これは私が使用するものです
function getUserRoles(webUrl,accountName)
{
return getUserEffectivePermissions(webUrl,accountName).then(function(data){
var permissions = new SP.BasePermissions();
permissions.initPropertiesFromJson(data);
var permLevels = [];
for(var permLevelName in SP.PermissionKind.prototype) {
if (SP.PermissionKind.hasOwnProperty(permLevelName)) {
var permLevel = SP.PermissionKind.parse(permLevelName);
if(permissions.has(permLevel)){
permLevels.push(permLevelName);
}
}
}
return permLevels;
});
}