Can't import all operators in NodeJS

[stefanholzapfel]

Hi!

I'm on
NodeJS version 14,
Mingo version 3.0.2

I bundle the app with Webpack version 5 (also tried with 4, same effect) and run it via nodemon (2.0.4).

I try to import all operators like that (bundle size is no problem for me):

import { OperatorType, useOperators } from 'mingo/core';
import * as pipelineOperators from 'mingo/operators/pipeline';
import * as projectionOperators from 'mingo/operators/projection';
import * as queryOperators from 'mingo/operators/query';
import * as expressionOperators from 'mingo/operators/expression';
import * as accumulatorOperators from 'mingo/operators/accumulator';

useOperators(OperatorType.PIPELINE, pipelineOperators);
useOperators(OperatorType.PROJECTION, projectionOperators);
useOperators(OperatorType.QUERY, queryOperators);
useOperators(OperatorType.EXPRESSION, expressionOperators);
useOperators(OperatorType.ACCUMULATOR, accumulatorOperators);    

Some of the imports work, some (like in this example arithmetic) throw:

(function (exports, require, module, __filename, __dirname) { export * from './arithmetic';
                                                              ^^^^^^
SyntaxError: Unexpected token 'export'
    at new Script (vm.js:99:7)
    at createScript (vm.js:247:10)
    at Object.runInThisContext (vm.js:295:10)
    at wrapSafe (internal/modules/cjs/loader.js:1104:15)
    at Module._compile (internal/modules/cjs/loader.js:1164:27)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1220:10)
    at Module.load (internal/modules/cjs/loader.js:1049:32)
    at Function.Module._load (internal/modules/cjs/loader.js:937:14)
    at Module.require (internal/modules/cjs/loader.js:1089:19)
    at require (internal/modules/cjs/helpers.js:73:18)
[nodemon] app crashed - waiting for file changes before starting...

Other es6 imports work fine in my app. It also seem to have somehting to do with import ordering (which is weird)?

Any ideas?

Thanks!

[j]

Not sure if this is unrelated, but I couldn't get tests to start b/c this 3.x branch of mingo. I would get a memory leak somehow. Reverting back to the older version of mingo fixes my issue.

[stefanholzapfel]

To be more precise, I get errors with:
useOperators(OperatorType.EXPRESSION, expressionOperators);
and
useOperators(OperatorType.ACCUMULATOR, accumulatorOperators);

Other operators can be imported.

[kofrasa]

@stefanholzapfel thanks for reporting the issues. The error seems related to module loading. Starting from 3.0.0 there is a dependency on the esm which allows using the ES6 import syntax, which is the target of the Typescript build.

If you are getting a syntax error, my guess is that esm is not installed in your environment. Assuming you got that working correctly, then something else must be causing the import of expression and accumulator operators to fail.

Can you provide the exception for those cases and how are you bundling your project?

[kofrasa]

Not sure if this is unrelated, but I couldn't get tests to start b/c this 3.x branch of mingo. I would get a memory leak somehow. Reverting back to the older version of mingo fixes my issue.

@j please open a new issue with the details of the memory leak.

[j]

@kofrasa #145 might be related.

[kofrasa]

I am unable to repro the import errors. Below is my example using esm from my terminal.

➜  ~ node -r esm
Welcome to Node.js v14.4.0.
Type ".help" for more information.
> import 'mingo/init/system'
undefined
> import * as pkg from 'mingo/package.json'
undefined
> pkg.version
'3.0.2'
> import { Query } from 'mingo/query'
undefined
> let q = new Query({a: {$gt: 5}})
undefined
> q
Query {
  __criteria: { a: { '$gt': 5 } },
  __config: { idKey: '_id' },
  __compiled: [ [Function (anonymous)] ]
}
> q.test({a:10})
true
> q.test({a:1})
false
>
> import * as expressionOperators from 'mingo/operators/expression'
undefined
> useOperators(OperatorType.EXPRESSION, expressionOperators)
undefined
>

[stefanholzapfel]

Hi Kofrasa!

Yes you are right, I don't have esm installed, and its a build from Typescript via Webpack.

I don't know the different module builders very well, but I don't unterstand why the ES export syntax works with pipeline, projection and query operators and not with accumulators and expressions. I also use other packages with ES syntax...

The exact error for expression operators is:

C:\xxxx\node_modules\mingo\operators\accumulator\index.js:4
export * from './addToSet';
^^^^^^

SyntaxError: Unexpected token 'export'
    at new Script (vm.js:99:7)
    at createScript (vm.js:247:10)
    at Object.runInThisContext (vm.js:295:10)
    at wrapSafe (internal/modules/cjs/loader.js:1104:15)
    at Module._compile (internal/modules/cjs/loader.js:1164:27)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1220:10)
    at Module.load (internal/modules/cjs/loader.js:1049:32)
    at Function.Module._load (internal/modules/cjs/loader.js:937:14)
    at Module.require (internal/modules/cjs/loader.js:1089:19)
    at require (internal/modules/cjs/helpers.js:73:18)
[nodemon] app crashed - waiting for file changes before starting...

Thank you!

[kofrasa]

I am unable to repro this but the latest version 3.0.3 removes the reliance on the esm module which is likely the root cause.

Closing this issue. Please reopen if the issue still persists after upgrade.

[stefanholzapfel]

Thanks, fixed with new version.