fix: capture jikan api error body in api error struct

integrations/jikan/transport/client_test.go

@@ -0,0 +1,55 @@
+package transport
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"io"
+	"net/http"
+	"strings"
+	"testing"
+)
+
+func TestHandleStatusRetryLeavesOutputUntouched(t *testing.T) {
+	out := struct {
+		Data []struct {
+			MalID int `json:"mal_id"`
+		} `json:"data"`
+	}{
+		Data: []struct {
+			MalID int `json:"mal_id"`
+		}{{MalID: 123}},
+	}
+	resp := &http.Response{
+		StatusCode: http.StatusNotFound,
+		Body:       io.NopCloser(strings.NewReader(`{"data":[{"mal_id":999}]}`)),
+		Header:     make(http.Header),
+	}
+
+	statusCode, retry, err := handleResponseRetry(context.Background(), resp, "https://example.test/anime/1", &out, 0, 1)
+	if statusCode != http.StatusNotFound {
+		t.Fatalf("statusCode = %d, want %d", statusCode, http.StatusNotFound)
+	}
+	if retry {
+		t.Fatal("retry = true, want false")
+	}
+	var apiErr *APIError
+	if !errors.As(err, &apiErr) {
+		t.Fatalf("err = %v, want APIError", err)
+	}
+	if len(out.Data) != 1 || out.Data[0].MalID != 123 {
+		t.Fatalf("out = %+v, want original value", out)
+	}
+
+	var body struct {
+		Data []struct {
+			MalID int `json:"mal_id"`
+		} `json:"data"`
+	}
+	if err := json.Unmarshal(apiErr.Body, &body); err != nil {
+		t.Fatalf("unmarshal APIError body: %v", err)
+	}
+	if len(body.Data) != 1 || body.Data[0].MalID != 999 {
+		t.Fatalf("APIError body = %+v, want decoded error body", body)
+	}
+}