api/v2: send empty route lists under fields=all

hscontrol/api/v2/devices.go

@@ -46,9 +46,9 @@ type Device struct {
 	// does not record, so it is left out.
 	OAuthClientID string `json:"oauthClientId,omitempty"`
 
-	// Populated only when fields=all is requested.
-	AdvertisedRoutes []string `json:"advertisedRoutes,omitempty"`
-	EnabledRoutes    []string `json:"enabledRoutes,omitempty"`
+	// Populated only when fields=all is requested, then as [] when empty.
+	AdvertisedRoutes []string `json:"advertisedRoutes,omitzero"`
+	EnabledRoutes    []string `json:"enabledRoutes,omitzero"`
 }
 
 // DeviceRoutes is the GET /device/{id}/routes response: what the node announces

hscontrol/apiv2_compat_test.go

@@ -99,14 +99,6 @@ var apiv2CompatSkipReasons = map[string]string{
 	"oauth/device:before/all/device-oauth-client": deviceOAuthClientMaker,
 	"oauth/device:joiner/all/device-oauth-client": deviceOAuthClientMaker,
 
-	"oauth/device:before/empty-route-lists":    emptyRouteListsOmitted,
-	"oauth/device:ci-runner/empty-route-lists": emptyRouteListsOmitted,
-	"oauth/device:joiner/empty-route-lists":    emptyRouteListsOmitted,
-	"oauth/device:laptop/empty-route-lists":    emptyRouteListsOmitted,
-	"oauth/device:managed/empty-route-lists":   emptyRouteListsOmitted,
-	"oauth/device:mixed/empty-route-lists":     emptyRouteListsOmitted,
-	"oauth/device:prod-db/empty-route-lists":   emptyRouteListsOmitted,
-
 	"policy-api/P7/0/body": hujsonFormatted,
 	"policy-api/P7/1/body": hujsonFormatted,
 }
@@ -154,7 +146,6 @@ const (
 	deletedClientGone           = "DELETED_CLIENT_GONE: SaaS keeps a deleted OAuth client readable as invalid and revoked; headscale removes it"
 	deletedClientCredentialText = "DELETED_CLIENT_CREDENTIAL_TEXT: SaaS refuses a deleted client's secret and tokens with API token invalid; headscale says invalid client credentials and unauthorized"
 	missingScopeText            = "MISSING_SCOPE_TEXT: SaaS refuses a delete outside the token's scopes with calling actor does not have enough permissions; headscale names the missing scope"
-	emptyRouteListsOmitted      = "EMPTY_ROUTE_LISTS_OMITTED: SaaS sends advertisedRoutes and enabledRoutes as [] for a device without routes under fields=all; headscale leaves both out"
 	hujsonFormatted             = "HUJSON_FORMATTED: SaaS stores a HuJSON policy formatted, comments kept; headscale stores the bytes as sent"
 )
 

hscontrol/apiv2_devices_test.go

@@ -151,6 +151,22 @@ func TestAPIv2Device_Get(t *testing.T) {
 	assert.Equal(t, n.IPsAsString(), dev.Addresses)
 }
 
+// TestAPIv2Device_EmptyRouteLists: fields=all sends a device's route lists
+// even when they are empty; the default read leaves them out.
+func TestAPIv2Device_EmptyRouteLists(t *testing.T) {
+	e := newDeviceTestEnv(t)
+
+	all := e.api.Get("/api/v2/device/" + e.deviceID + "?fields=all")
+	require.Equalf(t, http.StatusOK, all.Code, "body: %s", all.Body)
+	assert.Contains(t, all.Body.String(), `"advertisedRoutes":[]`)
+	assert.Contains(t, all.Body.String(), `"enabledRoutes":[]`)
+
+	def := e.api.Get("/api/v2/device/" + e.deviceID)
+	require.Equalf(t, http.StatusOK, def.Code, "body: %s", def.Body)
+	assert.NotContains(t, def.Body.String(), "advertisedRoutes")
+	assert.NotContains(t, def.Body.String(), "enabledRoutes")
+}
+
 // TestAPIv2Device_NameIsFQDN: with a base domain, a device's name is its
 // MagicDNS FQDN, in a read and in the list.
 func TestAPIv2Device_NameIsFQDN(t *testing.T) {