eslint/operator-assignment Style

⚠️🛠️️ A dangerous auto-fix is available for this rule.

What it does

This rule requires or disallows assignment operator shorthand where possible. It encourages the use of shorthand assignment operators like +=, -=, *=, /=, etc. to make the code more concise and readable.

Why is this bad?

JavaScript provides shorthand operators that combine variable assignment and simple mathematical operations. Failing to use these shorthand operators can lead to unnecessarily verbose code and can be seen as a missed opportunity for clarity and simplicity.

Examples

Examples of incorrect code for this rule with the default always option:

x = x + y;
x = y * x;
x[0] = x[0] / y;
x.y = x.y << z;

Examples of correct code for this rule with the default always option:

x = y;
x += y;
x = y * z;
x = (x * y) * z;
x[0] /= y;
x[foo()] = x[foo()] % 2;
x = y + x; // `+` is not always commutative (e.g. x = "abc")

Examples of incorrect code for this rule with the never option:

x *= y;
x ^= (y + z) / foo();

Examples of correct code for this rule with the never option:

x = x + y;
x.y = x.y / a.b;

Options

This rule has a single string option:

{ type: string, default: "always" }

• always requires assignment operator shorthand where possible
• never disallows assignment operator shorthand

Example:

"eslint/max-nested-callbacks": ["error", "always"]

"eslint/max-nested-callbacks": ["error", "never"]

How to use

To enable this rule in the CLI or using the config file, you can use:

CLI

oxlint --deny operator-assignment

Config (.oxlintrc.json)

{
  "rules": {
    "operator-assignment": "error"
  }
}

References

• Rule Source