Summary

Searching for q = '<email>' in writers should return "Files for which user <email> has write permission", according to the Drive API docs. This does not work for files shared in a Shared Drive. The files will only show up if they are explicitly shared with writer permissions using the normal sharing workflow.

Reproduction Steps:

1. Create a shared drive.
2. Create a document in that shared drive with an easily identifiable name i.e. "202010 Drive API File List query test"
3. Go to https://developers.google.com/drive/api/v3/reference/files/list
4. Use the API explorer to make a request with these parameters:

corpora = allDrives
includeItemsFromAllDrives = true
q = '<email>' in writers
supportsAllDrives = true

5. Send the request.

Expected Behavior:

The document "202010 Drive API File List query test" should be in the response.

Actual Behavior:

The document is omitted.

Workarounds:

1. List all files with limited fields and filter client side using the 'files/capabilities/canEdit' field.
2. Make requests to all shared drives which you have write capability in conjunction with another request q = '<email>' in writers in main drive.

This issue report has been forwarded to the Drive engineering team so that they may investigate it, but there is no ETA for a resolution at this time. Future updates regarding this issue will be provided here.