fix: http interface of IOEither

Signed-off-by: Dr. Carsten Leue <carsten.leue@de.ibm.com>

ioeither/generic/ioeither.go

@@ -275,6 +275,27 @@ func ChainFirstIOK[GA ~func() ET.Either[E, A], GIOB ~func() B, E, A, B any](f fu
 	)
 }
 
+// MonadChainFirstEitherK runs the monad returned by the function but returns the result of the original monad
+func MonadChainFirstEitherK[GA ~func() ET.Either[E, A], E, A, B any](first GA, f func(A) ET.Either[E, B]) GA {
+	return FE.MonadChainFirstEitherK(
+		MonadChain[GA, GA, E, A, A],
+		MonadMap[func() ET.Either[E, B], GA, E, B, A],
+		FromEither[func() ET.Either[E, B], E, B],
+		first,
+		f,
+	)
+}
+
+// ChainFirstEitherK runs the monad returned by the function but returns the result of the original monad
+func ChainFirstEitherK[GA ~func() ET.Either[E, A], E, A, B any](f func(A) ET.Either[E, B]) func(GA) GA {
+	return FE.ChainFirstEitherK(
+		MonadChain[GA, GA, E, A, A],
+		MonadMap[func() ET.Either[E, B], GA, E, B, A],
+		FromEither[func() ET.Either[E, B], E, B],
+		f,
+	)
+}
+
 // Swap changes the order of type parameters
 func Swap[GEA ~func() ET.Either[E, A], GAE ~func() ET.Either[A, E], E, A any](val GEA) GAE {
 	return MonadFold(val, Right[GAE], Left[GAE])

ioeither/http/request.go

@@ -20,54 +20,94 @@ import (
 	"net/http"
 
 	B "github.com/IBM/fp-go/bytes"
-	ER "github.com/IBM/fp-go/errors"
 	F "github.com/IBM/fp-go/function"
+	H "github.com/IBM/fp-go/http"
 	IOE "github.com/IBM/fp-go/ioeither"
 	IOEF "github.com/IBM/fp-go/ioeither/file"
 	J "github.com/IBM/fp-go/json"
+	T "github.com/IBM/fp-go/tuple"
 )
 
-type Client interface {
-	Do(req *http.Request) IOE.IOEither[error, *http.Response]
-}
+type (
+	// Requester is a reader that constructs a request
+	Requester = IOE.IOEither[error, *http.Request]
 
-type client struct {
-	delegate *http.Client
-}
+	Client interface {
+		Do(Requester) IOE.IOEither[error, *http.Response]
+	}
 
-func (client client) Do(req *http.Request) IOE.IOEither[error, *http.Response] {
-	return IOE.TryCatch(func() (*http.Response, error) {
-		return client.delegate.Do(req)
-	}, ER.IdentityError)
+	client struct {
+		delegate *http.Client
+		doIOE    func(*http.Request) IOE.IOEither[error, *http.Response]
+	}
+)
+
+var (
+	// MakeRequest is an eitherized version of [http.NewRequest]
+	MakeRequest = IOE.Eitherize3(http.NewRequest)
+	makeRequest = F.Bind13of3(MakeRequest)
+
+	// specialize
+	MakeGetRequest = makeRequest("GET", nil)
+)
+
+func (client client) Do(req Requester) IOE.IOEither[error, *http.Response] {
+	return F.Pipe1(
+		req,
+		IOE.Chain(client.doIOE),
+	)
 }
 
 func MakeClient(httpClient *http.Client) Client {
-	return client{delegate: httpClient}
+	return client{delegate: httpClient, doIOE: IOE.Eitherize1(httpClient.Do)}
 }
 
-func ReadAll(client Client) func(*http.Request) IOE.IOEither[error, []byte] {
-	return func(req *http.Request) IOE.IOEither[error, []byte] {
-		return IOEF.ReadAll(F.Pipe2(
-			req,
-			client.Do,
-			IOE.Map[error](func(resp *http.Response) io.ReadCloser {
-				return resp.Body
-			}),
-		),
-		)
-	}
+// ReadFullResponse sends a request,  reads the response as a byte array and represents the result as a tuple
+func ReadFullResponse(client Client) func(Requester) IOE.IOEither[error, H.FullResponse] {
+	return F.Flow3(
+		client.Do,
+		IOE.ChainEitherK(H.ValidateResponse),
+		IOE.Chain(func(resp *http.Response) IOE.IOEither[error, H.FullResponse] {
+			return F.Pipe1(
+				F.Pipe3(
+					resp,
+					H.GetBody,
+					IOE.Of[error, io.ReadCloser],
+					IOEF.ReadAll[io.ReadCloser],
+				),
+				IOE.Map[error](F.Bind1st(T.MakeTuple2[*http.Response, []byte], resp)),
+			)
+		}),
+	)
 }
 
-func ReadText(client Client) func(*http.Request) IOE.IOEither[error, string] {
+// ReadAll sends a request and reads the response as bytes
+func ReadAll(client Client) func(Requester) IOE.IOEither[error, []byte] {
+	return F.Flow2(
+		ReadFullResponse(client),
+		IOE.Map[error](H.Body),
+	)
+}
+
+// ReadText sends a request, reads the response and represents the response as a text string
+func ReadText(client Client) func(Requester) IOE.IOEither[error, string] {
 	return F.Flow2(
 		ReadAll(client),
 		IOE.Map[error](B.ToString),
 	)
 }
 
-func ReadJson[A any](client Client) func(*http.Request) IOE.IOEither[error, A] {
-	return F.Flow2(
-		ReadAll(client),
-		IOE.ChainEitherK(J.Unmarshal[A]),
+// ReadJson sends a request, reads the response and parses the response as JSON
+func ReadJson[A any](client Client) func(Requester) IOE.IOEither[error, A] {
+	return F.Flow3(
+		ReadFullResponse(client),
+		IOE.ChainFirstEitherK(F.Flow2(
+			H.Response,
+			H.ValidateJsonResponse,
+		)),
+		IOE.ChainEitherK(F.Flow2(
+			H.Body,
+			J.Unmarshal[A],
+		)),
 	)
 }

ioeither/http/retry_test.go

@@ -23,7 +23,6 @@ import (
 
 	AR "github.com/IBM/fp-go/array"
 	E "github.com/IBM/fp-go/either"
-	HE "github.com/IBM/fp-go/either/http"
 	"github.com/IBM/fp-go/errors"
 	F "github.com/IBM/fp-go/function"
 	IOE "github.com/IBM/fp-go/ioeither"
@@ -53,10 +52,9 @@ func TestRetryHttp(t *testing.T) {
 	client := MakeClient(&http.Client{})
 
 	action := func(status R.RetryStatus) IOE.IOEither[error, *PostItem] {
-		return F.Pipe2(
-			HE.GetRequest(urls[status.IterNumber]),
-			IOE.FromEither[error, *http.Request],
-			IOE.Chain(ReadJson[*PostItem](client)),
+		return F.Pipe1(
+			MakeGetRequest(urls[status.IterNumber]),
+			ReadJson[*PostItem](client),
 		)
 	}
 

ioeither/ioeither.go

@@ -211,6 +211,14 @@ func ChainFirst[E, A, B any](f func(A) IOEither[E, B]) func(IOEither[E, A]) IOEi
 	return G.ChainFirst[IOEither[E, A]](f)
 }
 
+func MonadChainFirstEitherK[A, E, B any](ma IOEither[E, A], f func(A) ET.Either[E, B]) IOEither[E, A] {
+	return G.MonadChainFirstEitherK[IOEither[E, A]](ma, f)
+}
+
+func ChainFirstEitherK[A, E, B any](f func(A) ET.Either[E, B]) func(ma IOEither[E, A]) IOEither[E, A] {
+	return G.ChainFirstEitherK[IOEither[E, A]](f)
+}
+
 // MonadChainFirstIOK runs [IO] the monad returned by the function but returns the result of the original monad
 func MonadChainFirstIOK[E, A, B any](ma IOEither[E, A], f func(A) I.IO[B]) IOEither[E, A] {
 	return G.MonadChainFirstIOK(ma, f)