IGNIS

Appearance

Changelog - 2026-08-12 ​

Log Arguments Under %j No Longer Collapse to [Circular] ​

Bug Fix Security Behavior Change

In one line. A %j log argument that carries a transaction, a connector or a request context now prints its real fields instead of the single token [Circular].

The problem it solves ​

%j formats through JSON.stringify, which gives up on the whole argument as soon as one cycle sits anywhere inside it. A payload is mostly plain data, so the loss is total and silent:

typescript
logger.debug('Updating user | Args: %j', { id, data, transaction });
// [UserService] [updateById] START | Executing... | Args: [Circular]

The id and the data were never cyclic. The transaction handle holds a live connector, which references its own session, which references it back - and that one edge took the rest of the line with it.

What changed ​

  • Cycles collapse per branch. Only the offending reference prints "[Circular]"; every sibling field survives.
  • Secret-looking keys are redacted under %j, exactly as they already were under %s. Passwords and tokens in a %j payload previously reached the sink in clear.
  • The walk is depth-capped by APP_ENV_LOGGER_INSPECT_DEPTH (default 5), so a live connector cannot flood one line. Below the cap a value prints "[Object]".
  • An Error under %j keeps its message and stack. JSON.stringify alone rendered it as {}, since both fields are non-enumerable.
  • A Date no longer flattens to {} under %s.

The same line now reads:

text
Args: [{"id":"user-1","data":{"username":"phatnt","password":"[REDACTED]"},"transaction":
{"connector":{"query":{"users":"[Object]"},"session":{"dialect":"[Circular]","client":
"[Object]"}},"isActive":true}}]

Who is affected ​

  • Anyone logging with %j. No action needed. Lines that printed [Circular] now print data, and deep payloads truncate at depth 5 rather than running unbounded.
  • Anyone parsing log lines downstream. A %j field that used to be absent (or the literal [Circular]) can now hold "[Circular]", "[Object]", "[Array]" or "[Binary N bytes]" as a string value.
  • Anyone logging an Error with %j. The line grows: it now carries message, stack and every enumerable own property. %s remains the rule for errors - only %s routes through ErrorPrettier, which projects unmodelled properties away.

Details ​

%o, %O and arguments with no placeholder at all are still handed to util.format untouched, so they are not redacted. Bind anything that may carry a credential to %s or %j.

A payload holding a live handle still prints noise. Keep transactions and request contexts out of the logged arguments:

typescript
// Prefer
logger.debug('Updating user | Args: %j', { id, data });

toJsonSafe is exported for the same projection outside the logger:

typescript
import { toJsonSafe } from '@venizia/ignis-helpers';

const safe = toJsonSafe({ value: payload, depth: 5 });
FilePackage
src/common/redact.tshelpers
src/modules/logger/formatting/deep-splat.tshelpers