refactor(oohelperd): better distinguish different helpers (#434)

Part of https://github.com/ooni/probe/issues/1733

internal/cmd/oohelperd/internal/webconnectivity/http_test.go

@@ -0,0 +1,57 @@
+package webconnectivity
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"strings"
+	"sync"
+	"testing"
+)
+
+func TestHTTPDoWithInvalidURL(t *testing.T) {
+	ctx := context.Background()
+	wg := new(sync.WaitGroup)
+	httpch := make(chan CtrlHTTPResponse, 1)
+	wg.Add(1)
+	go HTTPDo(ctx, &HTTPConfig{
+		Client:            http.DefaultClient,
+		Headers:           nil,
+		MaxAcceptableBody: 1 << 24,
+		Out:               httpch,
+		URL:               "http://[::1]aaaa",
+		Wg:                wg,
+	})
+	// wait for measurement steps to complete
+	wg.Wait()
+	resp := <-httpch
+	if resp.Failure == nil || !strings.HasSuffix(*resp.Failure, `invalid port "aaaa" after host`) {
+		t.Fatal("not the failure we expected")
+	}
+}
+
+func TestHTTPDoWithHTTPTransportFailure(t *testing.T) {
+	expected := errors.New("mocked error")
+	ctx := context.Background()
+	wg := new(sync.WaitGroup)
+	httpch := make(chan CtrlHTTPResponse, 1)
+	wg.Add(1)
+	go HTTPDo(ctx, &HTTPConfig{
+		Client: &http.Client{
+			Transport: FakeTransport{
+				Err: expected,
+			},
+		},
+		Headers:           nil,
+		MaxAcceptableBody: 1 << 24,
+		Out:               httpch,
+		URL:               "http://www.x.org",
+		Wg:                wg,
+	})
+	// wait for measurement steps to complete
+	wg.Wait()
+	resp := <-httpch
+	if resp.Failure == nil || !strings.HasSuffix(*resp.Failure, "mocked error") {
+		t.Fatal("not the error we expected")
+	}
+}