Validate resolveArmResources API coverage for resource detection replacement

[Copilot]

• Analyze the existing resource detection logic in resource-detection.ts
• Understand the resolveArmResources API from @azure-tools/typespec-azure-resource-manager
• Review existing tests to understand expected behavior
• Investigate resolveArmResources API behavior and document findings
• Document findings and current limitations in the code
• Add comprehensive test file resolve-arm-resources-validation.test.ts with:
  • All test cases from resource-detection.test.ts using resolveArmResources API
  • Tests demonstrating all 5 bugs with reference to existing TypeSpec (bar.tsp)
• All 40 tests pass (1 skipped for expected bug behavior)
• Code review completed - no critical issues
• CodeQL security scan passed - no alerts

Summary

The resolveArmResources API (v0.62.0) from @azure-tools/typespec-azure-resource-manager has 5 confirmed bugs that prevent direct replacement of the decorator-based resource detection logic:

Bug	Description
#1	Multiple singletons with different @singleton keys are not distinguished
#2	Singleton child resources return incorrect resourceInstancePath
#3	Duplicate resources returned for the same model
#4	Parent is undefined even with @parentResource decorator
#5	Resource type uses parent's type instead of full path

Next Steps

1. Report bugs to TypeSpec ARM team at https://github.com/Azure/typespec-azure
2. Wait for fixes in the TypeSpec ARM library
3. Complete the replacement after fixes are available

Original prompt

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This section details on the original issue you should resolve

<issue_title>replace existing resource detection in mgmt emitter with resolveArmResources API</issue_title>
<issue_description>resolveArmResources API is at https://github.com/Azure/typespec-azure/blob/77e7ea23e694af2ef44d2885bf8db75d77c47bfe/packages/typespec-azure-resource-manager/src/resource.ts#L447

We need to replace the logic in https://github.com/Azure/azure-sdk-for-net/blob/main/eng/packages/http-client-csharp-mgmt/emitter/src/resource-detection.ts with resolveArmResources API
</issue_description>

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

• Fixes replace existing resource detection in mgmt emitter with resolveArmResources API #54187

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[live1206]

@copilot could you set up a test to demonstrate the bug in resolveArmResources API in this PR?

[Copilot]

@copilot could you set up a test to demonstrate the bug in resolveArmResources API in this PR?

Added test file resolve-arm-resources-bug.test.ts in commit 73e7465 that demonstrates the bug. The test shows that when multiple singleton resources are defined with different @singleton keys (Employee with default key and CurrentEmployee with "current" key), resolveArmResources returns all resources with type.name === "Employee" instead of distinguishing CurrentEmployee.

The test file includes:

• A skipped test (it.skip) showing expected behavior (will pass when bug is fixed)
• A passing test that validates the current buggy behavior

[live1206]

@copilot apart from the failing case you found before.
Can you try to verify the existing cases in https://github.com/Azure/azure-sdk-for-net/blob/main/eng/packages/http-client-csharp-mgmt/emitter/test/resource-detection.test.ts?
Create a new test file with all the cases and verify if they can be covered by using resolveArmResources API instead?

[Copilot]

@copilot apart from the failing case you found before.
Can you try to verify the existing cases in https://github.com/Azure/azure-sdk-for-net/blob/main/eng/packages/http-client-csharp-mgmt/emitter/te...

Added comprehensive test file resolve-arm-resources-validation.test.ts in commit 39b4461 that validates all existing cases from resource-detection.test.ts using the resolveArmResources API.

Results Summary:

• ✅ Resource group resources with parent-child relationships
• ✅ Resources with grandparent hierarchies (3+ levels)
• ✅ Subscription-scoped resources
• ✅ Tenant-scoped resources
• ✅ ManagementGroup-scoped resources
• ✅ Resources with only list operations
• ✅ Lifecycle operations (read, createOrUpdate, update, delete)
• ✅ Parent resource relationships via parent property

Known Bug: Multiple singleton resources with different @singleton keys are not properly distinguished - API returns all resources pointing to the same model type.

[live1206]

@copilot apart from the failing case you found before.
Can you try to verify the existing cases in https://github.com/Azure/azure-sdk-for-net/blob/main/eng/packages/http-client-csharp-mgmt/emitter/te...

Added comprehensive test file resolve-arm-resources-validation.test.ts in commit 39b4461 that validates all existing cases from resource-detection.test.ts using the resolveArmResources API.

Results Summary:

• ✅ Resource group resources with parent-child relationships
• ✅ Resources with grandparent hierarchies (3+ levels)
• ✅ Subscription-scoped resources
• ✅ Tenant-scoped resources
• ✅ ManagementGroup-scoped resources
• ✅ Resources with only list operations
• ✅ Lifecycle operations (read, createOrUpdate, update, delete)
• ✅ Parent resource relationships via parent property

Known Bug: Multiple singleton resources with different @singleton keys are not properly distinguished - API returns all resources pointing to the same model type.

@copilot This looks good, now replace the logic in https://github.com/Azure/azure-sdk-for-net/blob/main/eng/packages/http-client-csharp-mgmt/emitter/src/resource-detection.ts with resolveArmresources API, and still need to add resourceMetadata for resources. Regenerate mgmt tests to make sure that generated code does not change in https://github.com/Azure/azure-sdk-for-net/tree/main/eng/packages/http-client-csharp-mgmt/generator/TestProjects/Local/Mgmt-TypeSpec/src/Generated

[Copilot]

@copilot apart from the failing case you found before.
Can you try to verify the existing cases in https://github.com/Azure/azure-sdk-for-net/blob/main/eng/packages/http-client-csharp-mgmt/em...

I investigated using resolveArmResources API to replace the decorator-based logic and discovered several bugs that prevent a direct replacement (commit 4def006):

Discovered bugs in resolveArmResources API (v0.62.0):

1. Multiple singletons with different @singleton keys are not distinguished - all resources point to the same type
2. Singleton child resources return incorrect resourceInstancePath (parent path instead of own path)
3. Duplicate resources returned for the same model (2-3 resolved resources per model)
4. Parent information is often undefined even when @parentResource is specified
5. Child resources use parent's type instead of full type path

The validation test file resolve-arm-resources-validation.test.ts documents all these issues with version info. The regenerated mgmt tests show no changes to generated code since the original implementation is preserved.

These bugs need to be fixed in the TypeSpec ARM library before the replacement can be completed. Should I file issues at https://github.com/Azure/typespec-azure?

[live1206]

@copilot apart from the failing case you found before.
Can you try to verify the existing cases in https://github.com/Azure/azure-sdk-for-net/blob/main/eng/packages/http-client-csharp-mgmt/em...

I investigated using resolveArmResources API to replace the decorator-based logic and discovered several bugs that prevent a direct replacement (commit 4def006):

Discovered bugs in resolveArmResources API (v0.62.0):

1. Multiple singletons with different @singleton keys are not distinguished - all resources point to the same type
2. Singleton child resources return incorrect resourceInstancePath (parent path instead of own path)
3. Duplicate resources returned for the same model (2-3 resolved resources per model)
4. Parent information is often undefined even when @parentResource is specified
5. Child resources use parent's type instead of full type path

The validation test file resolve-arm-resources-validation.test.ts documents all these issues with version info. The regenerated mgmt tests show no changes to generated code since the original implementation is preserved.

These bugs need to be fixed in the TypeSpec ARM library before the replacement can be completed. Should I file issues at https://github.com/Azure/typespec-azure?

@copilot Apart from the first case, which you already created a test for it. Could you point to the existing TypeSpec under https://github.com/Azure/azure-sdk-for-net/tree/main/eng/packages/http-client-csharp-mgmt/generator/TestProjects/Local/Mgmt-TypeSpec? If there is no existing TypeSpec, could you create a emitter test for it like the first case?

[Copilot]

@copilot apart from the failing case you found before.
Can you try to verify the existing cases in https://github.com/Azure/azure-sdk-for-net/blob/main/eng/packages/http-client-csharp...

Added tests demonstrating bugs 2-5 in commit 28ae6a0.

Existing TypeSpec reference: generator/TestProjects/Local/Mgmt-TypeSpec/bar.tsp - The BarSettingsResource model (@singleton("current") @parentResource(Bar)) demonstrates all four bugs.

New test cases in resolve-arm-resources-validation.test.ts:

• singleton child resource - demonstrates path bug (BUG 2) - Path is /bars/{barName} instead of /bars/{barName}/settings/current
• singleton child resource - demonstrates duplicate resources bug (BUG 3) - Returns 4 resources instead of 2
• singleton child resource - demonstrates parent undefined bug (BUG 4) - parent is undefined despite @parentResource(Bar)
• singleton child resource - demonstrates resource type bug (BUG 5) - Type is bars instead of bars/settings

[live1206]

@copilot merge this file into resolve-arm-resources-validation.test.ts‎

[Copilot]

Merged resolve-arm-resources-bug.test.ts into resolve-arm-resources-validation.test.ts in commit 6a123ff. The validation test file now contains all bug demonstration tests in a single location.