bombillazo•15mo ago

How can one patch a Deno dependency?

Hello, We're used to working with node and using patch-package to override and fix packages fairly easily. However, we're now using Deno due to using Supabase edge functions and have not figure a way to get the same dev experience. Is there any guide or way one can patch a dependency in Deno?

6 Replies

Mark G•15mo ago

You can use import maps to map pretty much any module URL, lets say for example you want to use 0.200.0 of std lib everywhere, but some libs are using an older version, say 0.192.0, you can add this into your import map:

"imports": {
  "https://deno.land/std@0.192.0/": "https://deno.land/std@0.200.0/"
}

"imports": {
  "https://deno.land/std@0.192.0/": "https://deno.land/std@0.200.0/"
}

can also target individual modules, eg:

"imports": {
  "https://deno.land/std@0.161.0/encoding/base64.ts": "https://deno.land/std@0.200.0/encoding/base64.ts"
}

"imports": {
  "https://deno.land/std@0.161.0/encoding/base64.ts": "https://deno.land/std@0.200.0/encoding/base64.ts"
}

Mark G•15mo ago

you can also use "scopes" in the import map to limit the scope of the mapping too... https://github.com/WICG/import-maps#scoping-examples ... although I've never needed to resort to this

GitHub

GitHub - WICG/import-maps: How to control the behavior of JavaScrip...

How to control the behavior of JavaScript imports. Contribute to WICG/import-maps development by creating an account on GitHub.

Mark G•15mo ago

oh, you mentioned patching though, in which case if you want to override a library module with a local one you can do that too...

  "https://blahblah/foo/iffy-module.ts": "./patched/iffy-module.ts"

  "https://blahblah/foo/iffy-module.ts": "./patched/iffy-module.ts"

bombillazoOP•15mo ago

Hey, thanks for the info! So if I use an import_map.json and set a imports key to another version, all depedencies and sub dependencis that use the original verison will now point to the new one? Ok I guess I can answer my own question: yes hence the need/use of "scopes"

Leokuma•15mo ago

Also have a look at the command deno vendor. It downloads all deps into a folder

bombillazoOP•15mo ago

Thanks! I ended up using deno vendor to pull the deps into a folder then using that to create our patched version and import it locally. 😁