doc: add sample for http

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

samples/http/http_test.go

@@ -0,0 +1,52 @@
+package http
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	HTTP "net/http"
+
+	A "github.com/IBM/fp-go/array"
+	R "github.com/IBM/fp-go/context/readerioeither"
+	H "github.com/IBM/fp-go/context/readerioeither/http"
+	E "github.com/IBM/fp-go/either"
+	F "github.com/IBM/fp-go/function"
+	IO "github.com/IBM/fp-go/io"
+	"github.com/stretchr/testify/assert"
+)
+
+type PostItem struct {
+	UserId uint   `json:"userId"`
+	Id     uint   `json:"id"`
+	Title  string `json:"title"`
+	Body   string `json:"body"`
+}
+
+func idxToUrl(idx int) string {
+	return fmt.Sprintf("https://jsonplaceholder.typicode.com/posts/%d", idx+1)
+}
+
+func TestMultipleHttpRequests(t *testing.T) {
+	// prepare the http client
+	client := H.MakeClient(HTTP.DefaultClient)
+	readSinglePost := H.ReadJson[PostItem](client)
+
+	// total number of http requests
+	count := 10
+
+	data := F.Pipe3(
+		A.MakeBy(count, idxToUrl),
+		R.TraverseArray(F.Flow3(
+			H.MakeGetRequest,
+			readSinglePost,
+			R.ChainFirstIOK(IO.Logf[PostItem]("Log Single: %v")),
+		)),
+		R.ChainFirstIOK(IO.Logf[[]PostItem]("Log Result: %v")),
+		R.Map(A.Size[PostItem]),
+	)
+
+	result := data(context.Background())
+
+	assert.Equal(t, E.Of[error](count), result())
+}