Migrating from v1 to v2

Version 2 changes the record shape, the stream API and the way the package is imported. The format-parsing logic is the same: results on identical input match, except for what is listed below.

What changed#

v1	v2	Note
`sverlo.parser(opts)`	`createParser(opts)`	New name, same options plus new ones
`parser.parse(line, cb)`	`parser.parseLine(line)`	Callback removed, the result is returned
`rec.time` (string)	`rec.ts` (`Date`)	A real date object now
`rec.severity` (`'WARN'`)	`rec.level` (`'warn'`)	Lower case, normalised
`rec.message`	`rec.msg`
`rec.data`	`rec.fields`	Object without a prototype
`sverlo.createStream(opts)`	`createTransform(opts)`
`require('sverlo')`	`import { createParser } from 'sverlo'`	ESM only

Behaviour#

An unrecognised line used to call the callback with an error; now it is skipped by default. Get the old behaviour back with onError: 'throw'.
Time without a zone was UTC in v1 and is local process time in v2. If you relied on the old behaviour, set timezone: 'UTC'.
Filters in v1 were predicate functions. In v2 you can write a query as well; functions still work.

Checklist#

Replace require with import or a dynamic import().
Rename record properties using the table above.
Set timezone explicitly.
Replace parse(line, cb) callbacks with parseLine(line).
Check that nothing depends on upper-case levels.
Upgrade Node.js to version 20 or newer.

Both packages side by side#

For a gradual move, install v1 under another name:

bash

npm install sverlo1@npm:sverlo@1

Then import legacy from 'sverlo1' and import { createParser } from 'sverlo' work in one project. The old documentation remains in the v1 archive.