### Motivation

This library makes it easy to test that your app Does The Right Thing when it
makes HTTP and HTTPS calls. It lets you specify which responses to return and
then verify that requests were made as expected.

Because it exercises your full HTTP stack, you can be confident that you're
testing everything. You can even copy & paste HTTP responses from your real web

## Über Versionen

Gemäß den Konventionen zur semantischen Versionierung könnte jede Version unter `1.0.0` potenziell nicht abwärtskompatible Änderungen hinzufügen.

FastAPI folgt auch der Konvention, dass jede „PATCH“-Versionsänderung für Bugfixes und abwärtskompatible Änderungen gedacht ist.

!!! tip "Tipp"

 * when responses are of an unexpected type or cannot be decoded.
 *
 * Other exception types cancel the current call:
 *
 *  * For synchronous calls made with [Call.execute], the exception is propagated to the caller.
 *
 *  * For asynchronous calls made with [Call.enqueue], an [IOException] is propagated to the caller
 *    indicating that the call was canceled. The interceptor's exception is delivered to the current

Das kann beispielsweise nützlich sein, um benutzerdefinierte Header oder Cookies zurückzugeben.

## Eine `Response` zurückgeben

Tatsächlich können Sie jede `Response` oder jede Unterklasse davon zurückgeben.

!!! tip "Tipp"
    `JSONResponse` selbst ist eine Unterklasse von `Response`.

Und wenn Sie eine `Response` zurückgeben, wird **FastAPI** diese direkt weiterleiten.

## Zusätzliche Response mit `model`

Sie können Ihren *Pfadoperation-Dekoratoren* einen Parameter `responses` übergeben.

Der nimmt ein `dict` entgegen, die Schlüssel sind Statuscodes für jede Response, wie etwa `200`, und die Werte sind andere `dict`s mit den Informationen für jede Response.

Jedes dieser Response-`dict`s kann einen Schlüssel `model` haben, welcher ein Pydantic-Modell enthält, genau wie `response_model`.

  /**
   * TODO description.
   *
   * No further calls to this listener will be made.
   */
  open fun onClosed(eventSource: EventSource) {
  }

  /**
   * Invoked when an event source has been closed due to an error reading from or writing to the
   * network. Incoming events may have been lost. No further calls to this listener will be made.
   */
  open fun onFailure(
    eventSource: EventSource,
    t: Throwable?,

## Architecture decision records (ADRs)

The Gradle team uses ADRs to record architectural decisions that the team has made.

See [Architecture decisions records](standards) for the list of ADRs.

   */
  open fun onClosed(
    webSocket: WebSocket,
    code: Int,
    reason: String,
  ) {
  }

  /**
   * Invoked when a web socket has been closed due to an error reading from or writing to the
   * network. Both outgoing and incoming messages may have been lost. No further calls to this
   * listener will be made.
   */
  open fun onFailure(

        checkBinaryCompatibleKotlin(
            v1 = existingSource,
            v2 = internalSource
        ).assertEmptyReport()
    }

    @Test
    fun `existing internal members made public appear as added`() {

        checkNotBinaryCompatibleKotlin(
            v1 = internalSource,
            v2 = publicSource
        ).apply {
            assertHasErrors(

We use *Specification* and *Discovery* documents stored in Google Drive, but they present some downsides:

* They are rarely updated after creation and initial review, and then become hard to follow, especially after important decisions are made
* They are not synced with the code to reflect the eventual solution that is committed
* Google Docs is not a "code-oriented" tool, like asciidoc can be
* Review in Google Docs is not as simple as a PR code review in GitHub