ESM export is commonjs about bbi-js

[manzt]

To be discoverable to Node's resolver (and also most bundlers have now implemented), you'd need to use package entrypoints or add "type": "module" to your package.json. FWIW, I think it is more trouble than it's worth to maintain a dual true ESM & commonjs package. There are enough edge cases that it's a massive headache.

I've moved towards any new project just shipping ESM with basically no polyfills/transpiling. Sometimes just TS within JSDoc, so no build step even - package is the source code. But I know that many projects have different communities/concerns and don't have that ability. There's a good guide on the details of ESM here: https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c

[cmdcolin]

nice catch. I think it may take some work to make these true ESM packages...produces some errors when using e.g. module:es2020

yarn run v1.22.18
$ tsc --target es2018 --outDir esm --module es2020
node_modules/@types/babel__core/index.d.ts:12:31 - error TS2792: Cannot find module '@babel/parser'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

12 import { ParserOptions } from '@babel/parser';
                                 ~~~~~~~~~~~~~~~

node_modules/@types/babel__core/index.d.ts:15:20 - error TS2792: Cannot find module '@babel/types'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

15 import * as t from '@babel/types';
                      ~~~~~~~~~~~~~~

node_modules/@types/babel__generator/index.d.ts:10:20 - error TS2792: Cannot find module '@babel/types'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

10 import * as t from '@babel/types';
                      ~~~~~~~~~~~~~~

node_modules/@types/babel__template/index.d.ts:9:31 - error TS2792: Cannot find module '@babel/parser'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

9 import { ParserOptions } from '@babel/parser';
                                ~~~~~~~~~~~~~~~

node_modules/@types/babel__template/index.d.ts:10:48 - error TS2792: Cannot find module '@babel/types'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

10 import { Expression, Program, Statement } from '@babel/types';
                                                  ~~~~~~~~~~~~~~

node_modules/@types/babel__traverse/index.d.ts:13:20 - error TS2792: Cannot find module '@babel/types'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

13 import * as t from '@babel/types';
                      ~~~~~~~~~~~~~~

node_modules/@types/babel__traverse/index.d.ts:63:18 - error TS2411: Property 'blacklist' of type 'any[] | undefined' is not assignable to 'string' index type '(VisitNode<S, any> & VisitNode<S, t.Aliases>) | undefined'.

63 export interface TraverseOptions<S = Node> extends Visitor<S> {
                    ~~~~~~~~~~~~~~~

node_modules/@types/babel__traverse/index.d.ts:63:18 - error TS2411: Property 'denylist' of type 'any[] | undefined' is not assignable to 'string' index type '(VisitNode<S, any> & VisitNode<S, t.Aliases>) | undefined'.

63 export interface TraverseOptions<S = Node> extends Visitor<S> {
                    ~~~~~~~~~~~~~~~

node_modules/@types/babel__traverse/index.d.ts:64:5 - error TS2411: Property 'scope' of type 'Scope | undefined' is not assignable to 'string' index type '(VisitNode<S, any> & VisitNode<S, t.Aliases>) | undefined'.

64     scope?: Scope | undefined;
       ~~~~~

node_modules/@types/babel__traverse/index.d.ts:65:5 - error TS2411: Property 'noScope' of type 'boolean | undefined' is not assignable to 'string' index type '(VisitNode<S, any> & VisitNode<S, t.Aliases>) | undefined'.

65     noScope?: boolean | undefined;
       ~~~~~~~

node_modules/@types/babel__traverse/index.d.ts:248:69 - error TS2536: Type '"type"' cannot be used to index type 'T'.

248     type: T extends null | undefined ? undefined : T extends Node ? T['type'] : string | undefined;
                                                                        ~~~~~~~~~

node_modules/@types/jest/index.d.ts:537:51 - error TS2792: Cannot find module 'jest-diff'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

537             diff(a: any, b: any, options?: import("jest-diff").DiffOptions): string | null;
                                                      ~~~~~~~~~~~

node_modules/@types/jest/index.d.ts:591:44 - error TS2792: Cannot find module 'pretty-format'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

591     type SnapshotSerializerPlugin = import('pretty-format').Plugin;
                                               ~~~~~~~~~~~~~~~

src/bbi.ts:2:58 - error TS2792: Cannot find module 'generic-filehandle'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

2 import { LocalFile, RemoteFile, GenericFilehandle } from 'generic-filehandle'
                                                           ~~~~~~~~~~~~~~~~~~~~

src/bbi.ts:3:38 - error TS2792: Cannot find module 'rxjs'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

3 import { Observable, Observer } from 'rxjs'
                                       ~~~~~~

src/bbi.ts:4:24 - error TS2792: Cannot find module 'rxjs/operators'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

4 import { reduce } from 'rxjs/operators'
                         ~~~~~~~~~~~~~~~~

src/bbi.ts:6:22 - error TS2792: Cannot find module 'quick-lru'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

6 import QuickLRU from 'quick-lru'
                       ~~~~~~~~~~~

src/bbi.ts:376:21 - error TS7006: Parameter 'acc' implicitly has an 'any' type.

376       .pipe(reduce((acc, curr) => acc.concat(curr)))
                        ~~~

src/bbi.ts:376:26 - error TS7006: Parameter 'curr' implicitly has an 'any' type.

376       .pipe(reduce((acc, curr) => acc.concat(curr)))
                             ~~~~

src/bigbed.ts:2:45 - error TS2792: Cannot find module 'rxjs'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

2 import { Observable, Observer, merge } from 'rxjs'
                                              ~~~~~~

src/bigbed.ts:3:29 - error TS2792: Cannot find module 'rxjs/operators'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

3 import { map, reduce } from 'rxjs/operators'
                              ~~~~~~~~~~~~~~~~

src/bigbed.ts:5:22 - error TS2792: Cannot find module 'quick-lru'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

5 import QuickLRU from 'quick-lru'
                       ~~~~~~~~~~~

src/bigbed.ts:225:17 - error TS7006: Parameter 'acc' implicitly has an 'any' type.

225         reduce((acc, curr) => acc.concat(curr)),
                    ~~~

src/bigbed.ts:225:22 - error TS7006: Parameter 'curr' implicitly has an 'any' type.

225         reduce((acc, curr) => acc.concat(curr)),
                         ~~~~

src/bigbed.ts:226:13 - error TS7006: Parameter 'x' implicitly has an 'any' type.

226         map(x => {
                ~

src/blockView.ts:2:26 - error TS2792: Cannot find module 'rxjs'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

2 import { Observer } from 'rxjs'
                           ~~~~~~

src/blockView.ts:5:35 - error TS2792: Cannot find module 'generic-filehandle'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

5 import { GenericFilehandle } from 'generic-filehandle'
                                    ~~~~~~~~~~~~~~~~~~~~

src/blockView.ts:7:22 - error TS2792: Cannot find module 'quick-lru'. Did you mean to set the 'moduleResolution' option to 'node', or to add aliases to the 'paths' option?

7 import QuickLRU from 'quick-lru'
                       ~~~~~~~~~~~

src/blockView.ts:233:15 - error TS2339: Property 'buffer' does not exist on type '{ bytesRead: number; buffer: Buffer; } | undefined'.

233       const { buffer } = await this.cirTreePromise
                  ~~~~~~


Found 29 errors.

[cmdcolin]

Actually just added the moduleResolution:'node' for a possible fix here... #48

would you be able to test it out? does your ESM system require the .js extensions on imports and things like that? this build does not have that

[manzt]

Thanks for having a look!

would you be able to test it out?

should be able to check it out later today or tomorrow

does your ESM system require the .js extensions on imports and things like that? this build does not have that.

It does not, just using via a bundler. Although not technically ESM without the extensions (e.g., cannot run node dist/esm/index.js), the "module" field in the package.json is only recognized by bundlers so this export shouldn't be discoverable from nodes module resolver. (read: maybe ESM not the best naming, but should be totally fine).

[cmdcolin]

the "module" field in the package.json is only recognized by bundlers so this export shouldn't be discoverable from nodes module resolver

gotcha, that's good to know and was basically my intention behind making the module field available...just have a version that has less polyfills/transpilation. would have to dig deeper for the true ESM thing

[cmdcolin]

went ahead and merged, felt like a safe move as we're not going for the "true ESM" type module here :)

[cmdcolin]

let me know if anything else comes up though! thanks for reporting

[manzt]

went ahead and merged, felt like a safe move as we're not going for the "true ESM" type module here :)

Totally agree. Thanks for the quick response/fix! Cheers.