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refactor(httpx): hide the real APIClient (#648)

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As mentioned in https://github.com/ooni/probe/issues/1951, one of
the main issues I did see with httpx.APIClient is that in some cases
it's used in a very fragile way by probeservices.Client.

This happens in psiphon.go and tor.go, where we create a copy of
the APIClient and then modify it's Authorization field.

If we ever refactor probeservices.Client to take a pointer to
httpx.Client, we are now mutating the httpx.Client.

Of course, we don't want that to happen.

This diff attempts to address such a problem as follows:

1. we create a new APIClientTemplate type that holds the same
fields of an APIClient and allows to build an APIClient

2. we modify every user of APIClient to use APIClientTemplate

3. when we need an APIClient, we build it from the corresponding
template and, when we need to use a specific Authorization, we
use a build factory that sets APIClient.Authorization

4. we hide APIClient by renaming it apiClient and by defining
an interface called APIClient that allows to use it

So, now the codebase always uses the opaque APIClient interface to
issue API calls and always uses the APIClientTemplate to build an
opaque APIClient.

Boom! We have separated construction from usage and we are not
mutating in weird ways the APIClient anymore.
This commit is contained in:
Simone Basso 2022-01-05 14:15:42 +01:00 committed by GitHub
parent 7b7df2c6af
commit eed51978ca
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
22 changed files with 159 additions and 64 deletions
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2
internal/cmd/apitool/main.go
View File

@ -28,7 +28,7 @@ func newclient() probeservices.Client {
txp := netxlite.NewHTTPTransportStdlib(log.Log)
ua := fmt.Sprintf("apitool/%s ooniprobe-engine/%s", version.Version, version.Version)
return probeservices.Client{
APIClient: httpx.APIClient{
APIClientTemplate: httpx.APIClientTemplate{
BaseURL: "https://ams-pg.ooni.org/",
HTTPClient: &http.Client{Transport: txp},
Logger: log.Log,

4
internal/engine/experiment/webconnectivity/control.go
View File

@ -53,7 +53,7 @@ type ControlResponse struct {
func Control(
ctx context.Context, sess model.ExperimentSession,
thAddr string, creq ControlRequest) (out ControlResponse, err error) {
clnt := &httpx.APIClient{
clnt := &httpx.APIClientTemplate{
BaseURL: thAddr,
HTTPClient: sess.DefaultHTTPClient(),
Logger: sess.Logger(),
@ -62,7 +62,7 @@ func Control(
sess.Logger().Infof("control for %s...", creq.HTTPRequest)
// make sure error is wrapped
err = legacyerrorsx.SafeErrWrapperBuilder{
Error: clnt.PostJSON(ctx, "/", creq, &out),
Error: clnt.Build().PostJSON(ctx, "/", creq, &out),
Operation: netxlite.TopLevelOperation,
}.MaybeBuild()
sess.Logger().Infof("control for %s... %+v", creq.HTTPRequest, err)

4
internal/engine/experiment/websteps/control.go
View File

@ -13,14 +13,14 @@ import (
func Control(
ctx context.Context, sess model.ExperimentSession,
thAddr string, resourcePath string, creq CtrlRequest) (out CtrlResponse, err error) {
clnt := &httpx.APIClient{
clnt := &httpx.APIClientTemplate{
BaseURL: thAddr,
HTTPClient: sess.DefaultHTTPClient(),
Logger: sess.Logger(),
}
// make sure error is wrapped
err = errorsxlegacy.SafeErrWrapperBuilder{
Error: clnt.PostJSON(ctx, resourcePath, creq, &out),
Error: clnt.Build().PostJSON(ctx, resourcePath, creq, &out),
Operation: netxlite.TopLevelOperation,
}.MaybeBuild()
return

4
internal/engine/geolocate/avast.go
View File

@ -19,12 +19,12 @@ func avastIPLookup(
userAgent string,
) (string, error) {
var v avastResponse
err := (&httpx.APIClient{
err := (&httpx.APIClientTemplate{
BaseURL: "https://ip-info.ff.avast.com",
HTTPClient: httpClient,
Logger: logger,
UserAgent: userAgent,
}).GetJSON(ctx, "/v1/info", &v)
}).Build().GetJSON(ctx, "/v1/info", &v)
if err != nil {
return DefaultProbeIP, err
}

4
internal/engine/geolocate/ipconfig.go
View File

@ -16,12 +16,12 @@ func ipConfigIPLookup(
logger model.Logger,
userAgent string,
) (string, error) {
data, err := (&httpx.APIClient{
data, err := (&httpx.APIClientTemplate{
BaseURL: "https://ipconfig.io",
HTTPClient: httpClient,
Logger: logger,
UserAgent: httpheader.CLIUserAgent(),
}).FetchResource(ctx, "/")
}).Build().FetchResource(ctx, "/")
if err != nil {
return DefaultProbeIP, err
}

4
internal/engine/geolocate/ipinfo.go
View File

@ -20,13 +20,13 @@ func ipInfoIPLookup(
userAgent string,
) (string, error) {
var v ipInfoResponse
err := (&httpx.APIClient{
err := (&httpx.APIClientTemplate{
Accept: "application/json",
BaseURL: "https://ipinfo.io",
HTTPClient: httpClient,
Logger: logger,
UserAgent: httpheader.CLIUserAgent(), // we must be a CLI client
}).GetJSON(ctx, "/", &v)
}).Build().GetJSON(ctx, "/", &v)
if err != nil {
return DefaultProbeIP, err
}

4
internal/engine/geolocate/ubuntu.go
View File

@ -20,12 +20,12 @@ func ubuntuIPLookup(
logger model.Logger,
userAgent string,
) (string, error) {
data, err := (&httpx.APIClient{
data, err := (&httpx.APIClientTemplate{
BaseURL: "https://geoip.ubuntu.com/",
HTTPClient: httpClient,
Logger: logger,
UserAgent: userAgent,
}).FetchResource(ctx, "/lookup")
}).Build().FetchResource(ctx, "/lookup")
if err != nil {
return DefaultProbeIP, err
}

94
internal/engine/httpx/httpx.go
View File

@ -15,13 +15,74 @@ import (
"github.com/ooni/probe-cli/v3/internal/netxlite"
)
// APIClientTemplate is a template for constructing an APIClient.
type APIClientTemplate struct {
// Accept contains the OPTIONAL accept header.
Accept string
// Authorization contains the OPTIONAL authorization header.
Authorization string
// BaseURL is the MANDATORY base URL of the API.
BaseURL string
// HTTPClient is the MANDATORY underlying http client to use.
HTTPClient model.HTTPClient
// Host allows to OPTIONALLY set a specific host header. This is useful
// to implement, e.g., cloudfronting.
Host string
// Logger is MANDATORY the logger to use.
Logger model.DebugLogger
// UserAgent is the OPTIONAL user agent to use.
UserAgent string
}
// Build creates an APIClient from the APIClientTemplate.
func (tmpl *APIClientTemplate) Build() APIClient {
return tmpl.BuildWithAuthorization("")
}
// BuildWithAuthorization creates an APIClient from the
// APIClientTemplate and ensures it uses the given authorization
// value for APIClient.Authorization in subsequent API calls.
func (tmpl *APIClientTemplate) BuildWithAuthorization(authorization string) APIClient {
ac := apiClient(*tmpl)
ac.Authorization = authorization
return &ac
}
// DefaultMaxBodySize is the default value for the maximum
// body size you can fetch using an APIClient.
const DefaultMaxBodySize = 1 << 22
// APIClient is an extended HTTP client. To construct this APIClient, make
// APIClient is a client configured to call a given API identified
// by a given baseURL and using a given model.HTTPClient.
type APIClient interface {
// GetJSON reads the JSON resource at resourcePath and unmarshals the
// results into output. The request is bounded by the lifetime of the
// context passed as argument. Returns the error that occurred.
GetJSON(ctx context.Context, resourcePath string, output interface{}) error
// GetJSONWithQuery is like GetJSON but also has a query.
GetJSONWithQuery(ctx context.Context, resourcePath string,
query url.Values, output interface{}) error
// PostJSON creates a JSON subresource of the resource at resourcePath
// using the JSON document at input and returning the result into the
// JSON document at output. The request is bounded by the context's
// lifetime. Returns the error that occurred.
PostJSON(ctx context.Context, resourcePath string, input, output interface{}) error
// FetchResource fetches the specified resource and returns it.
FetchResource(ctx context.Context, URLPath string) ([]byte, error)
}
// apiClient is an extended HTTP client. To construct this struct, make
// sure you initialize all fields marked as MANDATORY.
type APIClient struct {
type apiClient struct {
// Accept contains the OPTIONAL accept header.
Accept string
@ -46,7 +107,7 @@ type APIClient struct {
}
// newRequestWithJSONBody creates a new request with a JSON body
func (c *APIClient) newRequestWithJSONBody(
func (c *apiClient) newRequestWithJSONBody(
ctx context.Context, method, resourcePath string,
query url.Values, body interface{}) (*http.Request, error) {
data, err := json.Marshal(body)
@ -66,7 +127,7 @@ func (c *APIClient) newRequestWithJSONBody(
}
// newRequest creates a new request.
func (c *APIClient) newRequest(ctx context.Context, method, resourcePath string,
func (c *apiClient) newRequest(ctx context.Context, method, resourcePath string,
query url.Values, body io.Reader) (*http.Request, error) {
URL, err := url.Parse(c.BaseURL)
if err != nil {
@ -95,7 +156,7 @@ func (c *APIClient) newRequest(ctx context.Context, method, resourcePath string,
var ErrRequestFailed = errors.New("httpx: request failed")
// do performs the provided request and returns the response body or an error.
func (c *APIClient) do(request *http.Request) ([]byte, error) {
func (c *apiClient) do(request *http.Request) ([]byte, error) {
response, err := c.HTTPClient.Do(request)
if err != nil {
return nil, err
@ -114,7 +175,7 @@ func (c *APIClient) do(request *http.Request) ([]byte, error) {
// doJSON performs the provided request and unmarshals the JSON response body
// into the provided output variable.
func (c *APIClient) doJSON(request *http.Request, output interface{}) error {
func (c *apiClient) doJSON(request *http.Request, output interface{}) error {
data, err := c.do(request)
if err != nil {
return err
@ -123,15 +184,13 @@ func (c *APIClient) doJSON(request *http.Request, output interface{}) error {
return json.Unmarshal(data, output)
}
// GetJSON reads the JSON resource at resourcePath and unmarshals the
// results into output. The request is bounded by the lifetime of the
// context passed as argument. Returns the error that occurred.
func (c *APIClient) GetJSON(ctx context.Context, resourcePath string, output interface{}) error {
// GetJSON implements APIClient.GetJSON.
func (c *apiClient) GetJSON(ctx context.Context, resourcePath string, output interface{}) error {
return c.GetJSONWithQuery(ctx, resourcePath, nil, output)
}
// GetJSONWithQuery is like GetJSON but also has a query.
func (c *APIClient) GetJSONWithQuery(
// GetJSONWithQuery implements APIClient.GetJSONWithQuery.
func (c *apiClient) GetJSONWithQuery(
ctx context.Context, resourcePath string,
query url.Values, output interface{}) error {
request, err := c.newRequest(ctx, "GET", resourcePath, query, nil)
@ -141,11 +200,8 @@ func (c *APIClient) GetJSONWithQuery(
return c.doJSON(request, output)
}
// PostJSON creates a JSON subresource of the resource at resourcePath
// using the JSON document at input and returning the result into the
// JSON document at output. The request is bounded by the context's
// lifetime. Returns the error that occurred.
func (c *APIClient) PostJSON(
// PostJSON implements APIClient.PostJSON.
func (c *apiClient) PostJSON(
ctx context.Context, resourcePath string, input, output interface{}) error {
request, err := c.newRequestWithJSONBody(ctx, "POST", resourcePath, nil, input)
if err != nil {
@ -154,8 +210,8 @@ func (c *APIClient) PostJSON(
return c.doJSON(request, output)
}
// FetchResource fetches the specified resource and returns it.
func (c *APIClient) FetchResource(ctx context.Context, URLPath string) ([]byte, error) {
// FetchResource implements APIClient.FetchResource.
func (c *apiClient) FetchResource(ctx context.Context, URLPath string) ([]byte, error) {
request, err := c.newRequest(ctx, "GET", URLPath, nil, nil)
if err != nil {
return nil, err

52
internal/engine/httpx/httpx_test.go
View File

@ -11,12 +11,52 @@ import (
"testing"
"github.com/apex/log"
"github.com/ooni/probe-cli/v3/internal/model"
)
const userAgent = "miniooni/0.1.0-dev"
func newClient() *APIClient {
return &APIClient{
func TestAPIClientTemplate(t *testing.T) {
t.Run("normal constructor", func(t *testing.T) {
// TODO(bassosimone): we need to use fakeFiller here
tmpl := &APIClientTemplate{
Accept: "application/json",
Authorization: "ORIG-TOKEN",
BaseURL: "https://ams-pg.ooni.org/",
HTTPClient: http.DefaultClient,
Host: "ams-pg.ooni.org",
Logger: model.DiscardLogger,
UserAgent: userAgent,
}
ac := tmpl.Build()
if ac == nil {
t.Fatal("expected non-nil Client here")
}
})
t.Run("constructor with authorization", func(t *testing.T) {
// TODO(bassosimone): we need to use fakeFiller here
tmpl := &APIClientTemplate{
Accept: "application/json",
Authorization: "ORIG-TOKEN",
BaseURL: "https://ams-pg.ooni.org/",
HTTPClient: http.DefaultClient,
Host: "ams-pg.ooni.org",
Logger: model.DiscardLogger,
UserAgent: userAgent,
}
ac := tmpl.BuildWithAuthorization("AUTH-TOKEN")
if tmpl.Authorization != "ORIG-TOKEN" {
t.Fatal("invalid template Authorization")
}
if ac.(*apiClient).Authorization != "AUTH-TOKEN" {
t.Fatal("invalid client Authorization")
}
})
}
func newClient() *apiClient {
return &apiClient{
BaseURL: "https://httpbin.org",
HTTPClient: http.DefaultClient,
Logger: log.Log,
@ -271,7 +311,7 @@ func TestCreateJSONFailure(t *testing.T) {
func TestFetchResourceIntegration(t *testing.T) {
log.SetLevel(log.DebugLevel)
ctx := context.Background()
data, err := (&APIClient{
data, err := (&apiClient{
BaseURL: "http://facebook.com/",
HTTPClient: http.DefaultClient,
Logger: log.Log,
@ -289,7 +329,7 @@ func TestFetchResourceExpiredContext(t *testing.T) {
log.SetLevel(log.DebugLevel)
ctx, cancel := context.WithCancel(context.Background())
cancel()
data, err := (&APIClient{
data, err := (&apiClient{
BaseURL: "http://facebook.com/",
HTTPClient: http.DefaultClient,
Logger: log.Log,
@ -306,7 +346,7 @@ func TestFetchResourceExpiredContext(t *testing.T) {
func TestFetchResourceInvalidURL(t *testing.T) {
log.SetLevel(log.DebugLevel)
ctx := context.Background()
data, err := (&APIClient{
data, err := (&apiClient{
BaseURL: "http://\t/",
HTTPClient: http.DefaultClient,
Logger: log.Log,
@ -329,7 +369,7 @@ func TestFetchResource400(t *testing.T) {
defer server.Close()
log.SetLevel(log.DebugLevel)
ctx := context.Background()
data, err := (&APIClient{
data, err := (&apiClient{
Authorization: "foobar",
BaseURL: server.URL,
HTTPClient: http.DefaultClient,

2
internal/engine/probeservices/bouncer.go
View File

@ -9,6 +9,6 @@ import (
// GetTestHelpers is like GetCollectors but for test helpers.
func (c Client) GetTestHelpers(
ctx context.Context) (output map[string][]model.OOAPIService, err error) {
err = c.APIClient.GetJSON(ctx, "/api/v1/test-helpers", &output)
err = c.APIClientTemplate.Build().GetJSON(ctx, "/api/v1/test-helpers", &output)
return
}

2
internal/engine/probeservices/checkin.go
View File

@ -16,7 +16,7 @@ type checkInResult struct {
// Returns the list of tests to run and the URLs, on success, or an explanatory error, in case of failure.
func (c Client) CheckIn(ctx context.Context, config model.OOAPICheckInConfig) (*model.OOAPICheckInInfo, error) {
var response checkInResult
if err := c.APIClient.PostJSON(ctx, "/api/v1/check-in", config, &response); err != nil {
if err := c.APIClientTemplate.Build().PostJSON(ctx, "/api/v1/check-in", config, &response); err != nil {
return nil, err
}
return &response.Tests, nil

4
internal/engine/probeservices/checkreportid.go
View File

@ -16,12 +16,12 @@ func (c Client) CheckReportID(ctx context.Context, reportID string) (bool, error
query := url.Values{}
query.Add("report_id", reportID)
var response checkReportIDResponse
err := (&httpx.APIClient{
err := (&httpx.APIClientTemplate{
BaseURL: c.BaseURL,
HTTPClient: c.HTTPClient,
Logger: c.Logger,
UserAgent: c.UserAgent,
}).GetJSONWithQuery(ctx, "/api/_/check_report_id", query, &response)
}).Build().GetJSONWithQuery(ctx, "/api/_/check_report_id", query, &response)
if err != nil {
return false, err
}

4
internal/engine/probeservices/checkreportid_test.go
View File

@ -15,7 +15,7 @@ import (
func TestCheckReportIDWorkingAsIntended(t *testing.T) {
client := probeservices.Client{
APIClient: httpx.APIClient{
APIClientTemplate: httpx.APIClientTemplate{
BaseURL: "https://ams-pg.ooni.org/",
HTTPClient: http.DefaultClient,
Logger: log.Log,
@ -38,7 +38,7 @@ func TestCheckReportIDWorkingAsIntended(t *testing.T) {
func TestCheckReportIDWorkingWithCancelledContext(t *testing.T) {
client := probeservices.Client{
APIClient: httpx.APIClient{
APIClientTemplate: httpx.APIClientTemplate{
BaseURL: "https://ams-pg.ooni.org/",
HTTPClient: http.DefaultClient,
Logger: log.Log,

4
internal/engine/probeservices/collector.go
View File

@ -105,7 +105,7 @@ func (c Client) OpenReport(ctx context.Context, rt ReportTemplate) (ReportChanne
return nil, ErrUnsupportedFormat
}
var cor collectorOpenResponse
if err := c.APIClient.PostJSON(ctx, "/report", rt, &cor); err != nil {
if err := c.APIClientTemplate.Build().PostJSON(ctx, "/report", rt, &cor); err != nil {
return nil, err
}
for _, format := range cor.SupportedFormats {
@ -144,7 +144,7 @@ func (r reportChan) CanSubmit(m *model.Measurement) bool {
func (r reportChan) SubmitMeasurement(ctx context.Context, m *model.Measurement) error {
var updateResponse collectorUpdateResponse
m.ReportID = r.ID
err := r.client.APIClient.PostJSON(
err := r.client.APIClientTemplate.Build().PostJSON(
ctx, fmt.Sprintf("/report/%s", r.ID), collectorUpdateRequest{
Format: "json",
Content: m,

3
internal/engine/probeservices/login.go
View File

@ -29,7 +29,8 @@ func (c Client) MaybeLogin(ctx context.Context) error {
}
c.LoginCalls.Add(1)
var auth LoginAuth
if err := c.APIClient.PostJSON(ctx, "/api/v1/login", *creds, &auth); err != nil {
if err := c.APIClientTemplate.Build().PostJSON(
ctx, "/api/v1/login", *creds, &auth); err != nil {
return err
}
state.Expire = auth.Expire

4
internal/engine/probeservices/measurementmeta.go
View File

@ -54,12 +54,12 @@ func (c Client) GetMeasurementMeta(
query.Add("full", "true")
}
var response MeasurementMeta
err := (&httpx.APIClient{
err := (&httpx.APIClientTemplate{
BaseURL: c.BaseURL,
HTTPClient: c.HTTPClient,
Logger: c.Logger,
UserAgent: c.UserAgent,
}).GetJSONWithQuery(ctx, "/api/v1/measurement_meta", query, &response)
}).Build().GetJSONWithQuery(ctx, "/api/v1/measurement_meta", query, &response)
if err != nil {
return nil, err
}

4
internal/engine/probeservices/measurementmeta_test.go
View File

@ -16,7 +16,7 @@ import (
func TestGetMeasurementMetaWorkingAsIntended(t *testing.T) {
client := probeservices.Client{
APIClient: httpx.APIClient{
APIClientTemplate: httpx.APIClientTemplate{
BaseURL: "https://ams-pg.ooni.org/",
HTTPClient: http.DefaultClient,
Logger: log.Log,
@ -84,7 +84,7 @@ func TestGetMeasurementMetaWorkingAsIntended(t *testing.T) {
func TestGetMeasurementMetaWorkingWithCancelledContext(t *testing.T) {
client := probeservices.Client{
APIClient: httpx.APIClient{
APIClientTemplate: httpx.APIClientTemplate{
BaseURL: "https://ams-pg.ooni.org/",
HTTPClient: http.DefaultClient,
Logger: log.Log,

6
internal/engine/probeservices/probeservices.go
View File

@ -65,7 +65,7 @@ type Session interface {
// Client is a client for the OONI probe services API.
type Client struct {
httpx.APIClient
httpx.APIClientTemplate
LoginCalls *atomicx.Int64
RegisterCalls *atomicx.Int64
StateFile StateFile
@ -91,7 +91,7 @@ func (c Client) GetCredsAndAuth() (*LoginCredentials, *LoginAuth, error) {
// function fails, e.g., we don't support the specified endpoint.
func NewClient(sess Session, endpoint model.OOAPIService) (*Client, error) {
client := &Client{
APIClient: httpx.APIClient{
APIClientTemplate: httpx.APIClientTemplate{
BaseURL: endpoint.Address,
HTTPClient: sess.DefaultHTTPClient(),
Logger: sess.Logger(),
@ -115,7 +115,7 @@ func NewClient(sess Session, endpoint model.OOAPIService) (*Client, error) {
if URL.Scheme != "https" || URL.Host != URL.Hostname() {
return nil, ErrUnsupportedCloudFrontAddress
}
client.APIClient.Host = URL.Hostname()
client.APIClientTemplate.Host = URL.Hostname()
URL.Host = endpoint.Front
client.BaseURL = URL.String()
if _, err := url.Parse(client.BaseURL); err != nil {

6
internal/engine/probeservices/psiphon.go
View File

@ -11,9 +11,7 @@ func (c Client) FetchPsiphonConfig(ctx context.Context) ([]byte, error) {
if err != nil {
return nil, err
}
// Note: the following code is very bad: it copies the original
// API client and then overrides one of its fields. Bleah...
client := c.APIClient
client.Authorization = fmt.Sprintf("Bearer %s", auth.Token)
s := fmt.Sprintf("Bearer %s", auth.Token)
client := c.APIClientTemplate.BuildWithAuthorization(s)
return client.FetchResource(ctx, "/api/v1/test-list/psiphon-config")
}

3
internal/engine/probeservices/register.go
View File

@ -33,7 +33,8 @@ func (c Client) MaybeRegister(ctx context.Context, metadata Metadata) error {
Password: pwd,
}
var resp registerResult
if err := c.APIClient.PostJSON(ctx, "/api/v1/register", req, &resp); err != nil {
if err := c.APIClientTemplate.Build().PostJSON(
ctx, "/api/v1/register", req, &resp); err != nil {
return err
}
state.ClientID = resp.ClientID

6
internal/engine/probeservices/tor.go
View File

@ -14,10 +14,8 @@ func (c Client) FetchTorTargets(ctx context.Context, cc string) (result map[stri
if err != nil {
return nil, err
}
// Note: the following code is very bad: it copies the original
// API client and then overrides one of its fields. Bleah...
client := c.APIClient
client.Authorization = fmt.Sprintf("Bearer %s", auth.Token)
s := fmt.Sprintf("Bearer %s", auth.Token)
client := c.APIClientTemplate.BuildWithAuthorization(s)
query := url.Values{}
query.Add("country_code", cc)
err = client.GetJSONWithQuery(

3
internal/engine/probeservices/urls.go
View File

@ -28,7 +28,8 @@ func (c Client) FetchURLList(ctx context.Context, config model.OOAPIURLListConfi
query.Set("category_codes", strings.Join(config.Categories, ","))
}
var response urlListResult
err := c.APIClient.GetJSONWithQuery(ctx, "/api/v1/test-list/urls", query, &response)
err := c.APIClientTemplate.Build().GetJSONWithQuery(ctx,
"/api/v1/test-list/urls", query, &response)
if err != nil {
return nil, err
}