Add support to use serialisation as mode for response models

[LanderMoerkerke]

Specify mode when generating ModelField. This adds support for calculated / read-only properties defined in Pydantic (see: Fields | Pydantic Docs).

Summary by Sourcery

Support generation of response schemas using Pydantic serialization mode so computed/read-only fields are included correctly.

New Features:

• Expose a mode parameter on create_field to select between validation and serialization schema views for Pydantic models.

Enhancements:

• Use serialization mode when building response and publish model fields so computed fields appear with proper read-only metadata in AsyncAPI schemas.

Tests:

• Add coverage ensuring computed fields on response models appear as read-only and required in generated AsyncAPI schemas while remaining absent from request models.

[sourcery-ai]

Reviewer's Guide

Add support for generating response schemas in serialization mode so Pydantic v2 computed/read-only fields appear correctly, and ensure request/params schemas still reflect only input fields.

Flow diagram for using serialization mode in response ModelField generation

flowchart LR
    EndpointHandler --> RouterOperation
    RouterOperation -->|create_field mode=validation| RequestModelField
    RouterOperation -->|create_field mode=serialization| ReplyModelField
    RouterOperation -->|create_field mode=serialization| PublishParamsField

    subgraph Utils
        create_field
    end

    RouterOperation --> create_field
    create_field -->|PYDANTIC_V2 and mode set| ModelField
    create_field -->|Pydantic v1 no mode| ModelField

    ModelField --> AsyncapiSchemaGeneration

Loading

File-Level Changes

Change	Details	Files
Allow create_field to generate ModelField objects in either validation or serialization mode, and use serialization mode for response/output models so computed fields are included in AsyncAPI schemas.	Extended create_field signature to accept a mode parameter with Literal['validation', 'serialization'] defaulting to 'validation'. When running under Pydantic v2, passed the mode keyword to ModelField creation; preserved existing behavior for Pydantic v1 by keeping the previous kwargs path. Updated routing.Request and routing.Publish route initialization to create reply/params/request fields using serialization mode for result/output and publish payload models, while keeping validation mode for incoming params where appropriate.	natsapi/utils.py natsapi/routing.py
Add regression test to verify computed fields appear in response schemas but not in request schemas when using Pydantic v2 serialization mode.	Defined User and CreateUserParams models with @computed_field full_name to exercise computed/read-only properties. Registered request and publish handlers using these models, generated the AsyncAPI schema, and asserted that the User schema includes full_name as a readOnly and required property. Asserted that the CreateUserParams request schema does not include the computed full_name property, only the actual input fields.	tests/asyncapi/test_generation.py

---

Tips and commands

Interacting with Sourcery

• Trigger a new review: Comment @sourcery-ai review on the pull request.
• Continue discussions: Reply directly to Sourcery's review comments.
• Generate a GitHub issue from a review comment: Ask Sourcery to create an
  issue from a review comment by replying to it. You can also reply to a
  review comment with @sourcery-ai issue to create an issue from it.
• Generate a pull request title: Write @sourcery-ai anywhere in the pull
  request title to generate a title at any time. You can also comment
  @sourcery-ai title on the pull request to (re-)generate the title at any time.
• Generate a pull request summary: Write @sourcery-ai summary anywhere in
  the pull request body to generate a PR summary at any time exactly where you
  want it. You can also comment @sourcery-ai summary on the pull request to
  (re-)generate the summary at any time.
• Generate reviewer's guide: Comment @sourcery-ai guide on the pull
  request to (re-)generate the reviewer's guide at any time.
• Resolve all Sourcery comments: Comment @sourcery-ai resolve on the
  pull request to resolve all Sourcery comments. Useful if you've already
  addressed all the comments and don't want to see them anymore.
• Dismiss all Sourcery reviews: Comment @sourcery-ai dismiss on the pull
  request to dismiss all existing Sourcery reviews. Especially useful if you
  want to start fresh with a new review - don't forget to comment
  @sourcery-ai review to trigger a new review!

Customizing Your Experience

Access your dashboard to:

• Enable or disable review features such as the Sourcery-generated pull request
  summary, the reviewer's guide, and others.
• Change the review language.
• Add, remove or edit custom review instructions.
• Adjust other review settings.

Getting Help

• Contact our support team for questions or feedback.
• Visit our documentation for detailed guides and information.
• Keep in touch with the Sourcery team by following us on X/Twitter, LinkedIn or GitHub.

[sourcery-ai]

Hey - I've found 2 issues

Prompt for AI Agents

Please address the comments from this code review:

## Individual Comments

### Comment 1
<location path="tests/asyncapi/test_generation.py" line_range="416" />
<code_context>
     assert schema["channels"]["natsapi.development.pub"]["publish"]["summary"] == "Pub"
+
+
+def test_computed_field_in_result_should_appear_in_response_schema():
+
+    class User(BaseModel):
</code_context>
<issue_to_address>
**issue (testing):** Guard this test so it only runs under Pydantic v2 where `@computed_field` is available and the `mode` parameter is supported.

Because this test relies on v2-only features, it will fail or be meaningless under Pydantic v1. Please either skip it when running with v1 (e.g., via a version check and `pytest.mark.skipif`) or move it into a v2-only test module so the test suite remains valid across both supported versions.
</issue_to_address>

### Comment 2
<location path="tests/asyncapi/test_generation.py" line_range="443" />
<code_context>
+    def get_user(app, params: CreateUserParams):
+        return {}
+
+    @router.publish("users.CREATED")
+    def user_created(app, user: User):
+        return {}
</code_context>
<issue_to_address>
**suggestion (testing):** Add an assertion that the `users.CREATED` publish payload schema also exposes `full_name` as readOnly.

This test only verifies the shared `User` schema and request model. It doesn’t confirm that the `users.CREATED` channel’s publish message actually uses that schema (and therefore exposes `full_name` as readOnly). Please add an assertion on `schema["channels"]["natsapi.development.v1.users.CREATED"]["publish"]["message"]["payload"]` (or the correct path) to ensure the publish payload uses the serialization view including `full_name`.
</issue_to_address>

---

Sourcery is free for open source - if you like our reviews please consider sharing them ✨

• X
• Mastodon
• LinkedIn
• Facebook

_{Help me be more useful! Please click 👍 or 👎 on each comment and I'll use the feedback to improve your reviews.}