nodejs/node · error · FilterArgumentError

method must be common, ceil or floor

Error message

method must be common, ceil or floor

What it means

The round filter rounds a number to a given precision using one of three strategies: 'common' (Python's round), 'ceil', or 'floor' (via math.ceil/math.floor). Any other method name is invalid because there is no corresponding rounding function to dispatch to.

Source

Thrown at tools/inspector_protocol/jinja2/filters.py:795

    If you don't specify a method ``'common'`` is used.

    .. sourcecode:: jinja

        {{ 42.55|round }}
            -> 43.0
        {{ 42.55|round(1, 'floor') }}
            -> 42.5

    Note that even if rounded to 0 precision, a float is returned.  If
    you need a real integer, pipe it through `int`:

    .. sourcecode:: jinja

        {{ 42.55|round|int }}
            -> 43
    """
    if not method in ('common', 'ceil', 'floor'):
        raise FilterArgumentError('method must be common, ceil or floor')
    if method == 'common':
        return round(value, precision)
    func = getattr(math, method)
    return func(value * (10 ** precision)) / (10 ** precision)


# Use a regular tuple repr here.  This is what we did in the past and we
# really want to hide this custom type as much as possible.  In particular
# we do not want to accidentally expose an auto generated repr in case
# people start to print this out in comments or something similar for
# debugging.
_GroupTuple = namedtuple('_GroupTuple', ['grouper', 'list'])
_GroupTuple.__repr__ = tuple.__repr__
_GroupTuple.__str__ = tuple.__str__

@environmentfilter
def do_groupby(environment, value, attribute):
    """Group a sequence of objects by a common attribute.

View on GitHub (pinned to 1b2de5e052)

Solutions

1. Use one of: 'common', 'ceil', or 'floor' (these are the only supported methods).
2. For truncation use {{ value|round(0, 'floor')|int }} or multiply/integer-divide manually.
3. Compute rounding in Python and pass the result to the template if you need a non-supported mode.

Example fix

{# before #}
{{ 4.7|round(0, 'up') }}

{# after #}
{{ 4.7|round(0, 'ceil') }}

import math
ALLOWED = ('common', 'ceil', 'floor')
if method not in ALLOWED:
    raise ValueError('round method must be one of %r' % (ALLOWED,))

def is_round_method(value: str) -> bool:
    return value in ('common', 'ceil', 'floor')

from jinja2.exceptions import FilterArgumentError
try:
    out = env.call_filter('round', value, args=(precision, method))
except FilterArgumentError:
    out = env.call_filter('round', value, args=(precision, 'common'))

When it happens

Trigger: Calling {{ value|round(precision, method) }} with method not in ('common','ceil','floor') — e.g. {{ 4.2|round(1, 'up') }} or {{ x|round(0, 'nearest') }}.

Common situations: Assuming round supports arbitrary rounding modes (banker's, half-up, truncate); passing a locale-translated method name.

Related errors

• You can only sort by either "key" or "value"
• can't handle positional and keyword arguments at the same ti
• Unexpected keyword argument %r
• map requires a filter argument
• Missing parameter for attribute name

AI-assisted analysis of nodejs/node@1b2de5e052 (2026-08-13). Data as JSON: /api/errors/10abdf96c359b9a4. Report an issue: GitHub.