# es/no-array-prototype-flat

disallow the Array.prototype.{flat,flatMap} method

✅ The following configurations enable this rule: plugin:es/no-new-in-es2019, plugin:es/restrict-to-es3, plugin:es/restrict-to-es5, plugin:es/restrict-to-es2015, plugin:es/restrict-to-es2016, plugin:es/restrict-to-es2017, and plugin:es/restrict-to-es2018

This rule is silent by default because it's hard to know types. You need to configure the aggressive mode or TypeScript in order to enable this rule.

# 💡 Examples

⛔ Examples of incorrect code for this rule:

/*eslint es/no-array-prototype-flat: [error, { aggressive: true }] */
foo.flat(0)
foo.flatMap(e => [e, 2 * e])

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This rule has an option.

rules:
  es/no-array-prototype-flat: [error, { aggressive: false }]

Configure the aggressive mode for only this rule. This is prior to the settings.es.aggressive setting.