Use `Object.create(null)` to avoid inherit properties like `constructor` #2

sileix · 2021-06-29T22:57:18Z

Objects created from literal syntax will inherit properties from
Object.prototype, which includes constructor.
As a result, lexcon['constructor'] will return a function object
instead of undefined.

This bug was discovered while using en-pos, and can be reproduced by the following code:

const Tag = require("en-pos").Tag;
const tags = new Tag(["constructor"]).initial() .smooth().tags;

During initial(), it calls lexicon.ts where it assumes the return value of lexicon[token] is either undefined or string.

Object created from literal syntax will inherit properties from `Object.prototype`, which includes `constructor`. As a result, `lexcon['constructor']` will return a function object instead of undefined.

Use Object.create(null) to avoid inherit properties like constructor

56ab5af

Object created from literal syntax will inherit properties from `Object.prototype`, which includes `constructor`. As a result, `lexcon['constructor']` will return a function object instead of undefined.

sileix mentioned this pull request Oct 12, 2021

Wikidata refactor stanford-oval/genie-toolkit#813

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Use `Object.create(null)` to avoid inherit properties like `constructor` #2

Use `Object.create(null)` to avoid inherit properties like `constructor` #2

sileix commented Jun 29, 2021

Use Object.create(null) to avoid inherit properties like constructor #2

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Use Object.create(null) to avoid inherit properties like constructor #2

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sileix commented Jun 29, 2021

Use `Object.create(null)` to avoid inherit properties like `constructor` #2

Use `Object.create(null)` to avoid inherit properties like `constructor` #2