Syntax for Ajv import?

What version of Ajv are you using? Does the issue happen if you use the latest version?

Version 8.11.0, installed today

Ajv options object None.

Your code

// ProjectJSON.mts

// this works, https://github.com/microsoft/TypeScript/issues/24847}
import { default as Ajv } from "ajv";

// this doesn't work, but is the currently recommended import line
//import Ajv from "ajv";
/*
_02_passthrough_types/source/ProjectJSON.mts(98,17): error TS2351: This expression is not constructable.
  Type 'typeof import("/home/ajvincent/code-generation/cross-stitch/node_modules/ajv/dist/ajv")' has no construct signatures.
*/
const ajv = new Ajv();
void(ajv);

I was bitten on this exact error with https://github.com/dsherret/code-block-writer/issues/42 a few weeks ago.

Are you going to resolve the issue?

I can, by adding a little bit of documentation. I just need to know where people want it, if they don’t want to quickly fix this themselves.

[LinusU]

I can confirm that the normal import doesn’t work when using moduleResolution node16 or nodenext. We are currently using the following workaround:

import AjvModule from 'ajv'

// FIXME: https://github.com/ajv-validator/ajv/issues/2047
const Ajv = AjvModule.default

[kalvenschraut]

 import { default as Ajv } from 'ajv'

The above was needed whenever your project was targeting ESM output from typescript. i.e. moduleResolution = NodeNext/Node16+ and module = NodeNext/Node16+.

With typescript 4.8.3 the above actually stopped working and started producing a different type error for me. I stumbled across this comment on a typescript issue. It seems typescript is pointing blame on the libraries being incorrectly typed for whatever reason.

To fix my error I had to switch back to

import Ajv from 'ajv'

and then when I go and try to use the Ajv class it is actually something like

 const ajv = new Ajv.default()