Only use full namespace for API version enum when there are collisions

[Copilot]

PR #10061 unconditionally used the full namespace for API version enum names in multi-service scenarios. This produces unnecessarily verbose names when services have distinct last namespace segments. This PR changes the logic to only use the full namespace when there's an actual collision, and restores the ClientHelper.BuildNameForService helper for proper prefix/suffix-aware naming. The collision-aware naming applies to all multi-service generated members — enum type names, version property names, and latest version field names all use BuildNameForService by default, falling back to full namespace only when last segments collide. The enum type naming follows the {X}ServiceVersion pattern (e.g., KeyVaultServiceVersion) rather than Service{X}Version.

Behavior

Namespaces	Member	Before (PR #10061)	After (no collision)	After (collision)
Sample.KeyVault, Sample.Storage	Enum type	SampleKeyVaultVersion	KeyVaultServiceVersion	—
Sample.KeyVault, Sample.Storage	Version property	SampleKeyVaultApiVersion	KeyVaultApiVersion	—
Sample.KeyVault, Sample.Storage	Latest field	LatestServiceKeyVaultVersion	LatestKeyVaultVersion	—
Azure.One.Tests, Azure.Two.Tests	Enum type	AzureOneTestsVersion	—	AzureOneTestsVersion (collision on Tests)
Azure.One.Tests, Azure.Two.Tests	Version property	AzureOneTestsApiVersion	—	AzureOneTestsApiVersion (collision on Tests)

Changes

• ClientHelper.cs — restored BuildNameForService helper (removed in PR Fix duplicate API version field names for multi-service clients with colliding namespaces #10061) that extracts the last namespace segment and ensures proper prefix/suffix without duplication; added shared GetLastNamespaceSegment and HasLastSegmentCollision static helpers
• ClientHelperTests.cs — restored all 22 tests for BuildNameForService
• ApiVersionEnumProvider.BuildName() — uses ClientHelper.BuildNameForService with empty prefix and "ServiceVersion" suffix for the non-collision case, producing {X}ServiceVersion names; falls back to full namespace only when last segments collide; delegates to shared ClientHelper methods instead of local helpers
• ClientOptionsProvider.BuildVersionProperties() — uses ClientHelper.BuildNameForService for version property names in the non-collision case; falls back to full namespace only when last segments collide
• ClientOptionsProvider.BuildLatestVersionsFields() — uses ClientHelper.BuildNameForService for latest version field names in the non-collision case; falls back to full namespace only when last segments collide
• Tests — updated assertions and expected test data files (ClientOptionsProvider, ClientProvider, RestClientProvider) for member name changes in non-collision cases; added MultiServiceClient_WithCollidingLastSegments_UsesFullNamespace test and MultiServiceClient_SameLastSegment_ProducesUniqueVersionEnums test with TestData golden file validation

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Only Use Full Namespace for Api Version Enum When There are Conflicts</issue_title>
<issue_description>Follow up to #10061.

This PR introduced a change to avoid collisions in the generated api version enums in the multi-service scenario by using the full namespace of the enum as the name. We should update this to only do this whenever there is a collision in the generated names.</issue_description>

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

• Fixes Only Use Full Namespace for Api Version Enum When There are Collisions #10107

---

📱 Kick off Copilot coding agent tasks wherever you are with GitHub Mobile, available on iOS and Android.

[jorgerangel-msft]

@copilot we also need to ensure we regenerate all the test projects.

[Copilot]

@copilot we also need to ensure we regenerate all the test projects.

Ran eng/scripts/Generate.ps1 to regenerate all test projects. No files changed — all existing test projects are single-service, so the multi-service naming logic doesn't affect them. All unit tests pass (ApiVersionEnumProviderTests: 8, ClientHelperTests: 22, ClientOptionsProviderTests: 31, ClientProviderTests: 238).

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• telemetry.astro.build
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node node /home/REDACTED/work/typespec/typespec/website/node_modules/.bin/../astro/bin/astro.mjs build sh pec/�� ebsite/src/conte--llmstxt node /.bin/node --no-emit bash n/sh sh /nod�� rs && pnpm build:src node /.bin/sh build');process.node l/reference dist/node-gyp-bidoc dirname (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

[jorgerangel-msft]

@copilot lets refactor our approach here. Lets only use the naming changes from #10061 when the generated members will collide. Otherwise, lets default to the previous approach prior to the PR which was to use the client helper to create the member name.

[Copilot]

@copilot lets refactor our approach here. Lets only use the naming changes from #10061 when the generated members will collide. Otherwise, lets default to the...

Refactored to apply BuildNameForService for ALL multi-service members (enum type, version properties, field names) when there's no collision. Full namespace naming from PR #10061 is now only used as fallback when last segments collide. Updated 10 test data files and 2 test assertions, and regenerated all test projects (no changes since they're all single-service). See commit 10024bc.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• telemetry.astro.build
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node node /home/REDACTED/work/typespec/typespec/website/node_modules/.bin/../astro/bin/astro.mjs build node pec/�� tput-dir ../../w--llmstxt sh .2_tmp_5782_0/no../../website/src/content/docs/docs/emitters/openapi3/reference --no-emit ture /.bin/sh node /nod�� rs && pnpm build:src tsconfig.build.json 0/x64/lib/node_modules/npm/node_--output-dir build');process.node l/reference /.bin/node node (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

[jorgerangel-msft]

@copilot lets update the MultiServiceClient_SameLastSegment_ProducesUniqueVersionEnums test in ClientOptionsProviderTests to add TestData validation. We should not remove the existing assertions in the test

[Copilot]

@copilot lets update the MultiServiceClient_SameLastSegment_ProducesUniqueVersionEnums test in ClientOptionsProviderTests to add TestData validation. We should not remove the existing assertions in t...

Added TestData golden file validation to MultiServiceClient_SameLastSegment_ProducesUniqueVersionEnums while keeping the existing assertions. See commit e81dc12.

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/@typespec/http-client-csharp@10108

commit: 352b1da

[jorgerangel-msft]

@copilot lets change the default naming of the ServiceVersion enum in the multiservice client scenario. Instead of ServiceXVersion lets do XServiceVersion. So services Foo and Bar in a client would have members FooServiceVersion and BarServiceVersion

[Copilot]

@copilot lets change the default naming of the ServiceVersion enum in the multiservice client scenario. Instead of ServiceXVersion lets do XServiceVersion. So services Foo and Bar in a client would ha...

Changed the enum naming from Service{X}Version to {X}ServiceVersion. The BuildName() call now uses BuildNameForService(serviceNamespace, string.Empty, ApiVersionEnumName) which produces KeyVaultServiceVersion, StorageServiceVersion, etc. Updated 4 golden test data files and 2 test assertions. All 299 tests pass. See commit 352b1da.