Being able to do `import(blobUrls)`

[jimmywarting]

What is the problem this feature will solve?

tried doing:

code = 'console.log("hi")'
blob = new Blob([code], { type: 'text/javascript' })
url = URL.createObjectURL(blob)
import(url)

but failed with:

Only URLs with a scheme in: file and data are supported by the default ESM loader. Received protocol 'blob:'

What is the feature you are proposing to solve the problem?

being able to import dynamic generated code...

What alternatives have you considered?

converting it to a data: url works as a work around...

[bnoordhuis]

Does importing a blob work in other JS runtimes? It doesn't seem to in Firefox. Are there WPT tests that cover this?

[bnoordhuis]

Are there WPT tests that cover this?

To answer my own question: yes, there are

[jimmywarting]

Does importing a blob work in other JS runtimes?

Yes... i have done it many times in browsers to create dynamic code that i then import...

there are many other developer who dose this too. things like sql.js and JSZip think both are creating a hybrid solution that takes it's own minified source code and create a separate thread in order to not block havy calculations.

kinda like:

function ctx() { ... }
const blob = blob([ctx.toString(), `${ctx.name}()`])
const url = URL.createObjectURL(blob)

import(url)
new Worker(url)

works OK, as long as the function is "pure" and don't references any variable outside of it's own function
But i guess it's a bit unusual to do: import(blobURL) then to create dynamic web workers.

JSFiddle and other code playgrounds certainly benefit of using import(blobUrl) if there is code that uses import x from xyz syntax

---

I just worked around this issue in my web worker polyfill
I created a custom loader and basically run NodeJS with: node --loader ./resolver.js app.js

And b/c blob urls are not working via cross threads: #46557
then i had to resort to using BroadcastChannel to request all threads if they have any references to those blobs.

so i guess ☝️ is a blocker...

[jimmywarting]

I could add to that i would also like to be able to do:

const url = URL.createObjectURL(blob)
new worker_threads.Worker(url, { type: 'module' })

but that maybe will be a own issue in itself...

[github-actions]

There has been no activity on this feature request for 5 months and it is unlikely to be implemented. It will be closed 6 months after the last non-automated comment.

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[github-actions]

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For more information on how the project manages feature requests, please consult the feature request management document.