Silencing errors on failures for npm run-script

Question

When you run npm test and it fails, you get the test outputs + a single error message, like so:

npm ERR! Test failed.  See above for more details.
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Answer 1

You can silence the errors by redirecting the stderr to /dev/null. For example:

{
 "test": "karma start" (package.json)
}

running:

$ npm run test 2> /dev/null

will now send all npm errors to /dev/null but normal input will still be visible in the console.

Because the error is thrown by npm, after karma exiting with a non-zero status, doing the following is not enough:

 {
     "test": "karma start 2> /dev/null"
 }

but you can overcome it by creating another task that calls that task with stderr redirection:

 {
     "test": "karma start",
     "test:silent": "npm run test 2> /dev/null" 
 }

this will ensure that the npm error messages are hidden