HMCL-dev/HMCL · error · IllegalArgumentException

The author name cannot be empty

Error message

The author name cannot be empty

What it means

Thrown by the ThemePackAuthor compact constructor when the supplied LocalizedText name is empty (mayBeEmpty() is true). An author record with an empty display name is considered meaningless, so the constructor enforces non-emptiness as an invariant.

Solutions

1. Provide a non-empty author name in the manifest: {"author": {"name": "Alice"}}.
2. In code, ensure the LocalizedText passed to the constructor has at least one non-empty value.
3. Fall back to a placeholder name (e.g. "Unknown") if the source metadata is empty.

Example fix

// before
new ThemePackAuthor(LocalizedText.of(""))
// after
new ThemePackAuthor(LocalizedText.of("Alice"))

boolean nonEmptyName(LocalizedText name) {
    return name != null && !name.mayBeEmpty();
}

try { new ThemePackAuthor(name); } catch (IllegalArgumentException e) { if (e.getMessage().contains("cannot be empty")) name = LocalizedText.of("Unknown"); else throw e; }

When it happens

Trigger: Calling new ThemePackAuthor(LocalizedText.of("")) or constructing via fromJson where the name decodes to an empty string, e.g. {"author": {"name": ""}}.

Common situations: Manifest editors that clear the name field but keep the key, scripts that default missing values to empty strings, or users who blanked the author name in a pack-creation UI.

Understand the failure class

Background: "must not be empty", "cannot be empty" — required-field validation errors across open-source libraries — this error's family across 41 libraries.

Related errors

• Resolved background built-in wallpaper ID is blank
• Cannot export a background directory as a theme-pack asset
• Empty theme condition context value
• Localized text cannot be empty object
• ${messagePrefix}${value}

AI-assisted analysis of HMCL-dev/HMCL@24702dc5a0 (2026-09-10). Data as JSON: /api/errors/6daeec3a4865aa70. Report an issue: GitHub.

Appendix: source

Thrown at HMCL/src/main/java/org/jackhuang/hmcl/theme/ThemePackAuthor.java:122

        LocalizedText name = LocalizedText.fromJson(nameJson);
        if (name == null) {
            throw new JsonParseException("The author name is null");
        }

        try {
            return new ThemePackAuthor(name);
        } catch (IllegalArgumentException e) {
            throw new JsonParseException(e);
        }
    }

    /// Creates theme-pack author metadata.
    ///
    /// @param name the localized author display name
    public ThemePackAuthor {
        if (name.mayBeEmpty()) {
            throw new IllegalArgumentException("The author name cannot be empty");
        }
    }

    /// Returns the author display name in the current locale.
    ///
    /// @return the localized author display name
    public String displayName() {
        return name.getText(I18n.getLocale().getCandidateLocales());
    }

    /// Converts this author to its JSON representation.
    ///
    /// @return the JSON object representing this author
    public JsonObject toJsonObject() {
        JsonObject object = new JsonObject();
        object.add("name", name.toJsonElement());
        return object;
    }

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