prefer-catch.md

Prefer catch to then(a, b)/then(null, b) for handling errors (promise/prefer-catch)

🔧 This rule is automatically fixable by the --fix CLI option.

A then call with two arguments can make it more difficult to recognize that a catch error handler is present and can be less clear as to the order in which errors will be handled.

Rule Details

The second argument of a then call may be thought to handle any errors in the first argument, but it will only handle errors earlier in the Promise chain.

Examples of incorrect code for this rule:

prom.then(fn1).then(fn2)
prom.catch(handleErr).then(handle)

Examples of incorrect code for this rule:

hey.then(fn1, fn2)
hey.then(null, fn2)