prefer-destructuring

Require destructuring from arrays and/or objects.

🔧

Some problems reported by this rule are automatically fixable by the --fix ESLint command line option.

💭

This rule requires type information to run.

Examples

This rule extends the base eslint/prefer-destructuring rule. It adds support for TypeScript's type annotations in variable declarations.

`eslint/prefer-destructuring`

const x: string = obj.x; // This is incorrect and the auto fixer provides following untyped fix.
// const { x } = obj;

Open in Playground

`@typescript-eslint/prefer-destructuring`

const x: string = obj.x; // This is correct by default. You can also forbid this by an option.

Open in Playground

And it infers binding patterns more accurately thanks to the type checker.

❌ Incorrect

const x = ['a'];
const y = x[0];

Open in Playground

✅ Correct

const x = { 0: 'a' };
const y = x[0];

Open in Playground

It is correct when enforceForRenamedProperties is not true. Valid destructuring syntax is renamed style like { 0: y } = x rather than [y] = x because x is not iterable.

How to Use

.eslintrc.cjs

module.exports = {
  "rules": {
    // Note: you must disable the base rule as it can report incorrect errors
    "prefer-destructuring": "off",
    "@typescript-eslint/prefer-destructuring": "error"
  }
};

Try this rule in the playground ↗

Options

See eslint/prefer-destructuring options.

This rule adds the following options:

type Options = [
  BasePreferDestructuringOptions[0],
  BasePreferDestructuringOptions[1] & {
    enforceForDeclarationWithTypeAnnotation?: boolean;
  },
];

const defaultOptions: Options = [
  basePreferDestructuringDefaultOptions[0],
  {
    ...basePreferDestructuringDefaultOptions[1],
    enforceForDeclarationWithTypeAnnotation: false,
  },
];

enforceForDeclarationWithTypeAnnotation

When set to true, type annotated variable declarations are enforced to use destructuring assignment.

Examples with { enforceForDeclarationWithTypeAnnotation: true }:

❌ Incorrect

const x: string = obj.x;

Open in Playground

✅ Correct

const { x }: { x: string } = obj;

Open in Playground

When Not To Use It

Type checked lint rules are more powerful than traditional lint rules, but also require configuring type checked linting. See Troubleshooting > Linting with Type Information > Performance if you experience performance degredations after enabling type checked rules.

Resources

• Rule source
• Test source

^{Taken with ❤️ from ESLint core.}