Humanizr/Humanizer · error · ArgumentException

Input words cannot be empty.

Error message

Input words cannot be empty.

What it means

TokenMapWordsToNumberConverter.TryConvert throws this ArgumentException at line 46 for null, empty, or whitespace input. Because it is inside the Try overload, both ToNumber and TryToNumber throw on empty phrases; the invariant-integer fast path runs only after this guard.

Source

Thrown at src/Humanizer/Localisation/WordsToNumber/TokenMapWordsToNumberConverter.cs:46

    {
        if (!TryConvert(words, out var parsedValue, out var unrecognizedWord))
        {
            throw new ArgumentException($"Unrecognized number word: {unrecognizedWord}");
        }

        return parsedValue;
    }

    /// <inheritdoc />
    public override bool TryConvert(string words, out long parsedValue) =>
        TryConvert(words, out parsedValue, out _);

    /// <inheritdoc />
    public override bool TryConvert(string words, out long parsedValue, out string? unrecognizedWord)
    {
        if (string.IsNullOrWhiteSpace(words))
        {
            throw new ArgumentException("Input words cannot be empty.");
        }

        if (rules.AllowInvariantIntegerInput &&
            long.TryParse(words.Trim(), NumberStyles.Integer, CultureInfo.InvariantCulture, out parsedValue))
        {
            unrecognizedWord = null;
            return true;
        }

        var normalizedSource = words.Trim();
        var negative = false;

        foreach (var negativePrefix in rules.NegativePrefixes)
        {
            if (!normalizedSource.StartsWith(negativePrefix, StringComparison.Ordinal))
            {
                continue;
            }

View on GitHub (pinned to ffc2b77c0f)

Solutions

1. Guard with !string.IsNullOrWhiteSpace(words) before any number call.
2. Handle blank as a caller-side condition.
3. Normalize upstream so empty never reaches the converter.

Example fix

// before
"".TryToNumber(out var n, CultureInfo.GetCultureInfo("en"));
// after
if (!string.IsNullOrWhiteSpace(input) && input.TryToNumber(out var n, culture))
    Use(n);

if (string.IsNullOrWhiteSpace(words))
    return Result.Skip();
var ok = words.TryToNumber(out var n, culture);

try { var n = words.ToNumber(culture); }
catch (ArgumentException ex) when (ex.Message == "Input words cannot be empty.")
    { /* blank input */ }

When it happens

Trigger: Passing null, string.Empty, or whitespace to any number method on a token-map locale (including the default English fallback). The IsNullOrWhiteSpace check at line 45 fires first.

Common situations: Blank UI fields, trimmed-to-empty values, unvalidated external input, empty substitution for missing data; hitting this via the English fallback when the requested locale is unsupported and the input was empty.

Related errors

• Input words cannot be empty.
• Input words cannot be empty.
• Input words cannot be empty.
• Input words cannot be empty.
• Unrecognized number word: {unrecognizedWord}

AI-assisted analysis of Humanizr/Humanizer@ffc2b77c0f (2026-08-13). Data as JSON: /api/errors/e7a14dd8e4e85b27. Report an issue: GitHub.