feat(openapi3): Import OpenAPI deprecated field as #deprecated directive

[Copilot]

OpenAPI documents with deprecated: true on schemas or properties were losing this information during conversion to TypeSpec. The deprecated flag must round-trip as TypeSpec's #deprecated directive.

Changes

Core Implementation

• Added TypeSpecDirective interface and directives field to TypeSpecDeclaration and TypeSpecModelProperty
• Created getDirectivesForSchema() to extract deprecated: true from OpenAPI schemas
• Created generateDirectives() to output #deprecated "deprecated" syntax

Integration Points

• Updated schema transforms (populateEnum, populateModel, populateUnion, populateScalar) to extract directives
• Updated model property generation to include directives from schema properties
• Ensured directives render before decorators in generated TypeSpec

Example

Input OpenAPI:

components:
  schemas:
    Foo:
      type: object
      properties:
        bar:
          type: string
          deprecated: true

Output TypeSpec:

model Foo {
  #deprecated "deprecated"
  bar?: string;
}

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• telemetry.astro.build
  • Triggering command: /usr/local/bin/node node /home/REDACTED/work/typespec/typespec/website/node_modules/.bin/../astro/astro.js build /usr/local/bin/node s/.b�� sc -p ./tsconfig.build.json sh (dns block)

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Original prompt

---

This section details on the original issue you should resolve

<issue_title>[Bug]: tsp-openapi3: "deprecated" decorators not imported</issue_title>
<issue_description>### Describe the bug

OpenAPI that declares @deprecated does not result in #deprecated on import.

detected as part of the "TypeSpec for Sefaria" hack.

Reproduction

Easiest way to see is to round-trip this model:

model Foo {
  #deprecated "omit"
  bar?: string
}

TSP -> OpenAPI: Playground
Result from importing the OpenAPI output: Playground

model Foo {
  bar?: string;
}

Checklist

• Follow our Code of Conduct
• Check that there isn't already an issue that request the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion.
• The provided reproduction is a minimal reproducible example of the bug.</issue_description>

<agent_instructions>Make sure you read through the whole discussion and not just the first message.
Make sure you follow conventional commit.
This issue is a feature request not a bug.
Make sure you run the formatting command before committing.
Start by implementing unit tests for the import tool first, then fix the code.
When you're done, run npx @chronus/chronus add to add a new feature changelog entry.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

@baywet Hi @Arithmomaniac Thank you for using the SDK and for reaching out.

I'll shortly assign copilot to go implement a fix for this issue.

For completeness, here is the OpenAPI description that's being imported.

openapi: 3.0.0
info:
  title: (title)
  version: 0.0.0
tags: []
paths: {}
components:
  schemas:
    Foo:
      type: object
      properties:
        bar:
          type: string
          deprecated: true

Let us know if you have any additional comments or questions.</comment_new>

• Fixes [Bug]: tsp-openapi3: "deprecated" decorators not imported #4453

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