[JoshLove-msft]

Summary

• normalize date-time Start* and End* names to StartsOn and EndsOn
• preserve exact First* and Last* date-time names while retaining compound-name normalization
• keep normalized operation parameters mapped to their original input names so header, query, and path serialization is not dropped

Addresses feedback from Azure/azure-sdk-for-net#62390.

Validation

• npm run build
• eng/scripts/Generate.ps1
• npm test
• npm run cop

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npm i https://pkg.pr.new/@typespec/http-client-csharp@11751

commit: f0597f0

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[Copilot]

Pull request overview

Updates C# date-time naming normalization and preserves serialization for renamed operation parameters.

Changes:

• Normalize Start*/End* date-time names to StartsOn/EndsOn.
• Preserve exact First*/Last* names.
• Map normalized parameters to original input names during serialization.
• Update naming, provider, constructor, and request serialization tests.

A critical collision remains unresolved: distinct inputs such as startTime and startsOn can produce the same generated name.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Summary
packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator/test/Utilities/CSharpNameExtensionsTests.cs	Tests naming normalization.
packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator/test/Providers/PropertyProviderTests.cs	Tests normalized property names.
packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator/test/Providers/ParameterProviderTests.cs	Tests normalized parameter names.
packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator/test/Providers/ModelProviders/TestData/ModelProviderTests/ConstructorParameterNormalizesDateTimeSuffix.cs	Updates generated constructor output.
packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator/test/Providers/ModelProviders/TestData/ModelProviderTests/BackCompat_ConstructorParameterPreservesDateTimeSuffix.cs	Updates compatibility output.
packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator/test/Providers/ModelProviders/ModelProviderTests.cs	Updates constructor naming expectations.
packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator/src/Shared/CSharpNameExtensions.cs	Updates date-time naming rules; collision handling remains required.
packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/test/Providers/RestClientProviders/RestClientProviderTests.cs	Tests header, query, and path serialization.
packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/src/Providers/RestClientProvider.cs	Maps original parameter names for serialization.

Suppressed comments (1)

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator/src/Shared/CSharpNameExtensions.cs:106

• This new mapping changes an existing public StartTime/EndTime date-time member from the previously emitted StartOn/EndOn to StartsOn/EndsOn. The model-property back-compat check only recognizes the raw StartTime name (PropertyProvider.cs:106-115), so a normal regeneration whose last contract contains StartOn will not preserve the shipped property name (and there is no later property-name restoration). Please preserve the last-contract member name or otherwise add an explicit compatibility path before applying this rename.

                ["End"] = "Ends",
                ["Expiration"] = "Expires",
                ["Modification"] = "Modified",
                ["Start"] = "Starts"

---

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[Copilot]

Pull request overview

Copilot reviewed 9 out of 9 changed files in this pull request and generated no new comments.

Suppressed comments (1)

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator/src/Shared/CSharpNameExtensions.cs:106

• These rewrites can make a valid operation un-generatable. For example, date-time parameter startTime and a separate parameter startsOn now both produce the requested C# name startsOn (similarly endTime/endsOn). RestClientProvider.BuildMessage then calls signature.Parameters.ToDictionary(p => p.Name, ...), which throws on the duplicate before CodeWriter can disambiguate declarations. Please resolve normalized-name collisions when constructing parameters and map serialization by the originating InputParameter rather than by the colliding string name.

                ["End"] = "Ends",
                ["Expiration"] = "Expires",
                ["Modification"] = "Modified",
                ["Start"] = "Starts"

[Copilot]

Pull request overview

Copilot reviewed 10 out of 10 changed files in this pull request and generated 2 comments.

[Copilot]

Pull request overview

Copilot reviewed 12 out of 12 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 13 out of 13 changed files in this pull request and generated no new comments.

Suppressed comments (1)

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/src/Providers/RestClientProvider.cs:1672

• For next-link requests that reinject only one of two raw names differing by case (for example, startTime but not StartTime), the reduced map contains only the first exact key, yet this fallback also resolves StartTime to that value. Since query/header emission still iterates every operation parameter, both wire parameters are then serialized from the single reinjected argument. Exact case-collision handling therefore remains incorrect for reinjected subsets; preserve knowledge of case-colliding operation names and do not use the insensitive fallback for an absent exact alias (and add a paging regression where only one casing is reinjected).

            public bool TryGetValue(string name, [NotNullWhen(true)] out ParameterProvider? parameter)
                => _exact.TryGetValue(name, out parameter) ||
                    _caseInsensitive.TryGetValue(name, out parameter);

[Copilot]

Pull request overview

Copilot reviewed 13 out of 13 changed files in this pull request and generated 1 comment.

Suppressed comments (1)

packages/http-client-csharp/generator/Microsoft.TypeSpec.Generator.ClientModel/src/Providers/RestClientProvider.cs:269

• Generated names are inserted before exact input-name aliases, so parameter order still determines correctness. For an operation ordered as startsOn (string), then startTime (date-time), both providers initially use the generated key startsOn; the second assignment overwrites the first, and the first parameter's later TryAdd("startsOn", ...) cannot restore its exact alias. Consequently both wire parameters serialize the date-time argument. The current regression uses only the favorable reverse order. Give exact InputParameter.Name aliases precedence over generated-name keys (or store them separately) so lookup is order-independent.

            foreach (var parameter in parameters)
            {
                paramMap[parameter.Name] = parameter;
            }

[Copilot]

Pull request overview

Copilot reviewed 16 out of 16 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 17 out of 17 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 18 out of 18 changed files in this pull request and generated no new comments.