no-with.md

Pattern: Use of with statement

Issue: -

Description

The with statement adds all properties of an object to the current scope, making it impossible to determine whether a variable inside the block refers to a property of the object or a variable in an outer scope. This leads to confusing code and potential bugs.

Examples

Example of incorrect code:

with (math) {
  x = cos(angle);
}

with (object) {
  property = 42;
}

with (point) {
  r = Math.sqrt(x * x + y * y);  // Unclear if r is from point
}

Example of correct code:

const x = math.cos(angle);

object.property = 42;

const r = Math.sqrt(
  point.x * point.x + 
  point.y * point.y
);

// Or use destructuring
const { x, y } = point;
const r = Math.sqrt(x * x + y * y);