// Read is never called with an empty buffer.
type testNonEmptyReader struct{ io.Reader }

func (r testNonEmptyReader) Read(b []byte) (int, error) {
	if len(b) == 0 {
		return 0, errors.New("unexpected empty Read call")
	}
	return r.Reader.Read(b)
}

func TestFileReader(t *testing.T) {
	type (
		testRead struct { // Read(cnt) == (wantStr, wantErr)
			cnt     int

     * ServerMessageBlock would have to perform the same read
     * operation on the input stream, we might as will pull that
     * common functionality into the superclass and read wordCount
     * and byteCount worth of data.
     * 
     * We will still use the readXxxWireFormat return values to
     * indicate how many bytes(note: readParameterWordsWireFormat
     * returns bytes read and not the number of words(but the

// Run a function containing a MatMul op and check its output.
// If heavy_load_on_streaming_rpc is true, send some rpc requests before the one
// which creates a remote input, to simulate a scenario that the remote input
// is not ready when we start running an op or a function.
void TestRemoteExecuteSilentCopies(bool async, bool remote, bool func,
                                   bool heavy_load_on_streaming_rpc,

# 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
```

# Templating - `Jinja2Templates`

You can use the `Jinja2Templates` class to render Jinja templates.

Read more about it in the [FastAPI docs for Templates](https://fastapi.tiangolo.com/advanced/templates/).

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

```python
from fastapi.templating import Jinja2Templates
```

type diskHealthWrapper struct {
	tracker *healthDiskCtxValue
	r       io.Reader
	w       io.Writer
}

func (d *diskHealthWrapper) Read(p []byte) (int, error) {
	if d.r == nil {
		return 0, fmt.Errorf("diskHealthWrapper: Read with no reader")
	}
	n, err := d.r.Read(p)
	if err == nil || err == io.EOF && n > 0 {
		d.tracker.logSuccess()
	}
	return n, err
}

```

::: fastapi.UploadFile
    options:
        members:
            - file
            - filename
            - size
            - headers
            - content_type
            - read
            - write
            - seek

/**
 * Result of a project build call.
 *
 * @since 4.0.0
 */
@Experimental
public interface ModelBuilderResult {

    /**
     * Gets the source from which the model was read.
     *
     * @return The source from which the model was read, never {@code null}.
     */
    @Nonnull
    ModelSource getSource();

    /**
     * Gets the file model.
     *
     * @return the file model, never {@code null}.
     */

///

## Other middlewares

You can later read more about other middlewares in the [Advanced User Guide: Advanced Middleware](../advanced/middleware.md){.internal-link target=_blank}.

    hashed_password: str


pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")

oauth2_scheme = OAuth2PasswordBearer(
    tokenUrl="token",
    scopes={"me": "Read information about the current user.", "items": "Read items."},
)

app = FastAPI()


def verify_password(plain_password, hashed_password):
    return pwd_context.verify(plain_password, hashed_password)