feat: add twitch graphql streamer resolution

internal/twitch/service_test.go

@@ -0,0 +1,65 @@
+package twitch
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"testing"
+
+	"parasocial/internal/gql"
+)
+
+type fakeGQL struct {
+	requests []gql.Request
+	data     map[string]string
+}
+
+func (f *fakeGQL) Do(_ context.Context, request gql.Request, out any) error {
+	f.requests = append(f.requests, request)
+	return json.Unmarshal([]byte(f.data[request.OperationName]), out)
+}
+
+func TestCurrentUser(t *testing.T) {
+	t.Parallel()
+
+	client := &fakeGQL{data: map[string]string{
+		"CurrentUser": `{"currentUser":{"id":"7","login":"viewer"}}`,
+	}}
+	service := &Service{GQL: client}
+	viewer, err := service.CurrentUser(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if viewer.ID != "7" || viewer.Login != "viewer" {
+		t.Fatalf("viewer = %#v", viewer)
+	}
+}
+
+func TestResolveStreamer(t *testing.T) {
+	t.Parallel()
+
+	client := &fakeGQL{data: map[string]string{
+		"GetIDFromLogin": `{"user":{"id":"123","login":"streamer"}}`,
+	}}
+	service := &Service{GQL: client}
+	channel, err := service.ResolveStreamer(context.Background(), "streamer")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if channel.ID != "123" || channel.Login != "streamer" {
+		t.Fatalf("channel = %#v", channel)
+	}
+}
+
+func TestResolveStreamerNotFound(t *testing.T) {
+	t.Parallel()
+
+	client := &fakeGQL{data: map[string]string{
+		"GetIDFromLogin": `{"user":null}`,
+	}}
+	service := &Service{GQL: client}
+	_, err := service.ResolveStreamer(context.Background(), "missing")
+	if !errors.Is(err, ErrStreamerNotFound) {
+		t.Fatalf("error = %v", err)
+	}
+}