1.0.0

TypeSpec 1.0 Release

Today, we’re thrilled to announce the general availability of TypeSpec 1.0! This milestone marks the transition of TypeSpec’s core components from release candidate to stable release status. TypeSpec is a Microsoft-built, community-supported project that makes API-first development truly practical by empowering you to define your APIs in a concise, human-readable format and generate all the artifacts you need—from OpenAPI specifications to client libraries and server code scaffolding—from a single source of truth.

See our blog post

Breaking Changes

@typespec/http

#7230 Changed @patch so that it does not apply the “implicit optionality” transform by default anymore.
```
@patch op update(@body pet: Pet): void;
```
To use JSON Merge-Patch to update resources, replace the body property with an instance of MergePatchUpdate as follows:
```
@patch op update(@body pet: MergePatchUpdate<Pet>): void;
```
Or, keep the old behavior by explicitly enabling implicitOptionality in the @patch options:
```
@patch(#{ implicitOptionality: true }) op update(@body pet: Pet): void;
```

Features

@typespec/compiler

#7199 Add “capitalize” string helper to compiler
#7180 Add support for formatting tspconfig.yaml with tsp format
#7180 tsp format only formats files it knows about and ignores other. Allowing a more generic glob pattern tsp format . or tsp format "**/*"
#5674 [LSP] Update imports when renaming typespec files
#7125 Adds typekits for getting intrinsic types via $.intrinsic.<type>
#7204 Update typekits is* methods to accept Entity instead of just Type or Value
#7108 Adds support for nesting typekits
#7202 Replaces $.model.getSpreadType with $.model.getIndexType to better reflect what it actually being returned. getSpreadType did not actually return a list of spread types, but the model’s indexer type instead.
#7090 Adds TypeKit support for type.inNamespace to check namespace membership
#7167 Adds $.value.resolve and $.type.resolve typekits, and updated $.resolve to return values or types, instead of just types
#7106 Adds $.type.isAssignableTo, $.value.isAssignableTo and $.entity.isAssignableTo typekits. Also registers $.resolve typekit
#7193 Typekits have been moved out of experimental and can now be accessed via the @typespec/compiler/typekit submodule. This also removed the $.type.getDiscriminator typekit in favor of the $.model.getDiscriminatedUnion and $.union.getDiscriminatedUnion typkits.
```
import { $ } from "@typespec/compiler/experimental/typekit";
import { $ } from "@typespec/compiler/typekit";
```
#7105 Add typekit support for creating a union from an array of children
#7207 Exposed experimental function isMutableType as unsafe_isMutableType.
#7200 Added an optional nameTemplate argument to @withVisibilityFilter, allowing the visibility filters to rename models as they are transformed. This template is applied by default in the Create, Read, Update, Delete, and Query visibility transform templates. This allows for more flexible renaming than simply using the @friendlyName decorator, as it will change the primary name of the transformed type, reducing the incidence of naming conflicts.

Cached the result of applying visibility filters to types. If the same visibility filter is applied to the same type with the same configuration, the model instance produced by the visibility filter will be object-identical. This should reduce the incidence of multiple models that are structurally equivalent in visibility filters and conflicts over the name of models.

@typespec/http

#7207 Implemented JSON Merge-Patch wrappers. This allows converting a type to a JSON Merge-Patch compatible update record using the MergePatchUpdate and MergePatchCreateOrUpdate templates.

@typespec/openapi3

#7199 Add “capitalize” string helper to compiler

typespec-vscode

#7042 send compile startTime and endTime telemetry

Bug Fixes

@typespec/compiler

#7183 Fix decorators on model properties getting wrongly called when checking the template declaration in the following cases
- inside a union expression
- under an non templated operation under a templated interface
#6938 Fixes template argument resolution when a default template parameter value is resolved by a parent container (e.g. interface) For example:
```
interface Resource<T> {
  read<U = T>(): U;
}

model Foo {
  type: "foo";
}

alias FooResource = Resource<Foo>;

op readFoo is FooResource.read;
```
The returnType for readFoo would be model Foo. Previously the returnType resolved to a TemplateParameter.
#7153 Fixes handling of nested templates in getPlausibleName
#6883 Realm handle multiple instance of compiler loaded at once
#7222 Remove version property on ServiceOptions passed to @service decorator. That handling of that option was removed in 1.0.0-rc.0 where it was previously deprecated. If wanting to specify version in an OpenAPI document use the @OpenAPI.info decorator from the @typespec/openapi library
#7155 Mark TemplateParameter type as an experimental type
#7106 Removes program.checker.isTypeAssignableTo. Use one of the following typekits instead:
- $(program).type.isAssignableTo
- $(program).value.isAssignableTo
- $(program).entity.isAssignableTo
#7207 Weakened rules around @mediaTypeHint decorator, allowing media type hints with suffixes like “application/merge-patch+json”.
#7200 Fixed an error in Model visibility filtering where the indexer of a model was ignored. This prevented the value of Array/Record instances from being transformed correctly, as they now should be.

@typespec/http

#7168 Replace optional param validation requiring use with path expansion and replace with a warning when the resulting url might have a double /