Function resolveTheme

src/config/OptionResolver.ts:455–491

(themeInput: unknown)

};

const resolveTheme = (themeInput: unknown): ThemeConfig => {
  const base = getTheme('dark');

  if (typeof themeInput === 'string') {
    const name = themeInput.trim().toLowerCase();
    return name === 'light' ? getTheme('light') : getTheme('dark');
  }

  if (themeInput === null || typeof themeInput !== 'object' || Array.isArray(themeInput)) {
    return base;
  }

  const input = themeInput as Partial<Record<keyof ThemeConfig, unknown>>;
  const takeString = (key: keyof ThemeConfig): string | undefined => {
    const v = input[key];
    if (typeof v !== 'string') return undefined;
    const trimmed = v.trim();
    return trimmed.length > 0 ? trimmed : undefined;
  };

  const fontSizeRaw = input.fontSize;
  const fontSize =
    typeof fontSizeRaw === 'number' && Number.isFinite(fontSizeRaw) ? fontSizeRaw : undefined;

  const colorPaletteCandidate = sanitizePalette(input.colorPalette);

  return {
    backgroundColor: takeString('backgroundColor') ?? base.backgroundColor,
    textColor: takeString('textColor') ?? base.textColor,
    axisLineColor: takeString('axisLineColor') ?? base.axisLineColor,
    axisTickColor: takeString('axisTickColor') ?? base.axisTickColor,
    gridLineColor: takeString('gridLineColor') ?? base.gridLineColor,
    colorPalette: colorPaletteCandidate.length > 0 ? colorPaletteCandidate : Array.from(base.colorPalette),
    fontFamily: takeString('fontFamily') ?? base.fontFamily,
    fontSize: fontSize ?? base.fontSize,
  };
};

const normalizeOptionalColor = (color: unknown): string | undefined => {
  if (typeof color !== 'string') return undefined;