default-param-last

Enforce default parameters to be last

Putting default parameter at last allows function calls to omit optional tail arguments.

// Correct: optional argument can be omitted
function createUser(id, isAdmin = false) {}
createUser("tabby")

// Incorrect: optional argument can **not** be omitted
function createUser(isAdmin = false, id) {}
createUser(undefined, "tabby")
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Rule Details

This rule enforces default parameters to be the last of parameters.

Examples of incorrect code for this rule:

/* eslint default-param-last: ["error"] */

function f(a = 0, b) {}

function g(a, b = 0, c) {}
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Examples of correct code for this rule:

/* eslint default-param-last: ["error"] */

function f(a, b = 0) {}
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Version

This rule was introduced in ESLint v6.4.0.

Resources

• Rule source
• Tests source