noFlatMapIdentity
Diagnostic Category: lint/correctness/noFlatMapIdentity
Since: v1.7.0
Sources:
- Same as:
flat_map_identity
Disallow to use unnecessary callback on flatMap.
To achieve the same result (flattening an array) more concisely and efficiently, you should use flat instead.
Examples
Section titled ExamplesInvalid
Section titled Invalidarray.flatMap((arr) => arr);code-block.js:1:1 lint/correctness/noFlatMapIdentity FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
✖ Avoid unnecessary callback in flatMap call.
> 1 │ array.flatMap((arr) => arr);
│ ^^^^^^^^^^^^^^^^^^^^^^^^^^^
2 │
ℹ You can just use flat to flatten the array.
ℹ Safe fix: Replace unnecessary flatMap call to flat instead.
1 │ - array.flatMap((arr)·=>·arr);
1 │ + array.flat();
2 2 │
array.flatMap((arr) => {return arr});code-block.js:1:1 lint/correctness/noFlatMapIdentity FIXABLE ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
✖ Avoid unnecessary callback in flatMap call.
> 1 │ array.flatMap((arr) => {return arr});
│ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2 │
ℹ You can just use flat to flatten the array.
ℹ Safe fix: Replace unnecessary flatMap call to flat instead.
1 │ - array.flatMap((arr)·=>·{return·arr});
1 │ + array.flat();
2 2 │
Valid
Section titled Validarray.flatMap((arr) => arr * 2);