryptoProvider.cs	Adds ECDSA PoP crypto provider helper into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/CoreAssert.cs	Adds/updates assertion helpers; includes reflection-based immutability checker.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/AssertException.cs	Adds extensive docs to exception assertion helpers.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/AppConfigTestExtensions.cs	Adds builder extension to enable cache partitioning asserts.
src/client/Microsoft.Identity.Client.TestOnly/Helpers/AppAccessorWithPartitionAsserts.cs	Adds partition key assertion accessor for app cache.
src/client/Microsoft.Identity.Client.TestOnly/AuthorityWithExpectedTenantId.cs	Adds authority/tenant test model into TestOnly package.
src/client/Microsoft.Identity.Client.TestOnly/.config/CredScanSuppressions.json	Adds CredScan suppression for placeholder credentials in PublicAPI files.
PerformanceTests.sln	Updates solution to include TestOnly project (and remove old Test.Common).
docs/cache_extensibility.md	Minor wording clarification (“capital” → “uppercase”).
build/template-pack-and-sign-all-nugets.yaml	Adds packing/signing step for Microsoft.Identity.Client.TestOnly.

Comments suppressed due to low confidence (2)

src/client/Microsoft.Identity.Client.TestOnly/Helpers/CoreAssert.cs:143

• This helper uses reflection (Type.GetFields / BindingFlags) while living under /src. Repo guidelines discourage reflection in /src code; if this must remain, consider relocating it to the test projects instead of the packaged TestOnly library, or document/centralize the exception (and ensure it won't be used by production builds).
  src/client/Microsoft.Identity.Client.TestOnly/LabInfra/LabResponseHelper.cs:160
• The XML doc says password caching is intentionally not implemented for security reasons, but the method immediately includes a TODO to implement caching. This is contradictory and makes intended behavior unclear. Either remove the TODO or update the doc comment to reflect the actual intended approach (e.g., allow in-memory caching for test runs with appropriate caveats).

---

You can also share your feedback on Copilot code review. Take the survey.

[bgavrilMS]

Let's try to reuse the lab API package?