[Repo Assist] feat: generate CLI enum types for top-level named enum schemas

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Summary

Closes #146

Named OpenAPI enum schemas (with type: string or type: integer plus enum: [...]) now produce real CLI enum ProvidedTypeDefinition types instead of plain string/int aliases. This gives callers compile-time type safety and exhaustive pattern matching on API response values.

Root cause

The DefinitionCompiler previously mapped all named schemas to their scalar CLR type (e.g. string). There was no path to emit a proper CLI enum even though the TypeProviders SDK supports ProvidedTypeDefinition with BaseType = typeof<System.Enum>.

Changes

DefinitionCompiler.fs

• Added a new match branch in compileBySchema triggered when:
  • The schema is a top-level named schema (fromByPathCompiler = true && tyName ≠ null)
  • It has type: string or type: integer with a non-empty enum array
• Generates a ProvidedTypeDefinition with BaseType = typeof<System.Enum> and SetEnumUnderlyingType(typeof<int32>)
• String enums: applies [JsonConverter(typeof<JsonStringEnumConverter>)] to the type, and [JsonPropertyName(originalValue)] to each member (for round-trip serialization of names with hyphens or other special chars)
• Integer enums: uses the numeric values from the schema as literal values
• Member names are sanitized through nicePascalName and UniqueNameGenerator.MakeUnique to ensure valid .NET identifiers
• Inline enum schemas (within properties) still map to string/int; only named $ref-able schemas upgrade to enum types

RuntimeHelpers.fs

• Added buildEnumSerializer: builds an (obj -> string) function per enum type, cached in a ConcurrentDictionary
  • String enums: looks up the [JsonPropertyName] value for each member by integer ordinal
  • Integer enums: calls Convert.ChangeType to extract the underlying integer
• toParam gains an | o when ty.IsEnum -> ... branch that dispatches to the cached serializer
• Added getJsonStringEnumConverterAttribute(): returns CustomAttributeData representing [JsonConverter(typeof<JsonStringEnumConverter>)]
• Uses Attribute.GetCustomAttribute(ty, typeof<...>) (reflection-API form) for netstandard2.0 compatibility

Trade-offs

• Breaking change for named enum schemas: properties whose schema is a $ref to a named enum schema will now have the enum type rather than string/int. This is the intended behavior but callers that relied on the raw type will need to be updated.
• Inline enum schemas (within anonymous properties) still produce string/int as before — only named, top-level schemas are upgraded.
• Null enum values in the schema (enum: [null, "active"]) are silently skipped.

Test Status

✅ Build succeeded: dotnet build tests/SwaggerProvider.Tests/SwaggerProvider.Tests.fsproj -c Release

✅ All tests pass: 344 total, 0 failed, 1 skipped (pre-existing skip)

✅ Format check: dotnet fantomas --check passed after formatting

New tests added:

• Schema.TypeMappingTests: 10 new tests — named string enum → CLI type, member names, integer values, JsonConverter/JsonPropertyName attributes, integer enums, Option<EnumType> wrapping
• RuntimeHelpersTests: 8 new tests — toParam for string enum wire values, hyphenated names, integer enum serialization, Option<EnumType> unwrapping

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[sergey-tihon]

@copilot fix tests and build

[Copilot]

@copilot fix tests and build

Fixed in a895848. The CI failures were in Swashbuckle.ReturnControllers.Tests.fs and Swashbuckle.UpdateControllers.Tests.fs — the provider tests were still passing string literals like "Absolute" / "Relative" where the type provider now generates the WebAPI.UriKind enum type. Updated all affected lines to use WebAPI.UriKind.Absolute / WebAPI.UriKind.Relative for both parameters and expected return values.

[sergey-tihon]

@copilot Add new provider tests with some custom enum with more than 2 cases

[Copilot]

Pull request overview

Updates the provider to generate real CLR/CLI enum types for top-level named OpenAPI enum schemas, and extends runtime parameter serialization to preserve enum wire values.

Changes:

• Add a DefinitionCompiler.compileBySchema branch to emit ProvidedTypeDefinition enums for top-level named string/integer schemas with non-empty enum.
• Add enum-aware serialization in RuntimeHelpers.toParam with cached per-enum serializers and a helper to emit [JsonConverter(typeof<JsonStringEnumConverter>)].
• Update and add tests to validate enum type emission, attributes, and runtime serialization behavior; adjust existing provider tests to use generated enum types.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tests/SwaggerProvider.Tests/Schema.TypeMappingTests.fs	Adds tests asserting named enum schemas compile to CLI enums with correct members/attributes and optional/required property mapping.
tests/SwaggerProvider.Tests/RuntimeHelpersTests.fs	Adds tests for toParam serialization of string/integer enums (including Option<_>).
tests/SwaggerProvider.ProviderTests/Swashbuckle.UpdateControllers.Tests.fs	Updates controller integration tests to pass/expect enum types instead of strings.
tests/SwaggerProvider.ProviderTests/Swashbuckle.ReturnControllers.Tests.fs	Updates return-type integration tests to expect enum types instead of strings.
src/SwaggerProvider.Runtime/RuntimeHelpers.fs	Adds cached enum serializers and emits JsonStringEnumConverter attribute data; extends toParam to handle enums.
src/SwaggerProvider.DesignTime/DefinitionCompiler.fs	Generates non-erased CLI enum types for top-level named enum schemas (string/integer).

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[Copilot]

@copilot Add new provider tests with some custom enum with more than 2 cases

Done in 5318b60. Added a Priority enum with 4 cases (Low, Normal, High, Critical) to the test server and created Swashbuckle.CustomEnumControllers.Tests.fs with 8 integration tests covering:

• Return single priority (GET + POST)
• Return array of all 4 priorities (GET + POST)
• Update (echo-back) single priority (GET + POST)
• Update (reverse) array of 4 priorities (GET + POST)

Also fixed a latent bug in RuntimeHelpers.toQueryParams where enum arrays fell through to obj.ToString() instead of serializing each element individually — extended the Array when guard to include t.IsEnum.

[sergey-tihon]

@copilot fix inline comments

[Copilot]

@copilot fix inline comments

Fixed in 672a8f6. Addressed all three inline review comments:

1. DefinitionCompiler.fs:529-533 (int64 underlying type): Integer enums now select typeof<int64> as the underlying type when format: int64 is specified; literals are parsed with Int64.TryParse. String enums always use int32 ordinals.

2. DefinitionCompiler.fs:575 (fail on parse error): Instead of silently falling back to a sequential ordinal, invalid integer enum values now throw failwithf "Invalid integer enum value '%s' for enum '%s'...".

3. RuntimeHelpers.fs:210-216 (enum array query params): Was already fixed in the previous commit by extending the Array when guard to include t.IsEnum.

Also added a unit test for the int64 enum case (total: 345 tests, 0 failed).

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 1 comment.

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[sergey-tihon]

@copilot resolve the merge conflicts in this pull request

[Copilot]

@copilot resolve the merge conflicts in this pull request

Resolved in 893d284. The only conflict was in RuntimeHelpers.fs — master (#410) had restructured toParam to call GetType() once at the top, while this PR had added an elif ty.IsEnum arm after the Option<T> check. The resolution preserves both: the single-GetType() structure from master and the enum serializer dispatch from this PR. All 345 tests pass.

[Copilot]

Pull request overview

Copilot reviewed 11 out of 11 changed files in this pull request and generated 5 comments.

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[sergey-tihon]

@copilot address inline comments and check that we have provider tests for all kinds of enumb (int32, int64 and string)

[Copilot]

@copilot address inline comments and check that we have provider tests for all kinds of enumb (int32, int64 and string)

Done in 111b134 and 6d2ec94.

Inline review comments addressed:

1. [JsonPropertyName] → [JsonStringEnumMemberName] (all three review threads on DefinitionCompiler.fs:542-547 and RuntimeHelpers.fs:124-147): String enum members now emit [JsonStringEnumMemberName] (the correct STJ 9+ attribute honoured by JsonStringEnumConverter). buildEnumSerializer reads [JsonStringEnumMemberName] first and falls back to [JsonPropertyName] for enums generated by older builds. Both getEnumMemberNameAttribute helper and the reflective lookup use Type.GetType(...) for netstandard2.0 compatibility.

2. Duplicate-key crash (RuntimeHelpers.fs:137-151): Replaced |> dict with a Dictionary + ContainsKey/Add loop — avoids the crash on alias values and is netstandard2.0 compatible (TryAdd is only available from .NET Standard 2.1+).

Provider tests for all three enum kinds: Added tests/SwaggerProvider.ProviderTests/Schemas/enum-types.yaml and Swagger.EnumTypes.Tests.fs with explicit [<Fact>] tests covering:

• String enum (type: string): compile-time member access, IsEnum, int32 underlying type, sanitised member names
• Int32 enum (type: integer): IsEnum, int32 underlying type, correct integer values (200/404/500)
• Int64 enum (type: integer, format: int64): IsEnum, int64 underlying type, correct integer values

All 348 unit tests pass; Fantomas format check clean.

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[Copilot]

Pull request overview

Copilot reviewed 13 out of 13 changed files in this pull request and generated 2 comments.

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