Prefer .flatMap(…) over .map(…).flat()
💼 This rule is enabled in the ✅ recommended config.
🔧 This rule is automatically fixable by the --fix CLI option.
Array#flatMap performs Array#map and Array#flat in one step.
Fail
js
const foo = bar.map(element => unicorn(element)).flat();js
const foo = bar.map(element => unicorn(element)).flat(1);Pass
js
const foo = bar.flatMap(element => unicorn(element));js
const foo = bar.map(element => unicorn(element)).flat(2);js
const foo = bar.map(element => unicorn(element)).foo().flat();js
const foo = bar.flat().map(element => unicorn(element));