Replicating @babel/template functionality

[lewisl9029]

Hi there!

I have a custom babel plugin that currently uses the @babel/template package to inject blocks of code into files without breaking sourcemaps. A vastly simplified version looks something like this:

const createPlugin = () => {
  // The console.logs are just placeholders, the actual code is quite long
  // I'd like to avoid manually rewriting into ASTs if possible
  const beforeAst = babelTemplate.ast(`console.log('hi!')`)

  const afterAst = babelTemplate.ast(`console.log('bye!')`)

  return () => ({
    visitor: {
      Program: {
        exit: (path) => {
          path.unshiftContainer('body', beforeAst)
          path.pushContainer('body', afterAst)
        },
      },
    },
  })
}

I'd love to migrate it over to swc for those sweet performance gains, but after looking through the docs, I'm still unsure how I could accomplish the same task.

Any assistance would be very much appreciated!

[kdy1]

Alternative for @babel/template is WIP.

[lewisl9029]

That's amazing! Thank you so much!

Just found the PR here for anyone else who might be looking for it: #3155

Will follow along!

[bryanjtc]

What is the status of the alternative? I see that #3155 was merged, but no mention of how to replace @babel/template with swc in any of the docs.

[kdy1]

See https://rustdoc.swc.rs/swc_ecma_quote/macro.quote.html for usage

[redexp]

@kdy1 quote! is looks like replacement for babel template, but it can handle only one expression. It could be full replacement if quote handle full Module not just ModuleItem.