fix: auto generate TraverseTuple for ReaderIOEither

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

samples/http/http_test.go

@@ -13,6 +13,7 @@ import (
 	E "github.com/IBM/fp-go/either"
 	F "github.com/IBM/fp-go/function"
 	IO "github.com/IBM/fp-go/io"
+	T "github.com/IBM/fp-go/tuple"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -23,13 +24,20 @@ type PostItem struct {
 	Body   string `json:"body"`
 }
 
+type CatFact struct {
+	Fact string `json:"fact"`
+}
+
 func idxToUrl(idx int) string {
 	return fmt.Sprintf("https://jsonplaceholder.typicode.com/posts/%d", idx+1)
 }
 
+// TestMultipleHttpRequests shows how to execute multiple HTTP requests in parallel assuming
+// that the response structure of all requests is identical, which is why we can use [R.TraverseArray]
 func TestMultipleHttpRequests(t *testing.T) {
 	// prepare the http client
 	client := H.MakeClient(HTTP.DefaultClient)
+	// readSinglePost sends a GET request and parses the response as [PostItem]
 	readSinglePost := H.ReadJson[PostItem](client)
 
 	// total number of http requests
@@ -50,3 +58,28 @@ func TestMultipleHttpRequests(t *testing.T) {
 
 	assert.Equal(t, E.Of[error](count), result())
 }
+
+// TestHeterogeneousHttpRequests shows how to execute multiple HTTP requests in parallel when
+// the response structure of these requests is different. We use [R.TraverseTuple2] to account for the different types
+func TestHeterogeneousHttpRequests(t *testing.T) {
+	// prepare the http client
+	client := H.MakeClient(HTTP.DefaultClient)
+	// readSinglePost sends a GET request and parses the response as [PostItem]
+	readSinglePost := H.ReadJson[PostItem](client)
+	// readSingleCatFact sends a GET request and parses the response as [CatFact]
+	readSingleCatFact := H.ReadJson[CatFact](client)
+
+	data := F.Pipe3(
+		T.MakeTuple2("https://jsonplaceholder.typicode.com/posts/1", "https://catfact.ninja/fact"),
+		T.Map2(H.MakeGetRequest, H.MakeGetRequest),
+		R.TraverseTuple2(
+			readSinglePost,
+			readSingleCatFact,
+		),
+		R.ChainFirstIOK(IO.Logf[T.Tuple2[PostItem, CatFact]]("Log Result: %v")),
+	)
+
+	result := data(context.Background())
+
+	fmt.Println(result())
+}