Node.js · Senior · Question 51 of 75

What is the 'dual package hazard'?

1Two packages with the same name on npm
2A package that depends on itself
✓Correct answer: A package shipped as both CJS and ESM may be loaded twice in one app, creating two copies of its state and failing instanceof checks

Explanation

Solutions: ship ESM only now that require(esm) works, or keep state in one format and wrap it in the other.

Further reading

Node.js API: Packages ↗

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