prefer-spread.md

Prefer the spread operator over Array.from(…), Array#concat(…) and Array#slice()

Enforces the use of the spread operator (...) over

• Array.from(…)

  Convert Iterable to Array.

  This rule adds on to the built-in prefer-spread rule, which only flags uses of .apply(). Does not enforce for TypedArray.from().

• Array#concat(…)

  Concat an Array with one or more Array's or Array elements.

• Array#slice()

  Shallow copy an Array.

  Variables named arrayBuffer, blob, buffer, file, and this are ignored.

This rule is partly fixable.

Fail

Array.from(set).map(element => foo(element));

const array = array1.concat(array2);

const copy = array.slice();

Pass

[...set].map(element => foo(element));

const array = [...array1, ...array2];

const tail = array.slice(1);

const copy = [...array];