Failed pattern match

API.purs

module Krank.API where

import Prelude

import Control.Monad.Error.Class (throwError)
import Data.Either (either)
import Effect.Aff (Aff)
import Effect.Class (liftEffect)
import Effect.Console as C
import Effect.Exception (error)
import Network.HTTP.Affjax (get)
import Network.HTTP.Affjax.Response (string)
import Simple.JSON (class ReadForeign, readJSON)

-- | Fetch JSON from an API endpoint on the backend.
fetchJSON ∷ ∀ a. ReadForeign a => Show a => String → Aff a
fetchJSON url = do
  { response } ← get string url
  either onError pure $ readJSON response
  where
    onError err = do
      let desc = "Unable to parse JSON response from " <> url <> ": " <> (show err)
      liftEffect $ C.error desc
      throwError $ error $ desc

console.log

Unable to parse JSON response from /krank/commit-api/8107: (NonEmptyList (NonEmpty (ErrorAtProperty "objects" (ErrorAtProperty "attributes" (ErrorAtProperty "params" (ErrorAtProperty "valuespace" (ForeignError "Unable to parse valuespace"))))) ((ErrorAtProperty "objects" (ErrorAtProperty "attributes" (ErrorAtProperty "read" (TypeMismatch "String" "Undefined")))) : (ErrorAtProperty "objects" (ErrorAtProperty "attributes" (ErrorAtProperty "read" (TypeMismatch "String" "Undefined")))) : Nil))) index.js:2178
[Show/hide message details.] TypeError: v is null[Learn More] Aff.purs:88
isLeft
Aff.purs:88
join
Aff.js:720
join/kills[kid]</<
Aff.js:778
<anonymous>
Aff.js:669
runEff
Aff.js:80
run
Aff.js:496
run/step</</<
Aff.js:333
drain
Aff.js:120
enqueue
Aff.js:141
run/step</<
Aff.js:330
__do/v1<
Compat.purs:25
./.psc-package/psc-0.12.0/affjax/v6.0.0/src/Network/HTTP/Affjax.js/</exports._ajax</</</xhr.onload
Affjax.js:60

isLeft

isLeft
src/krank/js/.psc-package/psc-0.12.0/aff/v5.0.0/src/Effect/Aff.purs:88

  85 |     if (v instanceof Data_Either.Right) {
  86 |         return false;
  87 |     };
> 88 |     throw new Error("Failed pattern match at Effect.Aff line 385, column 12 - line 387, column 20: " + [ v.constructor.name ]);
  89 | };
  90 | return {
  91 |     isLeft: isLeft,