fix: support jest test

[pebo]

avoid parallel import() as this may trigger esm import bugs which blocks jest tests

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[ISSUE TYPE]

#342

Description

See:

• While running oas-tools with jest for unit test cases it throws error: 'request for ./middleware/index.js is not yet fulfilled' #342
• VM ESM with dynamic imports resolves promises before linking is complete nodejs/node#33216
• [Bug]: error TS1343: The 'import.meta' meta-property is only allowed when the '--module' option is 'es2020', 'es2022', 'esnext', 'system', 'node16', or 'nodenext'. kulshekhar/ts-jest#3888
• [ESM] Jest crashes with request for ... is not yet fulfilled linking error jestjs/jest#11434

Implementation details

Perform lay loading of ./index_old.js (oasOld). This avoid the issue with parallel imports.

To verify with jest:

# install jest
npm install -D jest

# add a file jest smoke test in the file: /tests/jest.test.js
import express from 'express';
import oasTools from '@oas-tools/core';
import fs from 'fs';

test("jest test", async () => {
    const app = express();
    const defaults = JSON.parse(fs.readFileSync('tests/testServer/.oastoolsrc'));

    await oasTools.initialize(app, defaults);
});

# add a jest script to package.json
"jest-test": "NODE_OPTIONS=--experimental-vm-modules jest --env=node /tests/jest.test.js",

# run test
npm run jest-test

[coveralls]

Pull Request Test Coverage Report for Build 4301579220

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 91.937%

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Totals
Change from base Build 4287066458:	0.0%
Covered Lines:	889
Relevant Lines:	943

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💛 - Coveralls

[alesancor1]

Hey @pebo, could you take a look at #363 and see if that solves the issue with jest?

However, as I mention there, TS support is planned so I will be working on that line, which means the entrypoint.js and the index_old.js will be probably deleted

[pebo]

Hey @pebo, could you take a look at #363 and see if that solves the issue with jest?

I think that issue was about running jest with esm modules which works fine in general but there's a bug triggered when performing import() function calls in parallel where the same sub-module is loaded twice.

However, as I mention there, TS support is planned so I will be working on that line, which means the entrypoint.js and the index_old.js will be probably deleted

TS support sounds nice but would it make sense to release a 3.0.4 version before that with the current fixes on the develop branch and possible this PR (to solve the jest issue with parallel imports)?

[alesancor1]

I see your point, but the CI/CD will bump the version directly to v3.1.0 due to some feats that have been merged recently. However, I may wait and leave TS for 3.2.0 so I can have more time for it, so yes, if I end up doing that I will merge this.