{!../../docs_src/app_testing/tutorial002.py!}
```

/// note

For more details, check Starlette's documentation for <a href="https://www.starlette.io/testclient/#testing-websocket-sessions" class="external-link" target="_blank">testing WebSockets</a>.

Dans les versions précédentes de Javascript NodeJS / Navigateur, vous auriez utilisé des "callbacks". Menant potentiellement à ce que l'on appelle <a href="http://callbackhell.com/" class="external-link" target="_blank">le "callback hell"</a>.


## Coroutines

import static java.lang.annotation.RetentionPolicy.RUNTIME;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Annotates a "top-level" type-variable usage that takes its nullness from the type argument
 * supplied by the user of the class. For example, {@code Multiset.Entry.getElement()} returns

import static java.lang.annotation.RetentionPolicy.RUNTIME;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Annotates a "top-level" type-variable usage that takes its nullness from the type argument
 * supplied by the user of the class. For example, {@code Multiset.Entry.getElement()} returns

import static java.lang.annotation.RetentionPolicy.RUNTIME;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Annotates a "top-level" type-variable usage that takes its nullness from the type argument
 * supplied by the user of the class. For example, {@code Multiset.Entry.getElement()} returns

import static java.lang.annotation.RetentionPolicy.RUNTIME;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Annotates a "top-level" type-variable usage that takes its nullness from the type argument
 * supplied by the user of the class. For example, {@code Multiset.Entry.getElement()} returns

import static java.lang.annotation.RetentionPolicy.RUNTIME;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Annotates a "top-level" type-variable usage that takes its nullness from the type argument
 * supplied by the user of the class. For example, {@code Multiset.Entry.getElement()} returns

import static java.lang.annotation.RetentionPolicy.RUNTIME;

import com.google.common.annotations.GwtCompatible;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

/**
 * Annotates a "top-level" type-variable usage that takes its nullness from the type argument
 * supplied by the user of the class. For example, {@code Multiset.Entry.getElement()} returns

        workingOnly = false,
        getOnly = false,
      )
    runBatch(dnsProviders, names)
    val dnsCache =
      Cache(
        directory = File("./target/TestDohMain.cache.${System.currentTimeMillis()}"),
        maxSize = 10L * 1024 * 1024,
      )
    println("Bad targets\n***********\n")
    val url = "https://dns.cloudflare.com/.not-so-well-known/run-dmc-query".toHttpUrl()
    val badProviders =
      listOf(

{!../../docs_src/app_testing/tutorial002.py!}
```

/// note | "Hinweis"

Weitere Informationen finden Sie in der Starlette-Dokumentation zum <a href="https://www.starlette.io/testclient/#testing-websocket-sessions" class="external-link" target="_blank">Testen von WebSockets</a>.