例：`pip install httpx`.

///

导入 `TestClient`.

通过传入你的**FastAPI**应用创建一个 `TestClient` 。

创建名字以 `test_` 开头的函数（这是标准的 `pytest` 约定）。

像使用 `httpx` 那样使用 `TestClient` 对象。

为你需要检查的地方用标准的Python表达式写个简单的 `assert` 语句（重申，标准的`pytest`）。

```Python hl_lines="2  12  15-18"
{!../../docs_src/app_testing/tutorial001.py!}
```

/// tip | "提示"

注意测试函数是普通的 `def`，不是 `async def`。

还有client的调用也是普通的调用，不是用 `await`。

        sb.append(dm).append(updatedTime);
        sb.append(dm).append(username);
        if (sb.length() > dm.length()) {
            sb.delete(0, dm.length());
        }
        sb.insert(0, "{").append("}");
        return sb.toString();
    }

    // ===================================================================================

import static com.google.common.math.StatsTesting.assertVerticalLinearTransformation;
import static com.google.common.truth.Truth.assertThat;
import static org.junit.Assert.assertThrows;

import junit.framework.TestCase;

/**
 * Tests for {@link LinearTransformation}.
 *
 * @author Pete Gillin
 */
public class LinearTransformationTest extends TestCase {

 * annotated by {@link TestSubtype}.
 *
 * <p>These declaration methods rely on Java static type checking to make sure what we want to
 * assert as subtypes are really subtypes according to javac. For example:
 *
 * <pre>{@code
 * class MySubtypeTests extends SubtypeTester {
 *   @TestSubtype(suppressGetSubtype = true, suppressGetSupertype = true)

import static com.google.common.math.StatsTesting.assertVerticalLinearTransformation;
import static com.google.common.truth.Truth.assertThat;
import static org.junit.Assert.assertThrows;

import junit.framework.TestCase;

/**
 * Tests for {@link LinearTransformation}.
 *
 * @author Pete Gillin
 */
public class LinearTransformationTest extends TestCase {

import static java.lang.Math.min;
import static java.nio.file.attribute.PosixFilePermission.OWNER_READ;
import static java.nio.file.attribute.PosixFilePermission.OWNER_WRITE;
import static org.junit.Assert.assertThrows;

import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.file.attribute.PosixFileAttributeView;
import java.nio.file.attribute.PosixFileAttributes;

    public String xgetLocationBase() {
        final StringBuilder sb = new StringBuilder();
        ConditionQuery query = this;
        while (true) {
            if (query.isBaseQuery()) {
                sb.insert(0, CQ_PROPERTY + ".");
                break;
            } else {
                final String foreignPropertyName = query.xgetForeignPropertyName();
                if (foreignPropertyName == null) {

    public String xgetLocationBase() {
        final StringBuilder sb = new StringBuilder();
        ConditionQuery query = this;
        while (true) {
            if (query.isBaseQuery()) {
                sb.insert(0, CQ_PROPERTY + ".");
                break;
            } else {
                final String foreignPropertyName = query.xgetForeignPropertyName();
                if (foreignPropertyName == null) {

import static com.google.common.truth.Truth.assertThat;
import static java.lang.Math.max;
import static java.lang.Math.min;
import static java.nio.charset.StandardCharsets.US_ASCII;
import static org.junit.Assert.assertArrayEquals;
import static org.junit.Assert.assertThrows;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterables;
import com.google.common.hash.Hashing;

 * annotated by {@link TestSubtype}.
 *
 * <p>These declaration methods rely on Java static type checking to make sure what we want to
 * assert as subtypes are really subtypes according to javac. For example:
 *
 * <pre>{@code
 * class MySubtypeTests extends SubtypeTester {
 *   @TestSubtype(suppressGetSubtype = true, suppressGetSupertype = true)