Make response headers a map

CHANGELOG.md

@@ -5,6 +5,7 @@ Notable changes to this project are documented in this file. The format is based
 ## [Unreleased]
 
 Breaking changes:
+- Switch response headers to `Map CaseInsensitiveString String`
 
 New features:
 Bugfixes:

spago.dhall

@@ -3,11 +3,14 @@
   [ "aff"
   , "aff-promise"
   , "arraybuffer-types"
+  , "bifunctors"
   , "effect"
   , "fetch-core"
   , "foreign"
   , "http-methods"
+  , "maybe"
   , "newtype"
+  , "ordered-collections"
   , "prelude"
   , "record"
   , "typelevel-prelude"

src/Fetch.purs

@@ -10,6 +10,7 @@ module Fetch
   , module Fetch.Internal.Request
   , module Fetch.Internal.RequestBody
   , module Fetch.Internal.Response
+  , module Fetch.Internal.Headers
   ) where
 
 import Prelude
@@ -27,6 +28,7 @@ import Fetch.Core.RequestCredentials (RequestCredentials(Omit, Include))
 import Fetch.Core.RequestMode (RequestMode(Cors, NoCors, Navigate))
 import Fetch.Internal.Request (class ToCoreRequestOptions, class ToCoreRequestOptionsConverter, class ToCoreRequestOptionsHelper, HighlevelRequestOptions, convertHelper, convertImpl, new)
 import Fetch.Internal.Request as Request
+import Fetch.Internal.Headers (lookup, toHeaders, contains)
 import Fetch.Internal.RequestBody (class ToRequestBody, toRequestBody)
 import Fetch.Internal.Response (Response, ResponseR, arrayBuffer, blob, body, json, promiseToPromise, text)
 import Fetch.Internal.Response as Response

src/Fetch/Internal/Headers.purs

@@ -0,0 +1,22 @@
+module Fetch.Internal.Headers
+  ( contains
+  , lookup
+  , toHeaders
+  ) where
+
+import Prelude
+
+import Data.Bifunctor (lmap)
+import Data.Map as Map
+import Data.Maybe (Maybe)
+import Data.String.CaseInsensitive (CaseInsensitiveString(..))
+import Fetch.Core.Headers as CoreHeaders
+
+toHeaders :: CoreHeaders.Headers -> Map.Map CaseInsensitiveString String
+toHeaders = CoreHeaders.toArray >>> map (lmap CaseInsensitiveString) >>> Map.fromFoldable
+
+lookup :: String -> Map.Map CaseInsensitiveString String -> Maybe String
+lookup key headers = Map.lookup (CaseInsensitiveString key) headers
+
+contains ∷ String → Map.Map CaseInsensitiveString String → Boolean
+contains key headers = Map.member (CaseInsensitiveString key) headers

src/Fetch/Internal/Response.purs

@@ -15,10 +15,14 @@ import Prelude
 import Control.Promise as Control
 import Control.Promise as Promise
 import Data.ArrayBuffer.Types (ArrayBuffer, Uint8Array)
+import Data.Bifunctor (lmap)
+import Data.Map as Map
+import Data.String.CaseInsensitive (CaseInsensitiveString(..))
 import Effect (Effect)
 import Effect.Aff (Aff)
-import Fetch.Core.Headers (Headers)
+import Fetch.Core.Headers as CoreHeaders
 import Fetch.Core.Response as CoreResponse
+import Fetch.Internal.Headers (toHeaders)
 import Foreign (Foreign)
 import Unsafe.Coerce (unsafeCoerce)
 import Web.File.Blob (Blob)
@@ -26,7 +30,7 @@ import Web.Promise as Web
 import Web.Streams.ReadableStream (ReadableStream)
 
 type ResponseR =
-  ( headers :: Headers
+  ( headers :: Map.Map CaseInsensitiveString String
   , ok :: Boolean
   , redirected :: Boolean
   , status :: Int
@@ -63,7 +67,7 @@ promiseToPromise = unsafeCoerce
 
 convert :: CoreResponse.Response -> Response
 convert response =
-  { headers: CoreResponse.headers response
+  { headers: CoreResponse.headers response # toHeaders
   , ok: CoreResponse.ok response
   , redirected: CoreResponse.redirected response
   , status: CoreResponse.status response

test/Test/FetchSpec.purs

@@ -3,7 +3,9 @@ module Test.FetchSpec where
 import Prelude
 
 import Data.ArrayBuffer.Types (Uint8Array)
+import Data.Maybe (Maybe(..))
 import Fetch (Method(..), Referrer(..), RequestMode(..), fetch, fetchBody)
+import Fetch as Fetch
 import Foreign (unsafeFromForeign)
 import Test.Spec (Spec, describe, it)
 import Test.Spec.Assertions (shouldEqual)
@@ -49,3 +51,15 @@ spec =
         { json: j } <- json <#> unsafeFromForeign
         j `shouldEqual` { hello: "world" }
         status `shouldEqual` 200
+
+      it "should retrieve correct headers" do
+
+        { status, headers } <- fetch "https://httpbin.org/post"
+          { method: POST
+          , body: """{"hello":"world"}"""
+          , headers: { "Content-Type": "application/json" }
+          }
+        Fetch.lookup "Access-Control-Allow-Origin" headers `shouldEqual` Just "*"
+        Fetch.lookup "Content-Type" headers `shouldEqual` Just "application/json"
+        Fetch.contains "Content-Length" headers `shouldEqual` true
+        status `shouldEqual` 200