feat: add conformance to product (#85)

## What I'm changing

- Closes ##83

## How I did it

We're not populating it, but we at least have an endpoint

## Checklist

- [x] Tests pass: `uv run pytest`
- [x] Checks pass: `uv run pre-commit --all-files`
- [x] CHANGELOG is updated (if necessary)

Author: gadomski

stapi-fastapi/CHANGELOG.md

@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ## Added
 
 - Add constants for route names to be used in link href generation
+- Conformance url to product ([#85](https://github.com/stapi-spec/pystapi/pull/85))
 
 ## Changed
 

stapi-fastapi/src/stapi_fastapi/routers/product_router.py

@@ -18,6 +18,7 @@
 from returns.maybe import Maybe, Some
 from returns.result import Failure, Success
 from stapi_pydantic import (
+    Conformance,
     JsonSchemaModel,
     Link,
     OpportunityCollection,
@@ -37,6 +38,7 @@
 from stapi_fastapi.models.product import Product
 from stapi_fastapi.responses import GeoJSONResponse
 from stapi_fastapi.routers.route_names import (
+    CONFORMANCE,
     CREATE_ORDER,
     GET_CONSTRAINTS,
     GET_OPPORTUNITY_COLLECTION,
@@ -91,6 +93,15 @@ def __init__(
             tags=["Products"],
         )
 
+        self.add_api_route(
+            path="/conformance",
+            endpoint=self.get_product_conformance,
+            name=f"{self.root_router.name}:{self.product.id}:{CONFORMANCE}",
+            methods=["GET"],
+            summary="Get conformance urls for the product",
+            tags=["Products"],
+        )
+
         self.add_api_route(
             path="/constraints",
             endpoint=self.get_product_constraints,
@@ -182,6 +193,15 @@ def get_product(self, request: Request) -> ProductPydantic:
                 rel="self",
                 type=TYPE_JSON,
             ),
+            Link(
+                href=str(
+                    request.url_for(
+                        f"{self.root_router.name}:{self.product.id}:{CONFORMANCE}",
+                    ),
+                ),
+                rel="conformance",
+                type=TYPE_JSON,
+            ),
             Link(
                 href=str(
                     request.url_for(
@@ -333,6 +353,12 @@ async def search_opportunities_async(
             case x:
                 raise AssertionError(f"Expected code to be unreachable: {x}")
 
+    def get_product_conformance(self) -> Conformance:
+        """
+        Return conformance urls of a specific product
+        """
+        return Conformance.model_validate({"conforms_to": self.product.conformsTo})
+
     def get_product_constraints(self) -> JsonSchemaModel:
         """
         Return supported constraints of a specific product

stapi-fastapi/tests/test_product.py

@@ -2,6 +2,7 @@
 from fastapi import status
 from fastapi.testclient import TestClient
 from stapi_fastapi.models.product import Product
+from stapi_pydantic import Conformance
 
 from .shared import pagination_tester
 
@@ -19,7 +20,7 @@ def test_products_response(stapi_client: TestClient):
 
 
 @pytest.mark.parametrize("product_id", ["test-spotlight"])
-def test_product_response_self_link(
+def test_product_response_links(
     product_id: str,
     stapi_client: TestClient,
     assert_link,
@@ -32,12 +33,28 @@ def test_product_response_self_link(
 
     url = "GET /products"
     assert_link(url, body, "self", f"/products/{product_id}")
+    assert_link(
+        url, body, "conformance", f"/products/{product_id}/conformance"
+    )  # https://github.com/stapi-spec/stapi-spec/issues/253
     assert_link(url, body, "constraints", f"/products/{product_id}/constraints")
     assert_link(url, body, "order-parameters", f"/products/{product_id}/order-parameters")
     assert_link(url, body, "opportunities", f"/products/{product_id}/opportunities")
     assert_link(url, body, "create-order", f"/products/{product_id}/orders", method="POST")
 
 
+@pytest.mark.parametrize("product_id", ["test-spotlight"])
+def test_product_conformance_response(
+    product_id: str,
+    stapi_client: TestClient,
+):
+    res = stapi_client.get(f"/products/{product_id}/constraints")
+    assert res.status_code == status.HTTP_200_OK
+    assert res.headers["Content-Type"] == "application/json"
+
+    Conformance.model_validate(res.json())
+    # TODO unsure what conformance products should support, as of yet
+
+
 @pytest.mark.parametrize("product_id", ["test-spotlight"])
 def test_product_constraints_response(
     product_id: str,
@@ -83,6 +100,11 @@ def test_get_products_pagination(
                     "rel": "self",
                     "type": "application/json",
                 },
+                {
+                    "href": f"http://stapiserver/products/{product_id}/conformance",
+                    "rel": "conformance",
+                    "type": "application/json",
+                },
                 {
                     "href": f"http://stapiserver/products/{product_id}/constraints",
                     "rel": "constraints",