Snap.Test

The Snap.Test module contains primitives and combinators for testing Snap applications.

Combinators and types for testing Snap handlers.

Types

data RequestBuilder m a

RequestBuilder is a monad transformer that allows you to conveniently build a snap Request for testing.

Instances

MonadTrans RequestBuilder

Defined in Snap.Internal.Test.RequestBuilder

Methods

lift :: Monad m => m a -> RequestBuilder m a

Monad m => MonadState Request (RequestBuilder m)

Defined in Snap.Internal.Test.RequestBuilder

Methods

get :: RequestBuilder m Request

put :: Request -> RequestBuilder m ()

state :: (Request -> (a, Request)) -> RequestBuilder m a

MonadFail m => MonadFail (RequestBuilder m)

Defined in Snap.Internal.Test.RequestBuilder

Methods

fail :: String -> RequestBuilder m a

MonadIO m => MonadIO (RequestBuilder m)

Defined in Snap.Internal.Test.RequestBuilder

Methods

liftIO :: IO a -> RequestBuilder m a

Monad m => Applicative (RequestBuilder m)

Defined in Snap.Internal.Test.RequestBuilder

Methods

pure :: a -> RequestBuilder m a

(<*>) :: RequestBuilder m (a -> b) -> RequestBuilder m a -> RequestBuilder m b

liftA2 :: (a -> b -> c) -> RequestBuilder m a -> RequestBuilder m b -> RequestBuilder m c

(*>) :: RequestBuilder m a -> RequestBuilder m b -> RequestBuilder m b

(<*) :: RequestBuilder m a -> RequestBuilder m b -> RequestBuilder m a

Functor m => Functor (RequestBuilder m)

Defined in Snap.Internal.Test.RequestBuilder

Methods

fmap :: (a -> b) -> RequestBuilder m a -> RequestBuilder m b

(<$) :: a -> RequestBuilder m b -> RequestBuilder m a

Monad m => Monad (RequestBuilder m)

Defined in Snap.Internal.Test.RequestBuilder

Methods

(>>=) :: RequestBuilder m a -> (a -> RequestBuilder m b) -> RequestBuilder m b

(>>) :: RequestBuilder m a -> RequestBuilder m b -> RequestBuilder m b

return :: a -> RequestBuilder m a

type MultipartParams = [(ByteString, MultipartParam)]

A request body of type "multipart/form-data" consists of a set of named form parameters, each of which can by either a list of regular form values or a set of file uploads.

data MultipartParam

A single "multipart/form-data" form parameter: either a list of regular form values or a set of file uploads.

Constructors

FormData [ByteString]

a form variable consisting of the given ByteString values.

Files [FileData]

a file upload consisting of the given FileData values.

Instances

Show MultipartParam

Defined in Snap.Internal.Test.RequestBuilder

Methods

showsPrec :: Int -> MultipartParam -> ShowS

show :: MultipartParam -> String

showList :: [MultipartParam] -> ShowS

data FileData

Represents a single file upload for the MultipartParam.

Constructors

FileData

Fields

• fdFileName :: ByteString

  the file's name

• fdContentType :: ByteString

  the file's content-type

• fdContents :: ByteString

  the file contents

Instances

Show FileData

Defined in Snap.Internal.Test.RequestBuilder

Methods

showsPrec :: Int -> FileData -> ShowS

show :: FileData -> String

showList :: [FileData] -> ShowS

data RequestType

The RequestType datatype enumerates the different kinds of HTTP requests you can generate using the testing interface. Most users will prefer to use the get, postUrlEncoded, postMultipart, put, and delete convenience functions.

Constructors

GetRequest

RequestWithRawBody Method ByteString

MultipartPostRequest MultipartParams

UrlEncodedPostRequest Params

DeleteRequest

Instances

Show RequestType

Defined in Snap.Internal.Test.RequestBuilder

Methods

showsPrec :: Int -> RequestType -> ShowS

show :: RequestType -> String

showList :: [RequestType] -> ShowS

Building Requests and testing handlers

buildRequest :: MonadIO m => RequestBuilder m () -> m Request

Runs a RequestBuilder, producing the desired Request.

N.B. please don't use the request you get here in a real Snap application; things will probably break. Don't say you weren't warned :-)

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified Data.Map as M
ghci> buildRequest $ get "/foo/bar" M.empty
GET /foo/bar HTTP/1.1
host: localhost

sn="localhost" c=127.0.0.1:60000 s=127.0.0.1:8080 ctx=/ clen=n/a

runHandler

Arguments

:: MonadIO m

=> RequestBuilder m ()

a request builder

-> Snap a

a web handler

-> m Response

Given a web handler in the Snap monad, and a RequestBuilder defining a test request, runs the handler, producing an HTTP Response.

This function will produce almost exactly the same output as running the handler in a real server, except that chunked transfer encoding is not applied, and the "Transfer-Encoding" header is not set (this makes it easier to test response output).

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified Data.Map as M
ghci> import Snap.Core
ghci> runHandler (get "foo/bar" M.empty) (writeBS "Hello, world!")
HTTP/1.1 200 OK
server: Snap/test
date: Thu, 17 Jul 2014 21:03:23 GMT

Hello, world!

runHandlerM

Arguments

:: (MonadIO m, MonadSnap n)

=> (forall a. Request -> n a -> m Response)

a function defining how the MonadSnap monad should be run

-> RequestBuilder m ()

a request builder

-> n b

a web handler

-> m Response

Given a web handler in some arbitrary MonadSnap monad, a function specifying how to evaluate it within the context of the test monad, and a RequestBuilder defining a test request, runs the handler, producing an HTTP Response.

evalHandler :: MonadIO m => RequestBuilder m () -> Snap a -> m a

Given a web handler in the Snap monad, and a RequestBuilder defining a test request, runs the handler and returns the monadic value it produces.

Throws an exception if the Snap handler early-terminates with finishWith or mzero.

Example:

ghci> :set -XOverloadedStrings
ghci> import Control.Monad
ghci> import qualified Data.Map as M
ghci> import Snap.Core
ghci> evalHandler (get "foo/bar" M.empty) (writeBS "Hello, world!" >> return 42)
42
ghci> evalHandler (get "foo/bar" M.empty) mzero
*** Exception: No handler for request: failure was pass

evalHandlerM

Arguments

:: (MonadIO m, MonadSnap n)

=> (forall a. Request -> n a -> m a)

a function defining how the MonadSnap monad should be run

-> RequestBuilder m ()

a request builder

-> n b

a web handler

-> m b

Given a web handler in some arbitrary MonadSnap monad, a function specifying how to evaluate it within the context of the test monad, and a RequestBuilder defining a test request, runs the handler, returning the monadic value it produces.

Throws an exception if the Snap handler early-terminates with finishWith or mzero.

Convenience functions for generating common types of HTTP requests

get

Arguments

:: MonadIO m

=> ByteString

request path

-> Params

request's form parameters

-> RequestBuilder m ()

Builds an HTTP "GET" request with the given query parameters.

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified Data.Map as M
ghci> buildRequest $ get "/foo/bar" (M.fromList [("param0", ["baz", "quux"])])
GET /foo/bar?param0=baz&param0=quux HTTP/1.1
host: localhost

sn="localhost" c=127.0.0.1:60000 s=127.0.0.1:8080 ctx=/ clen=n/a
params: param0: ["baz","quux"]

head :: [a] -> a

\(\mathcal{O}(1)\). Extract the first element of a list, which must be non-empty.

>>> head [1, 2, 3]
1
>>> head [1..]
1
>>> head []
*** Exception: Prelude.head: empty list

postUrlEncoded

Arguments

:: MonadIO m

=> ByteString

request path

-> Params

request's form parameters

-> RequestBuilder m ()

Builds an HTTP "POST" request with the given form parameters, using the "application/x-www-form-urlencoded" MIME type.

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified Data.Map as M
ghci> buildRequest $ postUrlEncoded "/foo/bar" (M.fromList [("param0", ["baz", "quux"])])
POST /foo/bar HTTP/1.1
content-type: application/x-www-form-urlencoded
content-length: 22
host: localhost

sn="localhost" c=127.0.0.1:60000 s=127.0.0.1:8080 ctx=/ clen=22
params: param0: ["baz","quux"]

postMultipart

Arguments

:: MonadIO m

=> ByteString

request path

-> MultipartParams

multipart form parameters

-> RequestBuilder m ()

Builds an HTTP "POST" request with the given form parameters, using the "form-data/multipart" MIME type.

Example:

ghci> :set -XOverloadedStrings
ghci> buildRequest $ postMultipart "/foo/bar" [("param0", FormData ["baz", "quux"])]
POST /foo/bar HTTP/1.1
content-type: multipart/form-data; boundary=snap-boundary-572334111ec0c05ad4812481e8585dfa
content-length: 406
host: localhost

sn="localhost" c=127.0.0.1:60000 s=127.0.0.1:8080 ctx=/ clen=406

put

Arguments

:: MonadIO m

=> ByteString

request path

-> ByteString

request body MIME content-type

-> ByteString

request body contents

-> RequestBuilder m ()

Builds an HTTP "PUT" request.

Example:

ghci> :set -XOverloadedStrings
ghci> buildRequest $ put "/foo/bar" "text/plain" "some text"
PUT /foo/bar HTTP/1.1
content-type: text/plain
content-length: 9
host: localhost

sn="localhost" c=127.0.0.1:60000 s=127.0.0.1:8080 ctx=/ clen=9

postRaw

Arguments

:: MonadIO m

=> ByteString

request path

-> ByteString

request body MIME content-type

-> ByteString

request body contents

-> RequestBuilder m ()

Builds a "raw" HTTP "POST" request, with the given MIME type and body contents.

Example:

ghci> :set -XOverloadedStrings
ghci> buildRequest $ postRaw "/foo/bar" "text/plain" "some text"
POST /foo/bar HTTP/1.1
content-type: text/plain
content-length: 9
host: localhost

sn="localhost" c=127.0.0.1:60000 s=127.0.0.1:8080 ctx=/ clen=9

delete

Arguments

:: MonadIO m

=> ByteString

request path

-> Params

request's form parameters

-> RequestBuilder m ()

Builds an HTTP "DELETE" request with the given query parameters.

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified Data.Map as M
ghci> buildRequest $ delete "/foo/bar" M.empty
DELETE /foo/bar HTTP/1.1
host: localhost

sn="localhost" c=127.0.0.1:60000 s=127.0.0.1:8080 ctx=/ clen=n/a

Precise control over building Requests

addHeader :: Monad m => CI ByteString -> ByteString -> RequestBuilder m ()

Adds the given header to the request being built.

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified Data.Map as M
ghci> :{
ghci| buildRequest $ do get "/foo/bar" M.empty
ghci|                   addHeader "Accept" "text/html"
ghci|                   addHeader "Accept" "text/plain"
ghci| :}
GET /foo/bar HTTP/1.1
accept: text/html,text/plain
host: localhost

sn="localhost" c=127.0.0.1:60000 s=127.0.0.1:8080 ctx=/ clen=n/a

setContentType :: Monad m => ByteString -> RequestBuilder m ()

Sets the request's content-type to the given MIME type.

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified Data.Map as M
ghci> buildRequest $ put "/foo/bar" "text/html" "some text" >> setContentType "text/plain"
PUT /foo/bar HTTP/1.1
content-type: text/plain
content-length: 9
host: localhost

sn="localhost" c=127.0.0.1:60000 s=127.0.0.1:8080 ctx=/ clen=9

setHeader :: Monad m => CI ByteString -> ByteString -> RequestBuilder m ()

Sets the given header in the request being built, overwriting any header with the same name already present.

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified Data.Map as M
ghci> :{
ghci| buildRequest $ do get "/foo/bar" M.empty
ghci|                   setHeader "Accept" "text/html"
ghci|                   setHeader "Accept" "text/plain"
ghci| :}
GET /foo/bar HTTP/1.1
accept: text/plain
host: localhost

sn="localhost" c=127.0.0.1:60000 s=127.0.0.1:8080 ctx=/ clen=n/a

addCookies :: Monad m => [Cookie] -> RequestBuilder m ()

Adds the given cookies to the request being built.

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified Data.Map as M
ghci> import Snap.Core
ghci> let cookie = Cookie "name" "value" Nothing Nothing Nothing False False
ghci> buildRequest $ get "/foo/bar" M.empty >> addCookies [cookie]
GET /foo/bar HTTP/1.1
cookie: name=value
host: localhost

sn="localhost" c=127.0.0.1:60000 s=127.0.0.1:8080 ctx=/ clen=n/a
cookies: Cookie {cookieName = "name", cookieValue = "value", ...}

setHttpVersion :: Monad m => (Int, Int) -> RequestBuilder m ()

Sets the test request's http version

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified Data.Map as M
ghci> buildRequest $ delete "/foo/bar" M.empty >> setHttpVersion (1,0)
DELETE /foo/bar HTTP/1.0
host: localhost

sn="localhost" c=127.0.0.1:60000 s=127.0.0.1:8080 ctx=/ clen=n/a

setQueryString :: Monad m => Params -> RequestBuilder m ()

Escapes the given parameter mapping and sets it as the request's query string.

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified Data.Map as M
ghci> buildRequest $ get "/foo/bar" M.empty >> setQueryString (M.fromList [("param0", ["baz"]), ("param1", ["qux"])])
GET /foo/bar?param0=baz&param1=qux HTTP/1.1
host: localhost

sn="localhost" c=127.0.0.1:60000 s=127.0.0.1:8080 ctx=/ clen=n/a
params: param0: ["baz"], param1: ["qux"]

setQueryStringRaw :: Monad m => ByteString -> RequestBuilder m ()

Sets the request's query string to be the raw bytestring provided, without any escaping or other interpretation. Most users should instead choose the setQueryString function, which takes a parameter mapping.

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified Data.Map as M
ghci> buildRequest $ get "/foo/bar" M.empty >> setQueryStringRaw "param0=baz&param1=qux"
GET /foo/bar?param0=baz&param1=qux HTTP/1.1
host: localhost

sn="localhost" c=127.0.0.1:60000 s=127.0.0.1:8080 ctx=/ clen=n/a
params: param0: ["baz"], param1: ["qux"]

setRequestPath :: Monad m => ByteString -> RequestBuilder m ()

Sets the request's path. The path provided must begin with a "/" and must not contain a query string; if you want to provide a query string in your test request, you must use setQueryString or setQueryStringRaw. Note that rqContextPath is never set by any RequestBuilder function.

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified Data.Map as M
ghci> buildRequest $ get "/foo/bar" M.empty >> setRequestPath "/bar/foo"
GET /bar/foo HTTP/1.1
host: localhost

sn="localhost" c=127.0.0.1:60000 s=127.0.0.1:8080 ctx=/ clen=n/a

setRequestType :: MonadIO m => RequestType -> RequestBuilder m ()

Sets the type of the Request being built.

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified Data.Map as M
ghci> buildRequest $ delete "/foo/bar" M.empty >> setRequestType GetRequest
GET /foo/bar HTTP/1.1
host: localhost

sn="localhost" c=127.0.0.1:60000 s=127.0.0.1:8080 ctx=/ clen=n/a

setSecure :: Monad m => Bool -> RequestBuilder m ()

Controls whether the test request being generated appears to be an https request or not.

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified Data.Map as M
ghci> buildRequest $ delete "/foo/bar" M.empty >> setSecure True
DELETE /foo/bar HTTP/1.1
host: localhost

sn="localhost" c=127.0.0.1:60000 s=127.0.0.1:8080 ctx=/ clen=n/a secure

HUnit Assertions

assertSuccess :: Response -> Assertion

Given a Response, assert that its HTTP status code is 200 (success).

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified Test.HUnit as T
ghci> let test = T.runTestTT . T.TestCase
ghci> test $ assertSuccess emptyResponse
Cases: 1  Tried: 1  Errors: 0  Failures: 0
Counts {cases = 1, tried = 1, errors = 0, failures = 0}
ghci> test $ assertSuccess (setResponseStatus 500 "Internal Server Error" emptyResponse)
### Failure:
Expected success (200) but got (500)
expected: 200
 but got: 500
Cases: 1  Tried: 1  Errors: 0  Failures: 1
Counts {cases = 1, tried = 1, errors = 0, failures = 1}

assert404 :: Response -> Assertion

Given a Response, assert that its HTTP status code is 404 (Not Found).

Example:

ghci> :set -XOverloadedStrings
ghci> assert404 $ setResponseStatus 404 "Not Found" emptyResponse
ghci> assert404 emptyResponse
*** Exception: HUnitFailure "Expected Not Found (404) but got (200)\nexpected: 404\n but got: 200"

assertRedirectTo

Arguments

:: ByteString

The Response should redirect to this URI

-> Response

-> Assertion

Given a Response, assert that its HTTP status code is between 300 and 399 (a redirect), and that the Location header of the Response points to the specified URI.

Example:

ghci> :set -XOverloadedStrings
ghci> let r' = setResponseStatus 301 "Moved Permanently" emptyResponse
ghci> let r  = setHeader "Location" "www.example.com" r'
ghci> assertRedirectTo "www.example.com" r
ghci> assertRedirectTo "www.example.com" emptyResponse
*** Exception: HUnitFailure "Expected redirect but got status code (200)"

assertRedirect :: Response -> Assertion

Given a Response, assert that its HTTP status code is between 300 and 399 (a redirect).

Example:

ghci> :set -XOverloadedStrings
ghci> assertRedirect $ setResponseStatus 301 "Moved Permanently" emptyResponse
ghci> assertRedirect emptyResponse
*** Exception: HUnitFailure "Expected redirect but got status code (200)"

assertBodyContains

Arguments

:: ByteString

Regexp that will match the body content

-> Response

-> Assertion

Given a Response, assert that its body matches the given regular expression.

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified System.IO.Streams as Streams
ghci> import qualified Data.ByteString.Builder as Builder
ghci> :{
ghci| let r = setResponseBody
ghci|         (out -> do
ghci|             Streams.write (Just $ Builder.byteString "Hello, world!") out
ghci|             return out)
ghci|         emptyResponse
ghci| :}
ghci> assertBodyContains "^Hello" r
ghci> assertBodyContains "Bye" r
*** Exception: HUnitFailure "Expected body to match regexp \"\"Bye\"\", but didn't"

Getting response bodies

getResponseBody :: Response -> IO ByteString

Given a Response, return its body as a ByteString.

Example:

ghci> getResponseBody emptyResponse
""

Dumping HTTP Messages

requestToString :: Request -> IO ByteString

Converts the given Request to a bytestring.

Since: 1.0.0.0

Example:

ghci> :set -XOverloadedStrings
ghci> import qualified Data.Map as M
ghci> r <- buildRequest $ get "/foo/bar" M.empty
ghci> requestToString r
"GET /foo/bar HTTP/1.1\r\nhost: localhost\r\n\r\n"

responseToString :: Response -> IO ByteString

Converts the given Response to a bytestring.

Example:

ghci> import Snap.Core
ghci> responseToString emptyResponse
"HTTP/1.1 200 OK\r\n\r\n"