json and html is not bundle

As node official website suggested to use fs module to load json file, but esbuild is not bundling the .json and .html extension.

https://nodejs.org/api/esm.html#esm_no_json_module_loading

// lambda throws "Runtime.UnhandledPromiseRejection: TypeError [ERR_INVALID_URL]: Invalid URL: ./jsonSchema.json"
import { readFile } from 'fs/promises';
const jsonSchema = JSON.parse(await readFile(new URL('./jsonSchema.json', import.meta.url)));

// this work correctly in lambda, but mocha throws TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".json"
import jsonSchema from './jsonSchema.json';

is there a way to use recommended way to bundle .json and .html files? i set the loader option but it is not working

  esbuild:
    bundle: true
    minify: true
    sourcemap: true
    keepNames: true
    loader:
      .html: text
      .json: text

[jefftham]

Hi @jweyrich , thanks for your response. Actually, serverless-esbuild work as expected to bundle the file. The main issue is that we cannot test the source code because no esbuild-register created for js. There is one for typescript.

Yes, you solution may be work provided the it is a typescript project.

[jefftham]

FYI, i have spent enough of time to find the possible solutions. Now i got it and happy to share.

Background:-

• esbuild work correctly to import json and bundle it.
• esbuild work correctly to import html and bundle it if we define it in serverless.yml as custom.esbuild.loader..html =text
• mocha should test on the source code instead of compiled code but node or mocha do not know what is going on with esbuild.

Solution:-

• import json is an unsupport/experimental feature, we can turn it on for nodejs or mocha. eg. --experimental-json-modules
• import html is not support natively but we can use custom loader to achieve it. eg. --experimental-loader=./loader.js, ref to https://dev.to/valeriavg/how-to-use-custom-files-as-modules-in-nodejs-51lp
• It is difficult to pass these args to mocha, the trick is to use node-option in the mocharc file.

node-option: - 'no-warnings=ExperimentalWarning' - 'experimental-json-modules' - 'experimental-loader=./loader.js'