Deno: Folder write permission is spuriously requested when loading a package about pyodide HOT 6 CLOSED

when loading a package even for packages that don't need to be downloaded.

The package numpy is a part of the default distribution.

No. This is not true. NumPy is not included in the default distribution. Actually, we don't include any wheels in the npm package to reduce the size of the npm Pyodide package. Check the node_modules/pyodide directory.

Instead, we download packages on the fly in Node.js and store them in the node_modules directory (Code Pointer). So I guess that's why Deno is requesting a write access.

This is not an ideal situation, but we don't want to host hundreds of megabytes of packages in a single npm package.

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@ryanking13 Oh, right, don't know why I thought numpy was included, it's indeed cached in the node_modules folder.

But the point still stands -- even when no changes are needed, write access is requested, which does not make sense.

I think the culprit is some needless mkdir, given that the request is for Deno.mkdir. Most likely there's some code that creates a folder in order to ensure that the folder exists, which prompts for the write permission.

Eg. something like this:

create_folder(folder)
do_something_with_folder(folder)

...should be changed into this

if not exists(folder):
  create_folder(folder)
do_something_with_folder(folder)

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@ryanking13 I found the offending line:

Patching it out fixes the problem:

Adding a check here if the folder exists would prevent Deno from needlessly asking for permission. Sorry for not sending a full PR, I'm not very proficient with Node.js

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Oh, I see. That makes sense. Thanks for the detailed information @JanPokorny! I'll see if I can fix it by checking the existence of the path first.

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Fixed by @whitphx #4738.

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That's great, thank you @whitphx !

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