Unable import in TypeScript since v5+

[andy1547]

Using the latest v5.2.0 package (containing JS and TypeScript index.d.ts), I've tried the following:

Importing with ESM default:

import Long from "long";
import Long from "long/umd";
// these statements give the following error:
TS1259: Module '"node_modules\\long\\index"' can only be default-imported using the 'allowSyntheticDefaultImports' flag

Importing everything with import *, I use this syntax to import CommonJs modules that export a single object (without default) e.g. import * as jquery from 'jquery':

import * as Long from "long";
import * as Long from "long/umd";
TS2497: This module can only be referenced with ECMAScript imports/exports by turning on the 'esModuleInterop' flag and referencing its default export.

When I change my TypeScript module output from ESM to AMD (AMD output permits the require syntax), it will compile:

import Long = require("long");
import Long = require("long/umd");

// unfortunately I'm unable to use this syntax with ESM output, which is a blocker for us: 
TS1202: Import assignment cannot be used when targeting ECMAScript modules. Consider using 'import * as ns from "mod"', 'import {a} from "mod"', 'import d from "mod"', or another module format instead.

It's also possible to get this working with v4.0.0 with @types/long v4.0.1 (separate package before types were bundled in v5+) when using the import * as Long from "long" syntax when module output is ESM.

It seems strange to me that the TypeScript declaration exports with = but the JavaScript exports with an ESM default. I suspect the mix/matching of these styles causes the error. The ESM JS/TS should stick to ESM imports/exports and the UMD JS/TS should stick to UMD exports.

[owstron]

I was able to import from version 5.0.1 which had export default Long by using import Long from 'long', I could not import it either via import * as Long from 'long', import { Long } from 'long' or import Long from 'long'. With 5.2.0 I had to use import Long = require('long').
Btw, my TsConfig setting is set to { module: 'ESNext' }

[creatorapp]

Is there any fix coming in for this? Looks like google packages like firebase-admin and firebase-tools depend on this module. With the following tsconfig.json,

  "compilerOptions": {
    "experimentalDecorators": true,
    "esModuleInterop": true,
    "module": "ESNext",
    "target": "esnext",
    "moduleResolution": "nodenext",
    "allowJs": true,
    "strict": false,
    "sourceMap": true,
    "outDir": "dist",
    "rootDir": "./src",
    "emitDecoratorMetadata": true,
    "types": ["reflect-metadata"],
    "lib": ["es6", "dom"]
  },
  "lib": ["es2015"],
  "include": ["src/**/*.ts"]

I continue to get the error:

node_modules/@grpc/proto-loader/build/src/index.d.ts:22:23 - error TS1471: Module 'long' cannot be imported using this construct. The specifier only resolves to an ES module, which cannot be imported with 'require'. Use an ECMAScript import instead.

22 import Long = require('long');

[russellsteadman]

The source of this error is:

long.js/index.d.ts

Line 446 in 3cea40d

export = Long; // compatible with `import Long from "long"`

This is only compatible with synthetic ES modules being exported as CommonJS. For true ES modules this should be:

export default Long;

See the TypeScript documentation which states that separate type definitions can be specified (scroll to the code bubble right after the "The new support works similarly with import conditions." paragraph).

[dcodeIO]

Thanks @russellsteadman for the PR! There should be a new release at 0 UTC. Lmk if there are remaining issues with the fix in place.

[magiclen]

v5.2.2 shows Module not found: Error: Default condition should be last one when webpack is running. But v5.2.1 does not have this error.

I'm using ESM + Webpack + TS.

[dcodeIO]

Reordered in v5.2.3, lmk!

[nhuethmayr]

Any news on this?

[JustDoItSascha]

No updates on this for 3 months?