# Test Client - `TestClient`

You can use the `TestClient` class to test FastAPI applications without creating an actual HTTP and socket connection, just communicating directly with the FastAPI code.

Read more about it in the [FastAPI docs for Testing](https://fastapi.tiangolo.com/tutorial/testing/).

You can import it directly from `fastapi.testclient`:

```python
from fastapi.testclient import TestClient
```

import okio.Source
import okio.buffer
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.extension.RegisterExtension

class CompressionInterceptorTest {
  @RegisterExtension
  val clientTestRule = OkHttpClientTestRule()

  val source =
    Buffer().apply {
      write("Hello World".encodeUtf8())
    } as Source

  @Test
  fun emptyDoesntChangeRequestOrResponse() {

     * a <abbr>JAR</abbr> containing test classes, a POM file, <i>etc.</i>
     */
    @Nonnull
    Type getType();

    /**
     * {@return the time at which the dependency will be used}
     * It may be, for example, at compile time only, at run time, or at test time.
     */
    @Nonnull
    DependencyScope getScope();

    /**

import org.apache.maven.cling.invoker.mvn.MavenParser;
import org.codehaus.plexus.classworlds.ClassWorld;
import org.junit.jupiter.api.Disabled;
import org.junit.jupiter.api.Order;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.io.CleanupMode;
import org.junit.jupiter.api.io.TempDir;

/**
 * Resident UT.
 */
@Order(100)
public class ResidentMavenInvokerTest extends MavenInvokerTestSupport {

        object : TestListener {
            override fun beforeTest(test: TestDescriptor) = Unit
            override fun afterTest(test: TestDescriptor, result: TestResult) = Unit
            override fun beforeSuite(suite: TestDescriptor) {
                if (suite.parent == null) {
                    forEachJavaProcess { pid, _ ->
                        // processes that exist before the test suite execution should

  testApi(libs.assertk)
  testImplementation(kotlin("test"))
}

configure<AnimalSnifferExtension> {
  isIgnoreFailures = true
}

tasks.jar {
  manifest {
    attributes("Automatic-Module-Name" to "okhttp3.curl")
    attributes("Main-Class" to "okhttp3.curl.MainCommandLineKt")
  }
}

tasks.shadowJar {
  mergeServiceFiles()
}

tasks.withType<Test> {
  onlyIf("native build requires Java 17") {

import com.google.common.collect.testing.features.MapFeature;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.jspecify.annotations.NullUnmarked;

/**
 * Unit test for {@link ImmutableTypeToInstanceMap}.
 *
 * @author Ben Yu
 */
@NullUnmarked
public class ImmutableTypeToInstanceMapTest extends TestCase {

import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import junit.framework.TestCase;
import org.jspecify.annotations.Nullable;

/**
 * Abstract test case parent for anything implementing {@link ListenableFuture}. Tests the two get
 * methods and the addListener method.
 *
 * @author Sven Mawson
 * @since 10.0
 */
@GwtIncompatible

import org.codehaus.plexus.testing.PlexusTest;
import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

/**
 */
@PlexusTest
class DefaultLifecyclesTest {
    @Inject
    private DefaultLifecycles defaultLifeCycles;

    @Test
    void testDefaultLifecycles() {

    <modelVersion>4.0.0</modelVersion>

    <groupId>test</groupId>
    <artifactId>import</artifactId>
    <version>0.1-SNAPSHOT</version>
    <packaging>pom</packaging>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>test</groupId>
                <artifactId>mydep</artifactId>
                <version>0.1</version>