Add a helper to generate Blob (lazily read) from a file path

[coyotte508]

Or wait on nodejs/node#45188

This would help for the commit calls, when uploading very large files, to avoid loading the whole file in memory.

Would help with #62

Technical PR.

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Given that it's only needed for Deno & Node (and node should have a native solution soon), it should be an internal helper. We want to be able to remove it at some point.

[Aschen]

I started to look into this and if I understood well the problem, I'm thinking about a solution using Filehandle.read but it will need some change in the code because then slice method need to be async in order to read the desired slice from the file and returning it in a Blob instance.

• here l.103
• here l.235

Also about the usage Blob.length here and here, isn't it an error since it does not exists on the Blob API?

[coyotte508]

Also about the usage Blob.length here and here, isn't it an error since it does not exists on the Blob API?

Thanks! I added a bug fix: b7934a5

I started to look into this and if I understood well the problem, I'm thinking about a solution using Filehandle.read but it will need some change in the code because then slice method need to be async in order to read the desired slice from the file and returning it in a Blob instance.

It should be fine to only do the Filehandle calls when .arrayBuffer() / .text() / .stream() is called. As for .size, if we pass the info to the new blob when creating it, it should be fine as well.

[Aschen]

I suggested a LazyBlob implementation here #104

Feel free to give me any suggestion