Class Handlers

Factory methods for standard Handler implementations.

Inheritance

System.Object

Handlers

Namespace: LaunchDarkly.TestHelpers.HttpTest

Assembly: LaunchDarkly.TestHelpers.dll

Syntax

public static class Handlers : Object

Properties

Default

A Handler that does nothing but set the status to 200. Useful as a start when chaining with Then(Handler, Handler).

Declaration

public static Handler Default { get; }

Property Value

Type	Description
Handler

Methods

AddHeader(String, String)

Creates a Handler that adds a response header, without overwriting any previous values.

Declaration

public static Handler AddHeader(string name, string value)

Parameters

Type	Name	Description
System.String	name	the header name
System.String	value	the header value

Returns

Type	Description
Handler	a Handler

See Also

Header(String, String)

AsMessageHandler(Handler)

Converts a Handler to a standard .NET System.Net.Http.HttpMessageHandler.

Declaration

public static HttpMessageHandler AsMessageHandler(this Handler handler)

Parameters

Type	Name	Description
Handler	handler	the handler to execute

Returns

Type	Description
System.Net.Http.HttpMessageHandler	an HttpMessageHandler

Remarks

This allows the various handlers in this library to be used as a convenient, composable way to simulate responses from an HttpClient using a custom HttpMessageHandler that does not make any network requests. This can be useful in testing code that makes requests to a real external URI, redirecting it to your internal fixture. It also allows simulating network errors; see Error(Exception).

Examples

    // Here we will intercept any request from the configured HttpClient so it
    // receives a 503 response, while also recording requests.
    var messageHandler = Handlers.Record(out var recorder)
        .Then(Handlers.Status(503)).AsMessageHandler();
    var httpClient = new HttpClient(messageHandler);

    // ...Do something that will cause a request to be made...

    var request = recorder.RequireRequest();
    // Verify the properties of the request that was made

Body(String, Byte[])

Creates a Handler that sends the specified response body.

Declaration

public static Handler Body(string contentType, byte[] body)

Parameters

Type	Name	Description
System.String	contentType	response content type
System.Byte[]	body	response body (null is equivalent to an empty array)

Returns

Type	Description
Handler	a Handler

See Also

BodyString(String, String, Encoding)

BodyJson(String, Encoding)

BodyJson(String, Encoding)

Creates a Handler that sends a response body with JSON content type.

Declaration

public static Handler BodyJson(string jsonBody, Encoding encoding = null)

Parameters

Type	Name	Description
System.String	jsonBody	the JSON data
System.Text.Encoding	encoding	response encoding (defaults to UTF8)

Returns

Type	Description
Handler	a Handler

See Also

Body(String, Byte[])

BodyString(String, String, Encoding)

BodyString(String, String, Encoding)

Creates a Handler that sends the specified response body.

Declaration

public static Handler BodyString(string contentType, string body, Encoding encoding = null)

Parameters

Type	Name	Description
System.String	contentType	response content type (used only if body is not null)
System.String	body	response body (may be null)
System.Text.Encoding	encoding	character encoding; if not specified, no charset will be included in the Content-Type header, but UTF8 will be used to encode the string

Returns

Type	Description
Handler	a Handler

See Also

Body(String, Byte[])

BodyJson(String, Encoding)

Delay(TimeSpan)

Creates a Handler that sleeps for the specified amount of time.

Declaration

public static Handler Delay(TimeSpan delay)

Parameters

Type	Name	Description
System.TimeSpan	delay	how long to delay

Returns

Type	Description
Handler	a Handler

Error(Exception)

Creates a Handler that throws an exception. The effect of this depends on how the handler is being used - see Remarks.

Declaration

public static Handler Error(Exception ex)

Parameters

Type	Name	Description
System.Exception	ex

Returns

Type	Description
Handler

Remarks

When used in a real end-to-end HTTP scenario with an HttpServer, this simply results in an HTTP 500 response. There is no way to simulate a network error in this framework.

However, when used with AsMessageHandler(Handler), this causes the exception to be thrown out of the HttpClient. Therefore, you can use this handler in test code that needs to simulate an I/O error from HttpClient.

Examples

    var messageHandler = Handlers.Error(new IOException("bad hostname")).AsMessageHandler();
    var httpClient = new HttpClient(messageHandler);

Hang()

Creates a Handler that sleeps indefinitely, holding the connection open, until the server is closed.

Declaration

public static Handler Hang()

Returns

Type	Description
Handler	a Handler

Header(String, String)

Creates a Handler that sets a response header.

Declaration

public static Handler Header(string name, string value)

Parameters

Type	Name	Description
System.String	name	the header name
System.String	value	the header value

Returns

Type	Description
Handler	a Handler

Examples

    var handler = Handlers.Default.Then(Handlers.Header("Etag", "123")).
        Then(Handlers.JsonBody("{}"));

See Also

AddHeader(String, String)

Record(out RequestRecorder)

Creates a RequestRecorder that captures requests.

Declaration

public static Handler Record(out RequestRecorder recorder)

Parameters

Type	Name	Description
RequestRecorder	recorder	receives the new RequestRecorder instance

Returns

Type	Description
Handler	a Handler that will pass requests to the recorder

Remarks

You won't normally need to use this directly, since the HttpServer has a RequestRecorder built in, but you could use it to capture a subset of requests.

Examples

    var handler = Handlers.Record(out var recorder).Then(Handlers.Status(200));

See Also

RequestRecorder

Router(out SimpleRouter)

Creates a SimpleRouter for delegating to other handlers based on the request path.

Declaration

public static Handler Router(out SimpleRouter router)

Parameters

Type	Name	Description
SimpleRouter	router	receives the new SimpleRouter instance

Returns

Type	Description
Handler

Examples

    var server = HttpServer.Start(Handlers.Router(out var router));
    router.AddPath("/goodpath", Handlers.Status(200));
    router.AddPath("/badpath", Handlers.Status(400));

Sequential(Handler[])

Creates a Handler that delegates to each of the specified handlers in sequence as each request is received.

Declaration

public static Handler Sequential(params Handler[] handlers)

Parameters

Type	Name	Description
Handler[]	handlers	a list of handlers

Returns

Type	Description
Handler	a Handler

Remarks

Any requests that happen after the last handler in the list has been used will receive a 500 error.

See Also

SequentialWithLastRepeating(Handler[])

SequentialWithLastRepeating(Handler[])

Creates a Handler that delegates to each of the specified handlers in sequence as each request is received.

Declaration

public static Handler SequentialWithLastRepeating(params Handler[] handlers)

Parameters

Type	Name	Description
Handler[]	handlers	a list of handlers

Returns

Type	Description
Handler	a Handler

Remarks

Any requests that happen after the last handler in the list has been used will continue to use the last handler.

See Also

Sequential(Handler[])

StartChunks(String, Encoding)

Creates a Handler that starts writing a chunked response.

Declaration

public static Handler StartChunks(string contentType, Encoding encoding = null)

Parameters

Type	Name	Description
System.String	contentType	the content type
System.Text.Encoding	encoding	character encoding to include in the Content-Type header; if not specified, Content-Type will not specify an encoding

Returns

Type	Description
Handler	a Handler

Examples

    var handler = Handlers.StartChunks("text/my-stream-data")
        .Then(Handlers.WriteChunkString("data1"))
        .Then(Handlers.WriteChunkString("data2"));

See Also

WriteChunk(Byte[])

WriteChunkString(String, Encoding)

Status(Int32)

Creates a Handler that sets the HTTP response status.

Declaration

public static Handler Status(int statusCode)

Parameters

Type	Name	Description
System.Int32	statusCode	the status code

Returns

Type	Description
Handler	a Handler

Status(HttpStatusCode)

Creates a Handler that sets the HTTP response status.

Declaration

public static Handler Status(HttpStatusCode statusCode)

Parameters

Type	Name	Description
System.Net.HttpStatusCode	statusCode	the status code

Returns

Type	Description
Handler	a Handler

Switchable(out HandlerSwitcher)

Creates a HandlerSwitcher for changing handler behavior dynamically. It is initially set to delegate to Default.

Declaration

public static Handler Switchable(out HandlerSwitcher switchable)

Parameters

Type	Name	Description
HandlerSwitcher	switchable	receives the new HandlerSwitcher instance

Returns

Type	Description
Handler	a HandlerSwitcher

Sync(Action<IRequestContext>)

Wraps a synchronous action in an asynchronous Handler.

Declaration

public static Handler Sync(Action<IRequestContext> action)

Parameters

Type	Name	Description
System.Action<IRequestContext>	action	the action to run

Returns

Type	Description
Handler	a Handler

Then(Handler, Handler)

Chains another handler to be executed immediately after this one.

Declaration

public static Handler Then(this Handler first, Handler second)

Parameters

Type	Name	Description
Handler	first	the first handler to execute
Handler	second	the next handler to execute

Returns

Type	Description
Handler	a Handler

Remarks

Changing the status code or headers after a previous handler has already written a response body will not work.

Examples

    var handler = Handlers.Delay(TimeSpan.FromSeconds(2)).Then(Handlers.Status(200));

WriteChunk(Byte[])

Creates a Handler that writes a chunk of response data.

Declaration

public static Handler WriteChunk(byte[] data)

Parameters

Type	Name	Description
System.Byte[]	data	the chunk data

Returns

Type	Description
Handler	a Handler

See Also

StartChunks(String, Encoding)

WriteChunkString(String, Encoding)

WriteChunkString(String, Encoding)

Creates a Handler that writes a chunk of response data.

Declaration

public static Handler WriteChunkString(string data, Encoding encoding = null)

Parameters

Type	Name	Description
System.String	data	the chunk data as a string
System.Text.Encoding	encoding	character encoding to use for this chunk (defaults to UTF8)

Returns

Type	Description
Handler	a Handler

See Also

StartChunks(String, Encoding)

WriteChunk(Byte[])