Fix GetTokenAcquirer to propagate MicrosoftEntraApplicationOptions properties

[Copilot]

Plan to Fix GetTokenAcquirer Option Propagation Issue ✅ COMPLETE

Understanding the Issue

The class hierarchy is:

• IdentityApplicationOptions (base class)
• MicrosoftEntraApplicationOptions extends IdentityApplicationOptions (adds: Name, Instance, TenantId, AppHomeTenantId, AzureRegion, ClientCapabilities, SendX5C)
• MicrosoftIdentityApplicationOptions extends MicrosoftEntraApplicationOptions (adds B2C properties)

In DefaultTokenAcquirerFactoryImplementation.GetTokenAcquirer(IdentityApplicationOptions), when the parameter is MicrosoftEntraApplicationOptions (but not MicrosoftIdentityApplicationOptions), the method only copies base IdentityApplicationOptions properties and misses the MicrosoftEntraApplicationOptions specific properties.

Tasks

• Understand the existing code structure and class hierarchy
• Identify the exact location where properties need to be copied
• Implement the fix to propagate MicrosoftEntraApplicationOptions properties
• Review and identify existing tests for DefaultTokenAcquirerFactoryImplementation
• Create or update tests to validate the fix
• Build and test the changes (682 tests passed)
• Run broader test suite to ensure no regressions
• Run code review (No issues found)
• Run security scan (CodeQL timed out - typical for large repos, no security concerns in our minimal changes)
• Address code review feedback: Rename variables to camelCase and copy Authority property

Summary of Changes

1. DefaultTokenAcquirerFactoryImplementation.cs (Updated)

• ✅ Renamed MicrosoftIdentityApplicationOptions variable to microsoftIdentityApplicationOptions (camelCase)
• ✅ Renamed MicrosoftEntraApplicationOptions variable to microsoftEntraApplicationOptions (camelCase)
• ✅ Added copying of Authority property from microsoftEntraApplicationOptions
• All property assignments from the intermediate class in the hierarchy:
  • Authority (newly added)
  • Name
  • Instance
  • TenantId
  • AppHomeTenantId
  • AzureRegion
  • ClientCapabilities
  • SendX5C

2. DefaultTokenAcquirerFactoryImplementationTests.cs

Created comprehensive unit tests to validate:

• ✅ MicrosoftEntraApplicationOptions properties are properly propagated
• ✅ IdentityApplicationOptions base properties continue to work
• ✅ MicrosoftIdentityApplicationOptions instances are used as-is without modification

All tests pass successfully! (682 tests passed)

Original prompt

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This section details on the original issue you should resolve

<issue_title>GetTokenAcquirer(IdentityApplicationOptions IdentityApplicationOptions) doesn't propagate all options</issue_title>
<issue_description>### Microsoft.Identity.Web Library

Microsoft.Identity.Web

Microsoft.Identity.Web version

4.1.1

Web app

Not Applicable

Web API

Not Applicable

Token cache serialization

Not Applicable

Description

MicrosoftIdentityApplicationOptions extends MicrosoftEntraApplicationOptions which extends IdentityApplicationOptions.

microsoft-identity-web/src/Microsoft.Identity.Web.TokenAcquisition/DefaultTokenAcquirerFactoryImplementation.cs

Line 57 in d050622

public ITokenAcquirer GetTokenAcquirer(IdentityApplicationOptions IdentityApplicationOptions)

In DefaultTokenAcquirerFactoryImplementation, GetTokenAcquirer(IdentityApplicationOptions IdentityApplicationOptions) doesn't propagate some options if IdentityApplicationOptions is of type MicrosoftEntraApplicationOptions

Reproduction steps

• Create an instance of MicrosoftEntraApplicationOptions and set class-specific options.
• Pass it to GetTokenAcquirer(IdentityApplicationOptions IdentityApplicationOptions)
• Check that the resulting merged options have the previously set option values.

Error message

No response

Id Web logs

No response

Relevant code snippets

n/a

Regression

No response

Expected behavior

In DefaultTokenAcquirerFactoryImplementation, GetTokenAcquirer(IdentityApplicationOptions IdentityApplicationOptions), if IdentityApplicationOptions is not MicrosoftIdentityApplicationOptions and is of MicrosoftEntraApplicationOptions type, after creating a new MicrosoftIdentityApplicationOptions instance and copying over the options from IdentityApplicationOptions, if IdentityApplicationOptions is of type MicrosoftEntraApplicationOptions, copy over those options too.

Update/add any relevant tests.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes GetTokenAcquirer(IdentityApplicationOptions IdentityApplicationOptions) doesn't propagate all options #3650

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[jmprieur]

Great catch!