Cannot find module 'assemblyscript/asc' or its corresponding type declarations.

[bbrk24]

The website says it's possible to call asc programmatically in JavaScript, and can be imported as follows:

import asc from "assemblyscript/asc";

Source: Programmatic usage

However, trying to do so in TypeScript fails with the error message from the title. There is no @types/assemblyscript package either, at least not that yarn can find.

TypeScript seems to think the module is called assemblyscript/dist/asc, as I can import that with no such error.

[bbrk24]

If I ignore the errors and run it in JavaScript anyways, Node gives me the error Error [ERR_PACKAGE_PATH_NOT_EXPORTED]: Package subpath './asc' is not defined by "exports" in C:\Users\[...]\node_modules\assemblyscript\package.json. I tried it in Node v16 and v17, but they both give me the same error. However, I definitely see it in the package.json, so I'm not really sure what's up.

[dcodeIO]

This is a relatively recent change (in v0.20). What's the version of the compiler you are using?

[bbrk24]

@dcodeIO I have version 0.20.2 installed.

[dcodeIO]

Toying around with this a little, seems the import can be resolved when adding "moduleResolution": "NodeNext" to tsconfig.json. However, there's a new error then on

import asc from "assemblyscript/asc";

stating

Module 'assemblyscript/asc' cannot be imported using this construct. The specifier only resolves
to an ES module, which cannot be imported synchronously. Use dynamic import instead.ts(1471)

which seems just as odd, as it doesn't go away even when adding "target": "ESNext" and "module": "NodeNext".

There is another hint, however, stating

Compiler option 'module' of value 'nodenext' is unstable. Use nightly TypeScript to silence this error.
Try updating with 'npm install -D typescript@next'.ts

which I haven't tested. Perhaps it's simply not supported by stable TS yet?

[bbrk24]

That's unfortunate. I didn't realize it was ESM-only; I'm using CommonJS for imports, so that's probably why it's broken.

[bbrk24]

@dcodeIO I got it to work in TypeScript 4.5.5 by using --module ES2022 --moduleResolution node, but I have to import assemblyscript/dist/asc.js rather than just assemblyscript/asc.

[bbrk24]

I am seeing very strange behavior when I do this. For example, the following code logs out several megabytes, mostly base-64-encoded data:

import asc from "assemblyscript/dist/asc.js";
throw new Error();

[dcodeIO]

I believe that's because Node.js by default doesn't load source maps, and somehow believes that printing all minified code on the same line is of great use. Could also be connected to Binaryen's Emscripten output, not sure, so perhaps not Node. Nonetheless, providing --enable-source-maps to the Node.js invocation should yield a proper error, i.e.:

assemblyscript/package.json

Line 71 in 9c0db25

"test:browser": "node --enable-source-maps tests/browser",

[bbrk24]

Yep, --enable-source-maps helped. Still, the original issue (that I have to use a different import path than documented) stands.

[dcodeIO]

My intuition here is that, when it works in plain JS, this would be an incompatibility of TS with Node's new exports field. Would assume that the TS folks are already working on it, but hard to say for sure. Does it perhaps work with typescript@next, as the warning above recommends?

[bbrk24]

@dcodeIO No, but I currently can't compile at all with typescript@next, due to a compilation error in node_modules/typescript/lib/typescript.d.ts. I've filed an issue at microsoft/TypeScript#48504.

[jerrygreen]

Before trying Typescript just try to import it from js for starters. I'm getting Cannot find module error with just pure js (when trying to import dist files).

At least I'm using Node v14.15.2, but you seem to stuck into the similar thing with v16-17 too, so I guess it's not the Node version.

[bbrk24]

@jerrygreen I couldn't import it from the Node REPL or a commonjs script. I had to either save it as a .mjs file or put "type": "module" in package.json. Even then, I'm using Node 17.