Arm migration docs and template enhancements (#176)

Fixes for 
- [ ] Azure/typespec-azure-pr#3842
- [ ] #88
- [ ] Azure/typespec-azure-pr#3466

.changeset/wicked-students-compare.md

@@ -0,0 +1,8 @@
+---
+"@azure-tools/typespec-azure-resource-manager": patch
+"@azure-tools/typespec-autorest": patch
+"@azure-tools/typespec-samples": patch
+"@azure-tools/typespec-azure-website": patch
+---
+
+Update references to ARM, Add template customization parameters, add migration docs

.gitignore

@@ -202,3 +202,6 @@ packages/samples/test/output/azure/templates-contoso/setup.*
 .idea/
 
 docs/**/js-api/
+
+# vitest temporary files
+**/vitest.config.ts.timestamp*

docs/emitters/typespec-autorest/reference/decorators.md

@@ -31,7 +31,7 @@ toc_max_heading_level: 3
 
 ### `@useRef` {#@Autorest.useRef}
 
-`@useRef` - is used to replace the TypeSpec model type in emitter output with a pre-existing named OpenAPI schema such as ARM common types.
+`@useRef` - is used to replace the TypeSpec model type in emitter output with a pre-existing named OpenAPI schema such as Azure Resource Manager common types.
 
 `@useRef` can be specified on Models and ModelProperty.
 

docs/howtos/migrate-swagger/migrate-arm-tips.md

@@ -0,0 +1,228 @@
+# Migrate ARM Specs
+
+The Swagger Converter will not be able to accurately represent every part of every API in TypeSpec. This document
+outlines some common changes you might need to make to a converted TypeSpec to make it conform to your existing service API and  
+pass check-in validations.
+
+## Resolving Swagger Breaking Change Violations
+
+### Changing the Names of Request Payload Parameters
+
+For operations with non-empty request bodies (PUT, POST, PATCH), the TypeSpec operation templates provide a default name for the
+request parameter corresponding to the request payload. You can use augment decorators to make changes to this parameter, and other parts of the operation signature.
+
+The following sections show how to do this for each operation template.
+
+#### CreateOrUpdate (PUT) APIs
+
+Given a PUT operation, for example:
+
+```tsp
+interface Widgets {
+  createOrUpdate is ArmResourceCreateOrReplaceAsync<Widget>;
+}
+```
+
+The name of the request body parameter is `resource` so you can change the name in clients using an augment decorator
+
+```tsp
+@@projectedName(Widgets.createOrUpdate::parameters.resource,
+  "client",
+  "<desired-request-body-parameter-name>"
+);
+```
+
+Note that this works for _any_ PUT operation template.
+
+#### Update (PATCH) APIs
+
+Given a PATCH operation, for example:
+
+```tsp
+interface Widgets {
+  update is ArmResourcePatchAsync<Widget, WidgetProperties>;
+}
+```
+
+The name of the request body parameter is `properties` so you can change the name in clients using an augment decorator
+
+```tsp
+@@projectedName(Widgets.update::parameters.properties,
+  "client",
+  "<desired-request-body-parameter-name>"
+);
+```
+
+Note that this works for _any_ PATCH operation template.
+
+### Action (POST) APIs
+
+Given a POST operation, for example:
+
+```tsp
+interface Widgets {
+  mungeWidget is ArmResourceActionAsync<Widget, MungeRequest, MungeResponse>;
+}
+```
+
+The name of the request body parameter is `body` so you can change the name in clients using an augment decorator
+
+```tsp
+@@projectedName(Widgets.mungeWidget::parameters.body,
+  "client",
+  "<desired-request-body-parameter-name>"
+);
+```
+
+Note that this works for _any_ POST operation template.
+
+### Adding Request Query or Header Parameters
+
+The `Parameters` template parameter allows you to specify additional parameters after the operation path (for example, query and header parameters) in the form of a model, with each model property corresponding to a parameter. You may use intersection to combine multiple separate parameters.
+
+```tsp
+// all list query params
+listBySubscription is ArmListBySubscription<Widget, Parameters = Azure.Core.StandardListQueryParameters>;
+
+// intersecting individual parameters
+listBySubscription is ArmListBySubscription<Widget, Parameters =  Azure.Core.TopQueryParameter & Azure.Core.SkipQueryParameter>;
+```
+
+### Changing Response Types
+
+The `Response` parameter allows you to specify non-error responses to the operation.
+
+```tsp
+// all list query params
+listBySubscription is ArmListBySubscription<Widget, Response = MyCustomCollectionType>;
+```
+
+### Changing Error Types
+
+The `Error` parameter allows you to change the default error type used in an operation.
+
+```tsp
+// all list query params
+listBySubscription is ArmListBySubscription<Widget, Error = MyCustomError>;
+```
+
+### Converting Synchronous Operations to LROs
+
+You can generally choose an asynchronous operation template that matches your operation.
+
+#### Templates for Async PUT Operations
+
+- `ArmCreateOrReplaceAsync` is a PUT operation that uses the 'resource' definition in the request body, and return a `200` response and a `201` response, both of which contain the created/updated resource in the response payload. The 201 response contains 'Location` LRO header.
+
+  ```tsp
+  createOrUpdate is ArmCreateOrReplaceAsync<Resource>;
+  ```
+
+- `ArmCreateOrUpdateAsync`is a PUT operation that uses the 'resource' definition in the request body, and return a `200` response and a `201` response, both of which contain the created/updated resource in the response payload. The 201 response contains 'Azure-AsyncOperation` LRO header.
+
+  ```tsp
+  createOrUpdate is ArmCreateOrUpdateAsync<Resource>;
+  ```
+
+#### Templates for Async PATCH Operations
+
+- `ArmTagsPatchAsync` is a PATCH operation that only allows changing the resource tags (the minimum for Azure Resource Manager).
+
+  ```tsp
+  update is ArmTagsPatchAsync<Resource>;
+  ```
+
+- `ArmResourcePatchAsync`is a PATCH operation that uses the visibility settings to select properties for the PATCH request body(any property with no visibility setting, or including visibility "update"). It follows the required 202 pattern to resolve the LRO via location, although this can be customized using the `LroHeaders` parameter.
+
+  ```tsp
+  update is ArmResourcePatchAsync<Resource, ResourceProperties>;
+  ```
+
+- `ArmCustomPatchAsync`is a PATCH operation that allows you to customize the PATCH request body.
+
+  ```tsp
+  update is ArmCustomPatchAsync<Resource, PatchRequestBody>;
+  ```
+
+#### Templates for Async POST (Action) Operations
+
+- `ArmResourceActionAsync` is a POST operation that allows you to specify the request and response body for a resource action operation. It follows the required 202 pattern to resolve the LRO via location, although this can be customized using the `LroHeaders` parameter.
+
+  ```tsp
+  doStuff is ArmResourceActionAsync<Resource, ActionRequest, ActionResponse>;
+
+  // with no request body
+  doStuffNoRequest is ArmResourceActionAsync<Resource, void, ActionResponse>;
+
+  // with no response body
+  doStuffCommand is ArmResourceActionAsync<Resource, ActionRequest, void>;
+  ```
+
+#### Templates for Async DELETE Operations
+
+- `ArmResourceDeleteWithoutOKAsync` is a DELETE operation that uses no request body, will return a `202` response in the case of an Asynchronous delete operation, and a `204` response in case the resource does not exist.
+
+  ```tsp
+  delete is ArmResourceDeleteWithoutOKAsync<Resource>;
+  ```
+
+- `ArmResourceDeleteAsync`iis a DELETE operation that uses no request body, and return a `200` response in the case of a successful synchronous delete, a `202` response in the case of an Asynchronous delete operation, and a `204` response in case the resource does not exist.
+
+  ```tsp
+  createOrUpdate is ArmResourceDeleteAsync<Resource>;
+  ```
+
+## Resolving Swagger LintDiff Violations
+
+### `VisibilityChanged` for `nextLink` and `value` properties
+
+The issue is that some older specifications marked these values as read only. This has no real impact on the API or client generation, but it is easy to mitigate for the whole specification. To fix, simply add the following augment decorator statements to the `main.tsp` file.
+
+```tsp
+@@visibility(Azure.Core.Page.value, "read");
+@@visibility(Azure.Core.Page.nextLink, "read");
+```
+
+### `ProvisioningStateMustBeReadOnly`
+
+This violation is caused by a problem with the mechanism that ARM Api validation uses to determine if a [property is read-only. You can work around the issue by setting the `use-read-only-status-schema` configuration setting in `azure/tools/typespec-autorest` options to `true` in your `tspConfig.yaml` configuration file:
+
+```yml
+emit:
+  - "@azure-tools/typespec-autorest"
+options:
+  "@azure-tools/typespec-autorest":
+    use-read-only-status-schema: true
+```
+
+### `LroLocationHeader`
+
+This violation occurs when your spec uses an LRO operation template that follows the older version of LRO standards. Tof fix the issue, you would change the operation template to match the latest recommendation.
+
+#### PUT Operations
+
+```tsp
+  // LRO PUT template with required headers and no 200 response
+  createOrUpdate is ArmResourceCreateOrReplaceAsync<MyResource>;
+```
+
+#### PATCH Operations
+
+```tsp
+  // LRO PATCH template with required headers, response codes, and lro options
+  update is ArmResourcePatchAsync<MyResource, MyResourceProperties>;
+```
+
+### POST(Action) Operations
+
+```tsp
+  // LRO POST (Action) template with required headers, response codes, and lro options
+  doAction is ArmResourceActionAsync<MyResource, RequestModel, ResponseModel>;
+```
+
+### DELETE Operations
+
+```tsp
+  // LRO delete template with required headers and no 200 response
+  delete is ArmResourceDeleteWithoutOKAsync<MyResource>;
+```