Support Jiti (unjs)

[birkskyum]

Jiti - GitHub

Platform

Darwin 22.6.0 arm64 arm

Version

deno 1.37.0

Repro

// import console from "node:console";
let sum = 2+2;
console.log(`2+2 = ${sum}`);
console.log("Print this");

Expected

This output:

2+2 = 4
Print this

Actual

➜ deno run -A npm:jiti index.ts
error: Uncaught TypeError: Cannot read properties of undefined (reading 'log')
    at data::3:9
    at data::5:4
    at evalModule (file:///Users/admin/Library/Caches/deno/npm/registry.npmjs.org/jiti/1.19.3/dist/jiti.js:1:255456)
    at jiti (file:///Users/admin/Library/Caches/deno/npm/registry.npmjs.org/jiti/1.19.3/dist/jiti.js:1:253384)
    at Object.<anonymous> (file:///Users/admin/Library/Caches/deno/npm/registry.npmjs.org/jiti/1.19.3/bin/jiti.js:15:1)
    at Object.<anonymous> (file:///Users/admin/Library/Caches/deno/npm/registry.npmjs.org/jiti/1.19.3/bin/jiti.js:17:4)
    at Module._compile (node:module:733:34)
    at Object.Module._extensions..js (node:module:747:10)
    at Module.load (node:module:658:32)
    at Function.Module._load (node:module:539:12)
    at Object.loadCjsModule (ext:deno_node/02_init.js:52:22)
    at loadCjsModule ([ext:ext/node/lib.rs:595:29]:2:32)
    at [ext:ext/node/lib.rs:595:29]:3:7

Additional info

This works if importing node:console

[bartlomieju]

Did some digging into it - what Jiti is doing is wrapping the provided code using Module.wrap and evaluating it using Script.runInThisContext, resulting in:

(function (exports, require, module, __filename, __dirname, Buffer, clearImmediate, clearInterval, clearTimeout, console, global, process, setImmediate, setInterval, setTimeout, performance) { (function (exports, require, module, __filename, __dirname) {"use strict";
let sum = 2 + 2;
console.log(`2+2 = ${sum}`);
console.log("Print this"); /* v7-ff3385c374396619 */
}).call(this, exports, require, module, __filename, __dirname); })

The problem is that after this wrapping, this function is evaluated directly and that causes the wrapper to miss some variables (everything after Buffer). We need to explicitly provide these variables somehow. The problem is that it's not guaranteed that every call to Script.runInThisContext will use Module.wrap, so we can't unconditionally bind variables.

[birkskyum]

As @pi0 mentioned here, it might be necessary with an adapter to get this working, since Deno doesn't support the .cjs and thus can't skip jiti entirely the same way Bun does.

[bartlomieju]

That's for floating the link @birkskyum, I will try to fix it (need to refresh my memory on the details of vm module); maybe we don't need to change anything in jiti after all. We have mechanisms to execute CommonJS, it's just they are not exposed to user code (but npm packages can use these mechanisms).

[birkskyum]

Ah, interesting. If possible, that does sound like the better approach, because I doubt people would adopt Deno for Nuxt development if the transformer solution made the dx slower.

[pi0]

Thanks for following up on this @bartlomieju @birkskyum ❤️ Please let me know if could help on this (i am reachable via pi0 in discord as well).

[birkskyum]

@littledivy , just tried this with the latest canary (fad12b7). I still see the same error:

error: Uncaught TypeError: Cannot read properties of undefined (reading 'log')

[birkskyum]

I was curious to see if BYONM helped here, so I tried running this with latest deno 1.45.5 and DENO_FUTURE=1 deno task dev which executed jiti index.ts in package.json, but it gives the same output.

[birkskyum]

This appear to work with the deno 2.0.0-rc.2+aaf2bf4

[pi0]

Right before jiti v2 release, we will use a fast path for Deno (similar to Bun), still impressive how Deno Node.js compatibility had been improved. ❤️