42bf4475e0
* Update shell and packages * Fix code for 0.15 * Fix tests * Format * Add check-pulp command * Generate bowerfile * Add check-pulp to CI * Add nixfmt to formatting * Fixup test helpers * Take 2 * PR comments (#1) * Nix cleanup from PR * Use arrows functions * Remove unnecessary step Co-authored-by: Connor Prussin <connor@prussin.net>
70 lines
2.6 KiB
Haskell
70 lines
2.6 KiB
Haskell
module Examples.Middleware.Main where
|
|
|
|
import Prelude
|
|
|
|
import Effect.Class (liftEffect)
|
|
import Effect.Console (log)
|
|
import HTTPure (Request, ResponseM, ServerM, fullPath, header, ok, ok', serve)
|
|
|
|
-- | A middleware that logs at the beginning and end of each request
|
|
loggingMiddleware ::
|
|
(Request -> ResponseM) ->
|
|
Request ->
|
|
ResponseM
|
|
loggingMiddleware router request = do
|
|
liftEffect $ log $ "Request starting for " <> path
|
|
response <- router request
|
|
liftEffect $ log $ "Request ending for " <> path
|
|
pure response
|
|
where
|
|
path = fullPath request
|
|
|
|
-- | A middleware that adds the X-Middleware header to the response, if it
|
|
-- | wasn't already in the response
|
|
headerMiddleware ::
|
|
(Request -> ResponseM) ->
|
|
Request ->
|
|
ResponseM
|
|
headerMiddleware router request = do
|
|
response@{ headers } <- router request
|
|
pure $ response { headers = header' <> headers }
|
|
where
|
|
header' = header "X-Middleware" "middleware"
|
|
|
|
-- | A middleware that sends the body "Middleware!" instead of running the
|
|
-- | router when requesting /middleware
|
|
pathMiddleware ::
|
|
(Request -> ResponseM) ->
|
|
Request ->
|
|
ResponseM
|
|
pathMiddleware _ { path: [ "middleware" ] } = ok "Middleware!"
|
|
pathMiddleware router request = router request
|
|
|
|
-- | Say 'hello' when run, and add a default value to the X-Middleware header
|
|
sayHello :: Request -> ResponseM
|
|
sayHello _ = ok' (header "X-Middleware" "router") "hello"
|
|
|
|
-- | The stack of middlewares to use for the server
|
|
middlewareStack :: (Request -> ResponseM) -> Request -> ResponseM
|
|
middlewareStack = loggingMiddleware <<< headerMiddleware <<< pathMiddleware
|
|
|
|
-- | Boot up the server
|
|
main :: ServerM
|
|
main =
|
|
serve 8080 (middlewareStack sayHello) do
|
|
log " ┌───────────────────────────────────────┐"
|
|
log " │ Server now up on port 8080 │"
|
|
log " │ │"
|
|
log " │ To test, run: │"
|
|
log " │ > curl -v localhost:8080 │"
|
|
log " │ # => ... │"
|
|
log " │ # => ...< X-Middleware: router │"
|
|
log " │ # => ... │"
|
|
log " │ # => hello │"
|
|
log " │ > curl -v localhost:8080/middleware │"
|
|
log " │ # => ... │"
|
|
log " │ # => ...< X-Middleware: middleware │"
|
|
log " │ # => ... │"
|
|
log " │ # => Middleware! │"
|
|
log " └───────────────────────────────────────┘"
|