Humanizr/Humanizer · error · InvalidOperationException

'{path}' defines unsupported property '{key}'. Supported pro

Error message

'{path}' defines unsupported property '{key}'. Supported properties: {string.Join(", ", supported)}.

What it means

RejectUnknownKeys (DurationCaseModels.cs:1202-1208) enforces a closed schema: each mapping may only contain keys from an allow-list (a case allows only 'units'; a unit allows 'sameAsNominative', 'unsupported', or phrase keys). Any unrecognised key — including a typo, or mixing sameAsNominative with an extra field — throws and names the offending key plus the supported set.

Source

Thrown at src/Humanizer.SourceGenerators/Common/DurationCaseModels.cs:1206

        static bool ContainsInheritanceMarker(SimpleYamlValue value) =>
            value switch
            {
                SimpleYamlScalar scalar => scalar.Value.Contains("↑↑↑", StringComparison.Ordinal),
                SimpleYamlMapping mapping => mapping.Values.Values.Any(ContainsInheritanceMarker),
                SimpleYamlSequence sequence => sequence.Items.Any(ContainsInheritanceMarker),
                _ => false
            };

        static SimpleYamlMapping ExpectMapping(SimpleYamlValue value, string path) =>
            value as SimpleYamlMapping
            ?? throw new InvalidOperationException($"'{path}' must be a mapping.");

        static void RejectUnknownKeys(SimpleYamlMapping mapping, string path, IReadOnlyCollection<string> supported)
        {
            foreach (var key in mapping.Values.Keys.Where(key => !supported.Contains(key)))
            {
                throw new InvalidOperationException(
                    $"'{path}' defines unsupported property '{key}'. Supported properties: {string.Join(", ", supported)}.");
            }
        }
    }
}

View on GitHub (pinned to ffc2b77c0f)

Solutions

1. Remove the unsupported key named in the message.
2. If the key was meant to carry data, rename it to a supported one for that node (case -> 'units'; unit -> 'sameAsNominative'/'unsupported'/phrase).
3. Ensure mutually-exclusive flags (sameAsNominative vs unsupported vs phrase) appear alone.

Example fix

# before - typo + extra key
second:
  sameAsNominative: true
  pluralForm: 'sekundy'   # unsupported
# after
second:
  sameAsNominative: true

# Closed-schema key check for duration-case nodes
$caseKeys  = @('units')
$unitFlags = @('sameAsNominative','unsupported')
function Test-Unknown($node, $allowed, $path) {
    foreach ($k in $node.Keys) { if ($k -notin $allowed) { throw "'$path' has unsupported key '$k' (allowed: $($allowed -join ', '))" } }
}
Test-Unknown $parsed.durationCases.cases.$case $caseKeys "$locale.cases.$case"
foreach ($u in $parsed.durationCases.cases.$case.units.GetEnumerator()) {
    Test-Unknown $u.Value $unitFlags "$locale.cases.$case.units.$($u.Key)"
}

When it happens

Trigger: A case mapping contains a key other than 'units'; a unit mapping mixes 'sameAsNominative' with another key; a typo like 'suported:' or 'unitsMap:'.

Common situations: Leftover experimental keys; copy-paste merging two blocks; misspelled property names; combining mutually-exclusive flags.

Related errors

• '{path}.units' must explicitly define '{unitName}'.
• '{path}.sameAsNominative' must be true.
• '{path}.unsupported' must be true.
• Case overlay '{path}' must explicitly define singular and nu
• '{path}' must be a mapping.

AI-assisted analysis of Humanizr/Humanizer@ffc2b77c0f (2026-08-13). Data as JSON: /api/errors/2c07db3083b3889e. Report an issue: GitHub.