ESM fix for node 14.13.1 breaking change

[cspotcode]

Pretty sure it's cuz the URL protocol for native modules changed from nodejs: to node: and has to do with our necessary forking of node's resolver.

Fix must:

• be backwards compatible (at least in the short-term). Before 14.13.1 needs to use nodejs:; after needs to use node:
• test suite updated to run 14.13.0 and 14.13.1 (or at least one 14.x version before and one after)
• specs should attempt to load native modules without import elision

Relevant conversation starts here: #1007 (comment)

[cspotcode]

Maybe node: vs nodejs: can be feature-detected the first time our resolve implementation is called. defaultResolve('node:fs') and look at what it gives us.

[concision]

If anyone needs a quick fix (as the linked PR has not been released on npm), experimentally this solution seems to work by early deferring Node.js builtin modules (i.e. null specifier). Might not work in 100% of scenarios - your mileage may vary.

Create a new file ts-node-esm-loader-fix.mjs and set the ESM loader to it (e.g. --loader=./ts-node-esm-loader-fix.mjs):

import url from "url";

// initialize ts-node ESM loader; promise to early initialize
const esmLoader = new Promise(async (resolve, reject) => {
 try {
 resolve(await import("ts-node/esm.mjs"));
 } catch (error) {
 reject(error);
 }
});

// delegate to ts-node ESM loader
export async function resolve(specifier, context, defaultResolve) {
 // resolves change from 'nodejs:' to 'node:'
 if (url.parse(specifier).protocol === null) return defaultResolve(...arguments);
 return (await esmLoader).resolve(...arguments);
}
export async function getFormat() {
 return (await esmLoader).getFormat(...arguments);
}
export async function transformSource() {
 return (await esmLoader).transformSource(...arguments);
}

[cspotcode]

Over the weekend I merged a fix to master, so this should already be fixed on master.

…

On Thu, Nov 5, 2020, 1:46 AM concision ***@***.***> wrote: If anyone needs a quick fix, experimentally this solution seems to work by early deferring Node.js builtin modules (i.e. null specifier). Might not work in 100% of scenarios - your mileage may vary. Create a new file ts-node-esm-fix.mjs and set the ESM loader to it (e.g. --loader=./ts-node-fix.mjs): import url from "url"; // initialize ts-node ESM loader; promise to early initializeconst esmLoader = new Promise(async (resolve, reject) => { try { resolve(await import("ts-node/esm.mjs")); } catch (error) { reject(error); }}); // delegate to ts-node ESM loaderexport async function resolve(specifier, context, defaultResolve) { // resolves change from 'nodejs:' to 'node:' if (url.parse(specifier).protocol === null) return defaultResolve(...arguments); return (await esmLoader).resolve(...arguments);}export async function getFormat() { return (await esmLoader).getFormat(...arguments);}export async function transformSource() { return (await esmLoader).transformSource(...arguments);} — You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub <#1130 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAC35OGETJA6EP2BB2Q4V7DSOJC4TANCNFSM4SL67DRA> .

[cspotcode]

Npm can install ts-node directly from github instead of npmjs.com, allowing you to use the latest code from master.

[concision]

Ah, I did not realize that npm/yarn will build a module directly from GitHub! Thanks for letting me know! And thank you for your work on ts-node! :)