///

## Crear un middleware { #create-a-middleware }

Para crear un middleware usas el decorador `@app.middleware("http")` encima de una función.

La función middleware recibe:

* La `request`.
* Una función `call_next` que recibirá la `request` como parámetro.
    * Esta función pasará la `request` a la correspondiente *path operation*.

Para eso, **FastAPI** proporciona una función `jsonable_encoder()`.

## Usando el `jsonable_encoder` { #using-the-jsonable-encoder }

Imaginemos que tienes una base de datos `fake_db` que solo recibe datos compatibles con JSON.

Por ejemplo, no recibe objetos `datetime`, ya que no son compatibles con JSON.

		apiRouter.ServeHTTP(recV2, reqV2)
		// Assert the response code with the expected status.
		if recV2.Code != testCase.expectedRespStatus {
			t.Fatalf("Case %d: Expected the response status to be `%d`, but instead found `%d`", i+1, testCase.expectedRespStatus, recV2.Code)
		}
		// read the response body.
		bucketPolicyReadBuf, err = io.ReadAll(recV2.Body)
		if err != nil {

		// Call the ServeHTTP to execute the handler.
		apiRouter.ServeHTTP(recV2, reqV2)
		if recV2.Code != testCase.expectedRespStatus {
			t.Errorf("Test %d: %s: Expected the response status to be `%d`, but instead found `%d`", i+1, instanceType, testCase.expectedRespStatus, recV2.Code)
		}

		errorResponse = APIErrorResponse{}
		err = xml.Unmarshal(recV2.Body.Bytes(), &errorResponse)
		if err != nil && !testCase.shouldPass {

		// Call the ServeHTTP to execute the handler.
		apiRouter.ServeHTTP(recV2, reqV2)
		if recV2.Code != testCase.expectedRespStatus {
			t.Errorf("Test %d: %s: Expected the response status to be `%d`, but instead found `%d`", i+1, instanceType, testCase.expectedRespStatus, recV2.Code)
		}

		// read the response body.
		actualContent, err = io.ReadAll(recV2.Body)
		if err != nil {

      - coverage-combine
    runs-on: ubuntu-latest
    steps:
      - name: Dump GitHub context
        env:
          GITHUB_CONTEXT: ${{ toJson(github) }}
        run: echo "$GITHUB_CONTEXT"
      - name: Decide whether the needed jobs succeeded or failed
        uses: re-actors/alls-green@release/v1
        with:

Si no lo tiene, lo genera usando la función de utilidad en `fastapi.openapi.utils.get_openapi`.

Y esa función `get_openapi()` recibe como parámetros:

* `title`: El título de OpenAPI, mostrado en la documentación.
* `version`: La versión de tu API, por ejemplo `2.5.0`.

  test-redistribute-alls-green:  # This job does nothing and is only used for the branch protection
    if: always()
    needs:
      - test-redistribute
    runs-on: ubuntu-latest
    steps:
      - name: Decide whether the needed jobs succeeded or failed
        uses: re-actors/alls-green@release/v1
        with:

Guava, the best approach is to create an [issue][] (or comment on an existing
issue if there is one) requesting the feature and describing specific use cases
for it.

If we decide to pursue a feature request, it will go through a thorough process
of API design and review. Any code should come after this.

[APIs]: https://en.wikipedia.org/wiki/API
[issue]: https://github.com/google/guava/issues

///

### Importe as dependências { #import-the-dependencies }

Este código reside no módulo `app.routers.items`, o arquivo `app/routers/items.py`.

E precisamos obter a função de dependência do módulo `app.dependencies`, o arquivo `app/dependencies.py`.