promise/prefer-catch Style
What it does
Prefer catch to then(a, b) and then(null, b). This rule disallows the passing of an argument into the second parameter of then calls for handling promise errors.
Why is this bad?
A then call with two arguments can make it more difficult to recognize that a catch error handler is present. Another issue with using the second argument in then calls is that the ordering of promise error handling is less obvious.
For example on first glance it may appear that prom.then(fn1, fn2) is equivalent to prom.then(fn1).catch(fn2). However they aren't equivalent. In fact prom.catch(fn2).then(fn1) is the equivalent. This kind of confusion is a good reason for preferring explicit catch calls over passing an argument to the second parameter of then calls.
Examples
Examples of incorrect code for this rule:
js
prom.then(fn1, fn2);
prom.then(null, fn2);Examples of correct code for this rule:
js
prom.catch(fn2).then(fn1);
prom.catch(fn2);How to use
To enable this rule in the CLI or using the config file, you can use:
bash
oxlint --deny promise/prefer-catch --promise-pluginjson
{
"plugins": ["promise"],
"rules": {
"promise/prefer-catch": "error"
}
}