Use the `TestClient` object the same way as you do with `httpx`.

Write simple `assert` statements with the standard Python expressions that you need to check (again, standard `pytest`).

{* ../../docs_src/app_testing/tutorial001.py hl[2,12,15:18] *}

/// tip

Notice that the testing functions are normal `def`, not `async def`.

    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <!--
    Some tests need reflective access to the internals of these packages. It is only the
    tests themselves and not the code being tested that needs that access, though there's no
    obvious way to ensure that.

    We could consider arranging things so that only the tests we know need this would get
    the add-opens. Right now that doesn't seem worth the effort, though.
    -->

    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <!--
    Some tests need reflective access to the internals of these packages. It is only the
    tests themselves and not the code being tested that needs that access, though there's no
    obvious way to ensure that.

    We could consider arranging things so that only the tests we know need this would get
    the add-opens. Right now that doesn't seem worth the effort, though.
    -->

	}
	// For forward compatibility reasons, we need to add this code.
	if len(dataUsageInfo.BucketsUsage) == 0 {
		dataUsageInfo.BucketsUsage = make(map[string]BucketUsageInfo, len(dataUsageInfo.BucketSizes))
		for bucket, size := range dataUsageInfo.BucketSizes {
			dataUsageInfo.BucketsUsage[bucket] = BucketUsageInfo{Size: size}
		}
	}

	// For backward compatibility reasons, we need to add this code.

        // Directory leasing requires SMB 3.0 or higher
        // MS-SMB2: Level 2 leasing (which includes directory leasing) is only supported in SMB 3.0+
        // We'll validate this when we actually need to use the session

        // Request base lease
        Smb2LeaseKey leaseKey = baseLeaseManager.requestLease(directoryPath, requestedState);

        // Create directory cache entry

    *   Both seeded and unseeded initializers will always generate the same
        values every time they are called (for a given variable shape). For
        unseeded initializers (`seed=None`), a random seed will be created and
        assigned at initializer creation (different initializer instances get
        different seeds).
    *   An unseeded initializer will raise a warning if it is reused (called)

      handleAllCompleted();
      return;
    }

    // NOTE: If we ever want to use a custom executor here, have a look at CombinedFuture as we'll
    // need to handle RejectedExecutionException

    if (allMustSucceed) {
      // We need fail fast, so we have to keep track of which future failed so we can propagate
      // the exception immediately

### Short { #short }

It has sensible **defaults** for everything, with optional configurations everywhere. All the parameters can be fine-tuned to do what you need and to define the API you need.

But by default, it all **"just works"**.

### Validation { #validation }

* Validation for most (or all?) Python **data types**, including:
    * JSON objects (`dict`).

# Response - Change Status Code { #response-change-status-code }

You probably read before that you can set a default [Response Status Code](../tutorial/response-status-code.md){.internal-link target=_blank}.

But in some cases you need to return a different status code than the default.

## Use case { #use-case }

For example, imagine that you want to return an HTTP status code of "OK" `200` by default.

            // Mock send method
            public void send(final Object postcard) {
                // Mock implementation
            }
        };

        // Mock Postbox - no need to mock, the framework will handle it

        // Register components
        ComponentUtil.register(searchEngineClient, "searchEngineClient");
        ComponentUtil.register(systemHelper, "systemHelper");