async util: handle empty dirs better #3797
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| @@ -389,7 +389,7 @@ def _scandir(future, path, request): | |||
| """Callback helper for scandir().""" | |||
| future.set_result([ | |||
| Path(path, directory.name) | |||
| for directory in request.result | |||
| for directory in request.result or [] | |||
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Why does this make any difference? If I put an empty directory in ~cylc-run then request.result is an empty list already. (And I didn't see an error without this change).
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I saw an error where (request.result was returning None) in the log whilst working on cylc-uiserver so put this in to suppress it.
Perhaps it happens when you scan a non-existent directory or something like that.
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OK, fair enough. Probably needs a comment then, because it looks weird (if you expect request.result to always be list).
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Huh, GitHub let me create a "suggestion" and commit it to the branch 😁
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Brilliant, my comment was a style violation (line too long) 🤣
Just noticed a warning which can occur if
scandirattempts to scan an empty directory.I think this is harmless ATM as the only use of
scandiris workflow scanning, if a workflow dir is empty then it's not a workflow dir so can be safely skipped.Also add a small update post-#3755.