maybe-combine-errors
v1.0.0
Published
Combine 0 or more errors into one
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maybe-combine-errors
Combine 0 or more errors into one.
Usage
const combine = require('maybe-combine-errors')
const err1 = new Error('one')
const err2 = new Error('two')
console.log(combine([err1, err2]).message)
console.log(combine([err1, err2]) instanceof Error)
console.log(combine([err1, null]) === err1)
console.log(combine([]) === undefined)
throw combine([err1, err2])
$ node example.js
one; two
true
true
true
example.js:9
throw combine([err1, err2])
^
Error: one
at Object.<anonymous> (example.js:3:14)
at Module._compile (internal/modules/cjs/loader.js:945:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:962:10)
at Module.load (internal/modules/cjs/loader.js:798:32)
at Function.Module._load (internal/modules/cjs/loader.js:711:12)
at Function.Module.runMain (internal/modules/cjs/loader.js:1014:10)
at internal/main/run_main_module.js:17:11
Error: two
at Object.<anonymous> (example.js:4:14)
at Module._compile (internal/modules/cjs/loader.js:945:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:962:10)
at Module.load (internal/modules/cjs/loader.js:798:32)
at Function.Module._load (internal/modules/cjs/loader.js:711:12)
at Function.Module.runMain (internal/modules/cjs/loader.js:1014:10)
at internal/main/run_main_module.js:17:11
API
combine(errors)
The errors
argument must be an array.
Elements that are null
or undefined
are skipped. If the array is empty (after skipping null
and undefined
), undefined
will be returned. If the array contains only 1 error, that error will be returned as-is. Otherwise, a combined error with joined messages and a lazily joined stack. Duplicate messages are skipped.
Respects transient-error
and err.expected
: if all errors have .transient === true
then the combined error will also be transient. Same for .expected
, which is useful for the following pattern:
if (err.expected) {
console.error(err.message)
process.exit(1)
} else {
throw err
}
Alternatives
combine-errors
Same message and stack behavior. Different in that it always returns an error regardless of input length.
aggregate-error
Sets message to a joined stack, which means you can't get a human-friendly message with e.g. console.error(err.message)
. Removes "mostly unhelpful" internal Node.js entries from the stack.
Install
With npm do:
npm install maybe-combine-errors
License
MIT © 2020-present Vincent Weevers