Filename with a hash (#) not uploading - microsoft-graph-api

Question

I'm attempting to send a file to OneDrive using the following code:
$uri = "/me/drive/items/$folderId/children('{$fileName}')/content";
$graph = $this->graph->create($user);
$client = $this->graph->createClient();
$item = $graph->createRequest("PUT", $uri)
->attachBody($fileContent)
->setReturnType(Model\DriveItem::class)
->execute($client);
This works great if $fileName is something like Test.doc
But for some reason, when the filename has a hash (#) in the filename, then I get an error:
object(Microsoft\Graph\Model\DriveItem)#1509 (1) {
["_propDict":protected]=>
array(1) {
["error"]=>
array(3) {
["code"]=>
string(10) "BadRequest"
["message"]=>
string(36) "Bad Request - Error in query syntax."
["innerError"]=>
array(2) {
["request-id"]=>
string(36) "ff3fe15f-b1ee-4e92-8abd-2400b1c1b5cf"
["date"]=>
string(19) "2018-10-04T14:30:51"
}
}
}
Can someone possibly clarify if this is a bug or actual behaviour (i.e. you cannot have a # in a filename)
Thanks

Answer 1

I guess you are utilizing Microsoft Graph Library for PHP, special characters such as # needs to be escaped.
So, either replace the hash with %23 (percent encoding) or use rawurlencode function as shown below:
$fileName = rawurlencode("Guide#.docx");
$requestUrl = "https://graph.microsoft.com/v1.0/drives/$driveId/root:/$fileName:/content";
try {
$item = $client->createRequest("PUT", $requestUrl)
->attachBody($fileContent)
->setReturnType(Model\DriveItem::class)
->execute();
} catch (\Microsoft\Graph\Exception\GraphException $ex) {
print $ex;
}

Answer 2

Although the file name have support # in name, but it doesn't mean the Product Team provide the API or adjust the existing API first time, the API you use may not have fully adjusted to suit thore latest naming rules. So it should be actual behavior now but not bug/or you can treat it as none-existed feature.
There are a related issue in the SharePoint dev issue list, although they aren't same one, but the suggestion is the same, vote the exising feature or submit an new one on UserVoice.