no-catch-shadow

In Internet Explorer 8 and earlier, a catch clause's parameter leaks into the surrounding scope. If a variable there has the same name, the caught error overwrites it.

The rule reports a catch parameter that has the same name as a variable, function, class or global that's visible at the try statement.

ESLint has deprecated this rule. Use no-shadow instead.

Examples

Reported:

const error = loadLastError();

try {
  save();
} catch (error) {
  console.log(error);
}

Not reported:

const error = loadLastError();

try {
  save();
} catch (saveError) {
  console.log(saveError);
}

When not to use it

Every current browser and runtime keeps the parameter inside the catch clause, so this rule only matters for Internet Explorer 8. It's deprecated. To stop names from hiding each other, use no-shadow.