Adding file locations to templates

[KonnorRogers]

I'm not quite sure where to put this, but previously in EJS I had a fileLoader hook for adding "preambles" and "postambles" to file renderings. Does nunjucks have an equivalent?

EJS:

import ejs from "ejs"

let ejsFileLoader = function (filePath: string) {
  const preamble = `<!-- template_start: ${path.relative(getRootDir(), filePath)} -->`
  const postamble = `<!-- template_end: ${path.relative(getRootDir(), filePath)} -->`
  
  return preamble + fs.readFileSync(filePath) + postamble;
};

ejs.fileLoader = ejsFileLoader

The best I came up with for Nunjucks is the following:

const render = nunjucks.render
nunjucks.render = function (file: string, ...args: any[]) {
  const preamble = `<!-- template_start: ${path.relative(getRootDir(), file)} -->`
  const postamble = `<!-- template_end: ${path.relative(getRootDir(), file)} -->`
  
  return preamble + render.call(nunjucks, file, ...args) + postamble
}

but that feels wrong. Am I missing something obvious using the FileLoader or Environment APIs?