How to use bunyan serializers - bunyan

Question

I'm trying to use a custom serializer but it doesn't seem to work for me, my serializer is never called. What am I doing wrong?
I create a logger like this:
const mask = token => {
console.log({token})
return typeof token === 'string' ? token.replace(/[^\.]+$/, 'REDACTED') : token
}
const log = context.log = createLogger({
name: '_placeholder',
level: process.env.LOG_LEVEL || 'info',
serializers: {authorization: mask, bearer: mask, Authorization: mask}
})
and then I log like this:
console.log({properties})
log[!status ? 'error' : status < 500 ? 'info' : 'warn']({error: merge({message, ...properties}, status && {status})})
Output piped to bunyan:
{ properties:
{ reason: 'InvalidToken', authorization: 'Bearer foo.bar.baz' } }
[2018-08-14T14:37:11.775Z] INFO: _placeholder/9920 on XXX:
error: {
"message": "Invalid token",
"reason": "InvalidToken",
"authorization": "Bearer foo.bar.baz",
"status": 401
}
EDIT:
I see it only works on top level properties; is there a way to achieve what I'm trying to do here - mask nested properties aptly named?

Answer 1

Well technically this works, but I'm not sure it's something I want to take live considering performance hit:
const jp = require('jsonpath')
class Sanitized extends Writable {
write(object) {
console.log(JSON.stringify(
['authorization', 'bearer'].reduce((object, property) => {
jp.apply(object, `$..${property}`, token => token.replace(/[^.]+$/, 'REDACTED'))
return object
}, merge({}, object))))
}
}
...
const log = context.log = createLogger({
name: '_placeholder',
level: process.env.LOG_LEVEL || 'info',
streams: [{type: 'raw', stream: new Sanitized()}]
})