## Source Generator

> **Recommendation:** Consider using [Refitter.MSBuild](https://www.nuget.org/packages/Refitter.MSBuild) instead to ensure that the code is generated pre-compile which allows the Refit source generator to work without rebuilding the project.

Refitter is available as a C# Source Generator that uses the [Refitter.Core](https://github.com/christianhelle/refitter/tree/main/src/Refitter.Core) library for generating a REST API Client using the [Refit](https://github.com/reactiveui/refit) library. Refitter can generate the Refit interface from OpenAPI specifications. Refitter could format the generated Refit interface to be managed by [Apizr](https://www.apizr.net) (v6+) and generate some registration helpers too.

The Refitter source generator creates a folder called `Generated` in the same location as the `.refitter` file and generates files to disk under the `Generated` folder (can be changed with `outputFolder`). The source generator output should be included in the project and committed to source control. This is done because there is no other way to trigger the Refit source generator to pickup the Refitter generated code

***(Translation: I couldn't for the life of me figure how to get that to work, sorry)***

### Installation

The source generator is distributed as a NuGet package and should be installed to the project that will contain the generated code

```shell
dotnet add package Refitter.SourceGenerator
dotnet add package Refit
```

`Refitter.SourceGenerator` keeps its `Refit` dependency private, so consuming projects must add their own direct package reference to `Refit`. If you use generated dependency-injection helpers such as `ConfigureRefitClients()`, also add `Refit.HttpClientFactory` explicitly.

### Usage

After installing the package, add one or more `.refitter` files to your project.

`Refitter.SourceGenerator` automatically includes `**/*.refitter` as Roslyn `AdditionalFiles` via its package props, so you do not need to add manual `<AdditionalFiles Include="..." />` entries unless you intentionally override that default behavior.

### .Refitter File format

The following is an example `.refitter` file

```js
{
  "openApiPath": "/path/to/your/openAPI", // Required if openApiPaths is not specified
  "namespace": "Org.System.Service.Api.GeneratedCode", // Optional. Default=GeneratedCode
  "contractsNamespace": "Org.System.Service.Api.GeneratedCode.Contracts", // Optional. Default=GeneratedCode
  "naming": {
    "useOpenApiTitle": false, // Optional. Default=true
    "interfaceName": "MyApiClient" // Optional. Default=ApiClient
  },
  "generateContracts": true, // Optional. Default=true
  "generateClients": true, // Optional. Default=true
  "generateXmlDocCodeComments": true, // Optional. Default=true
  "generateStatusCodeComments": true, // Optional. Default=true
  "addAutoGeneratedHeader": true, // Optional. Default=true
  "addAcceptHeaders": true, // Optional. Default=true
  "addContentTypeHeaders": true, // Optional. Default=true
  "returnIApiResponse": false, // Optional. Default=false
  "responseTypeOverride": { // Optional. Default={}
    "File_Upload": "IApiResponse",
    "File_Download": "System.Net.Http.HttpContent"
  },
  "generateOperationHeaders": true, // Optional. Default=true
  "ignoredOperationHeaders": ["apiKey"], // Optional. Default=[]
  "typeAccessibility": "Public", // Optional. Values=Public|Internal. Default=Public
  "useCancellationTokens": false, // Optional. Default=false
  "useIsoDateFormat": false, // Optional. Default=false
  "multipleInterfaces": "ByEndpoint", // Optional. May be one of "ByEndpoint" or "ByTag"
  "generateDeprecatedOperations": false, // Optional. Default=true
  "operationNameTemplate": "{operationName}Async", // Optional. Must contain {operationName}. When multipleInterfaces == "ByEndpoint", this is name of the Execute() method in the interface where all instances of the string '{operationName}' is replaced with 'Execute'
  "optionalParameters": false, // Optional. Default=false
  "outputFolder": "../CustomOutput" // Optional. Default=./Generated
  "outputFilename": "RefitInterface.cs", // Optional. Default=Output.cs for CLI tool
  "contractsOutputFolder": "../Contracts", // Optional. Default=NULL
  "generateMultipleFiles": false, // Optional. Default=false
  "additionalNamespaces": [ // Optional
    "Namespace1",
    "Namespace2"
  ],
  "excludeNamespaces": [ // Optional. Exclude namespaces that match the provided regular expressions
    "^Namespace[.].*",
    "^Namespace$"
  ],
  "includeTags": [ // Optional. OpenAPI Tag to include when generating code
    "Pet",
    "Store",
    "User"
  ],
  "includePathMatches": [ // Optional. Only include Paths that match the provided regular expression
    "^/pet/.*",
    "^/store/.*"
  ],
  "trimUnusedSchema": false, // Optional. Default=false
  "keepSchemaPatterns": [ // Optional. Force to keep matching schema, uses regular expressions. Use together with trimUnusedSchema=true
    "^Model$",
    "^Person.+"
  ],
  "includeInheritanceHierarchy": false, // Optional. Default=false. Set to true to keep all possible type-instances of inheritance/union types. This works in conjunction with trimUnusedSchema.
  "generateDefaultAdditionalProperties": true, // Optional. default=true
  "operationNameGenerator": "Default", // Optional. May be one of Default, MultipleClientsFromOperationId, MultipleClientsFromPathSegments, MultipleClientsFromFirstTagAndOperationId, MultipleClientsFromFirstTagAndOperationName, MultipleClientsFromFirstTagAndPathSegments, SingleClientFromOperationId, SingleClientFromPathSegments
  "immutableRecords": false,
  "useDynamicQuerystringParameters": true, // Optional. Default=false
  "usePolymorphicSerialization": true, // Optional. Default=false
  "generateDisposableClients": true, // Optional. Default=false
  "dependencyInjectionSettings": { // Optional
    "baseUrl": "https://petstore3.swagger.io/api/v3", // Optional. Leave this blank to set the base address manually
    "httpMessageHandlers": [ // Optional
        "AuthorizationMessageHandler",
        "TelemetryMessageHandler"
    ],
    "useWindowsAuthentication": true, // Optional. Default=false
    "transientErrorHandler": "Polly", // Optional. Value=None|Polly|HttpResilience
    "maxRetryCount": 3, // Optional. Default=6
    "firstBackoffRetryInSeconds": 0.5 // Optional. Default=1.0
  },
  "apizrSettings": { // Optional
    "withRequestOptions": true, // Optional. Default=true
    "withRegistrationHelper": true, // Optional. Default=false
    "withCacheProvider": "InMemory", // Optional. Values=None|Akavache|MonkeyCache|InMemory|DistributedAsString|DistributedAsByteArray. Default=None
    "withPriority": true, // Optional. Default=false
    "withMediation": true, // Optional. Default=false
    "withOptionalMediation": true, // Optional. Default=false
    "withMappingProvider": "AutoMapper", // Optional. Values=None|AutoMapper|Mapster. Default=None
    "withFileTransfer": true // Optional. Default=false
  },
  "codeGeneratorSettings": { // Optional. Default settings are the values set in this example
    "requiredPropertiesMustBeDefined": true,
    "generateDataAnnotations": true,
    "anyType": "object",
    "dateType": "System.DateTimeOffset",
    "dateTimeType": "System.DateTimeOffset",
    "timeType": "System.TimeSpan",
    "timeSpanType": "System.TimeSpan",
    "arrayType": "System.Collections.Generic.ICollection",
    "dictionaryType": "System.Collections.Generic.IDictionary",
    "arrayInstanceType": "System.Collections.ObjectModel.Collection",
    "dictionaryInstanceType": "System.Collections.Generic.Dictionary",
    "arrayBaseType": "System.Collections.ObjectModel.Collection",
    "dictionaryBaseType": "System.Collections.Generic.Dictionary",
    "integerType": "Int32", // Optional. Default="Int32". The .NET type for OpenAPI integers without a format. Possible values: "Int32", "Int64"
    "propertySetterAccessModifier": "",
    "generateImmutableArrayProperties": false,
    "generateImmutableDictionaryProperties": false,
    "handleReferences": false,
    "jsonSerializerSettingsTransformationMethod": null,
    "generateJsonMethods": false,
    "enforceFlagEnums": false,
    "inlineNamedDictionaries": false,
    "inlineNamedTuples": true,
    "inlineNamedArrays": false,
    "generateOptionalPropertiesAsNullable": false,
    "generateNullableReferenceTypes": false,
    "generateNativeRecords": false,
    "generateDefaultValues": true,
    "inlineNamedAny": false,
    "inlineJsonConverters": true, // Optional. Default=true. Set to false to not generate JsonConverter attributes for enum properties
    "dateFormat": "yyyy-MM-dd",
    "dateTimeFormat": "yyyy-MM-dd",
    "excludedTypeNames": [
      "ExcludedTypeFoo",
      "ExcludedTypeBar"
    ],
    "customTemplateDirectory": "./path/to/directory/" // Optional. See <https://github.com/RicoSuter/NSwag/wiki/Templates>
  }
}
```

The following is an example `.refitter` file using multiple OpenAPI specifications that are merged into a single client

```js
{
  "openApiPaths": [ // Required if openApiPath is not specified. Documents are merged; first spec wins on duplicates
    "/path/to/your/openAPI/v1",
    "/path/to/your/openAPI/v2"
  ],
  "namespace": "Org.System.Service.Api.GeneratedCode"
}
```

- `openApiPath` - points to the OpenAPI Specifications file. This can be the path to a file stored on disk, relative to the `.refitter` file. This can also be a URL to a remote file that will be downloaded over HTTP/HTTPS. Required if `openApiPaths` is not specified.
- `openApiPaths` - an array of paths to multiple OpenAPI Specifications files. When specified, the documents are merged into a single client. The first document in the array serves as the base; paths, component schemas, definitions (OpenAPI 2.x), and tags from subsequent documents are merged in. When duplicates exist (same path key or schema name), the first document's entry is preserved. Use this instead of `openApiPath` when you want to generate a single client from multiple API versions. Required if `openApiPath` is not specified.
- `namespace` - the namespace used in the generated code. If not specified, this defaults to `GeneratedCode`
- `contractsNamespace` - the namespace used for generated contracts. If not specified, this defaults to `GeneratedCode`
- `naming.useOpenApiTitle` - a boolean indicating whether the OpenApi title should be used. Default is `true`
- `naming.interfaceName` - the name of the generated interface. The generated code will automatically prefix this with `I` so if this set to `MyApiClient` then the generated interface is called `IMyApiClient`. Default is `ApiClient`
- `generateContracts` - a boolean indicating whether contracts should be generated. A use case for this is several API clients use the same contracts. Default is `true`
- `generateClients` - a boolean indicating whether clients should be generated. A use case for this is to separate clients and contracts into two separate generation runs. Default is `true`
- `generateXmlDocCodeComments` - a boolean indicating whether XML doc comments should be generated. Default is `true`
- `generateStatusCodeComments` - a boolean indicating whether the XML docs for `ApiException` and `IApiResponse` contain detailed descriptions for every documented status code. Default is `true`
- `addAutoGeneratedHeader` - a boolean indicating whether XML doc comments should be generated. Default is `true`
- `addAcceptHeaders` -  a boolean indicating whether to add accept headers [Headers("Accept: application/json")]. Default is `true`
- `addContentTypeHeaders` - a boolean indicating whether to add content type headers [Headers("Content-Type: application/json")]. Default is `true`
- `returnIApiResponse` - a boolean indicating whether to return `IApiResponse<T>` objects. Default is `false`
- `responseTypeOverride` - a dictionary with operation ids (as specified in the OpenAPI document) and a particular return type to use. The types are wrapped in a task, but otherwise unmodified (so make sure to specify or import their namespaces). Default is `{}`
- `generateOperationHeaders` - a boolean indicating whether to use operation headers in the generated methods. Default is `true`
- `ignoredOperationHeaders` - A collection of headers to omit from operation signatures. Default is `[]`
- `typeAccessibility` - the generated type accessibility. Possible values are `Public` and `Internal`. Default is `Public`
- `useCancellationTokens` - Use cancellation tokens in the generated methods. Default is `false`
- `useIsoDateFormat` - Set to `true` to explicitly format date query string parameters in ISO 8601 standard date format using delimiters (for example: 2023-06-15). Default is `false`
- `multipleInterfaces` - Set to `ByEndpoint` to generate an interface for each endpoint, or `ByTag` to group Endpoints by their Tag (like SwaggerUI groups them).
- `outputFolder` - a string describing a relative path to a desired output folder. Default is `./Generated`
- `outputFilename` - Output filename. Default is `Output.cs` when used from the CLI tool, otherwise its the .refitter filename. So `Petstore.refitter` becomes `Petstore.cs`.
- `contractsOutputFolder` - a relative contracts output folder. Default is `NULL`
- `generateMultipleFiles` - generates multiple disk files. Default is `false`
- `additionalNamespaces` - A collection of additional namespaces to include in the generated file. A use case for this is when you want to reuse contracts from a different namespace than the generated code. Default is empty
- `excludeNamespaces` - A collection of regular expressions to exclude namespaces from the generated file. A use case for this is when your project has global usings where these namespaces would be redundant. Default is empty
- `includeTags` - A collection of tags to use a filter for including endpoints that contain this tag.
- `includePathMatches` - A collection of regular expressions used to filter paths.
- `generateDeprecatedOperations` - a boolean indicating whether deprecated operations should be generated or skipped. Default is `true`
- `operationNameTemplate` - Generate operation names using pattern. This must contain the string {operationName}. An example usage of this could be `{operationName}Async` to suffix all method names with Async. When using multiple interfaces with `ByEndpoint`, this is name of the Execute() method in the interface where all instances of the string '{operationName}' is replaced with 'Execute'
- `optionalParameters` - Generate non-required parameters as nullable optional parameters
- `trimUnusedSchema` - Removes unreferenced components schema to keep the generated output to a minimum
- `keepSchemaPatterns`: A collection of regular expressions to force to keep matching schema. This is used together with `trimUnusedSchema`
- `includeInheritanceHierarchy`: Set to `true` to keep all possible type-instances of inheritance/union types. If this is `false` only directly referenced types will be kept. This works in conjunction with `trimUnusedSchema`. Default is `false`
- `generateDefaultAdditionalProperties`: Set to `false` to skip default additional properties. Default is `true`
- `operationNameGenerator`: The NSwag `IOperationNameGenerator` implementation to use. See <https://refitter.github.io/api/Refitter.Core.OperationNameGeneratorTypes.html>
- `immutableRecords`: Set to `true` to generate contracts as immutable records instead of classes. Default is `false`
- `useDynamicQuerystringParameters`: Set to `true` to wrap multiple query parameters into a single complex one. Default is `false` (no wrapping). See <https://github.com/reactiveui/refit?tab=readme-ov-file#dynamic-querystring-parameters> for more information.
- `dependencyInjectionSettings` - Setting this will generated extension methods to `IServiceCollection` for configuring Refit clients, including optional Windows Authentication support
  - `baseUrl` - Used as the HttpClient base address. Leave this blank to manually set the base URL
  - `httpMessageHandlers` - A collection of `HttpMessageHandler` that is added to the HttpClient pipeline
  - `transientErrorHandler` - This is the transient error handler to use. Possible values are `None`, `Polly`, and `HttpResilience`. Default is `None`
  - `maxRetryCount` - This is the max retry count used in the Polly retry policy. Default is 6
  - `firstBackoffRetryInSeconds` - This is the duration of the initial retry backoff. Default is 1 second
- `apizrSettings` - Setting this will format Refit interface to be managed by Apizr. See <https://www.apizr.net> for more information
  - `withRequestOptions` - Tells if the Refit interface methods should have a final IApizrRequestOptions options parameter
  - `withRegistrationHelper` - Tells if Refitter should generate Apizr registration helpers (extended with dependencyInjectionSettings set, otherwise static)
  - `withCacheProvider` - Set the cache provider to be used
  - `withPriority` - Tells if Apizr should handle request priority
  - `withMediation` - Tells if Apizr should handle request mediation (extended only)
  - `withOptionalMediation` - Tells if Apizr should handle optional request mediation (extended only)
  - `withMappingProvider` - Set the mapping provider to be used
  - `withFileTransfer` - Tells if Apizr should handle file transfer
- `codeGeneratorSettings` - Setting this allows customization of the NSwag generated types and contracts
  - `requiredPropertiesMustBeDefined` - Default is true,
  - `generateDataAnnotations` - Default is true,
  - `anyType` - Default is `object`,
  - `dateType` - Default is `System.DateTimeOffset`,
  - `dateTimeType` - Default is `System.DateTimeOffset`,
  - `timeType` - Default is `System.TimeSpan`,
  - `timeSpanType` - Default is `System.TimeSpan`,
  - `arrayType` - Default is `System.Collections.Generic.ICollection`,
  - `dictionaryType` - Default is `System.Collections.Generic.IDictionary`,
  - `arrayInstanceType` - Default is `System.Collections.ObjectModel.Collection`,
  - `dictionaryInstanceType` - Default is `System.Collections.Generic.Dictionary`,
  - `arrayBaseType` - Default is `System.Collections.ObjectModel.Collection`,
  - `dictionaryBaseType` - Default is `System.Collections.Generic.Dictionary`,
  - `integerType` - Default is `Int32`. The .NET type to use for OpenAPI integer types without a format specifier. Possible values: `Int32`, `Int64`
  - `propertySetterAccessModifier` - Default is ``,
  - `generateImmutableArrayProperties` - Default is false,
  - `generateImmutableDictionaryProperties` - Default is false,
  - `handleReferences` - Default is false,
  - `jsonSerializerSettingsTransformationMethod` - Default is null,
  - `generateJsonMethods` - Default is false,
  - `enforceFlagEnums` - Default is false,
  - `inlineNamedDictionaries` - Default is false,
  - `inlineNamedTuples` - Default is true,
  - `inlineNamedArrays` - Default is false,
  - `generateOptionalPropertiesAsNullable` - Default is false,
  - `generateNullableReferenceTypes` - Default is false,
  - `generateNativeRecords` - Default is false
  - `generateDefaultValues` - Default is true
  - `inlineNamedAny` - Default is false
  - `inlineJsonConverters` - Default is true. When set to false, enum properties will not have `[JsonConverter(typeof(JsonStringEnumConverter))]` attributes
  - `dateFormat` - Default is null
  - `dateTimeFormat` - Default is null
  - `excludedTypeNames` - Default is empty
  - `customTemplateDirectory` - Custom directory with NSwag fluid templates for code generation. Default is null which uses the default NSwag templates. See <https://github.com/RicoSuter/NSwag/wiki/Templates>
