sindresorhus/eslint-plugin-unicorn
Rule proposal: Enforce `.toArray()` at the end of `Iterator` methods chain
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#2,767 opened on Sep 25, 2025
help wantednew rule
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Description
Description
Note that it's a good idea to call
toArray()as a last step of your processing. For example,fibonacci().take(10).toArray().filter(...)is less efficient, because iterator helpers are lazy and avoids creating a temporary array.
From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Iterator/toArray
Examples
// ❌
foo.toArray().filter(...)
// ^^^^^^ Array#filter()
// ✅
foo.filter(...).toArray()
// ^^^^^^ Iterator#filter()
Proposed rule name
not sure
Additional Info
No response