Function createTheme

packages/mui-material/src/styles/createTheme.ts:61–146

(
  options: ThemeOptions = {} as any, // cast type to skip module augmentation test
  ...args: object[]
)

 * @returns A complete, ready-to-use theme object.
 */
export default function createTheme(
  options: ThemeOptions = {} as any, // cast type to skip module augmentation test
  ...args: object[]
): Theme {
  const {
    palette,
    cssVariables = false,
    colorSchemes: initialColorSchemes = !palette ? { light: true } : undefined,
    defaultColorScheme: initialDefaultColorScheme = palette?.mode,
    ...other
  } = options;
  const defaultColorSchemeInput = (initialDefaultColorScheme as DefaultColorScheme) || 'light';
  const defaultScheme = initialColorSchemes?.[defaultColorSchemeInput];
  const colorSchemesInput = {
    ...initialColorSchemes,
    ...(palette
      ? {
          [defaultColorSchemeInput]: {
            ...(typeof defaultScheme !== 'boolean' && defaultScheme),
            palette,
          },
        }
      : undefined),
  };

  if (cssVariables === false) {
    if (!('colorSchemes' in options)) {
      // Behaves exactly as v5
      return createThemeNoVars(options as ThemeNoVarsOptions, ...args);
    }

    let paletteOptions = palette;
    if (!('palette' in options)) {
      if (colorSchemesInput[defaultColorSchemeInput]) {
        if (colorSchemesInput[defaultColorSchemeInput] !== true) {
          paletteOptions = colorSchemesInput[defaultColorSchemeInput].palette;
        } else if (defaultColorSchemeInput === 'dark') {
          // @ts-ignore to prevent the module augmentation test from failing
          paletteOptions = { mode: 'dark' };
        }
      }
    }

    const theme = createThemeNoVars(
      { ...options, palette: paletteOptions } as ThemeNoVarsOptions,
      ...args,
    ) as unknown as Theme & {
      defaultColorScheme?: 'light' | 'dark' | undefined;
      colorSchemes?: Partial<Record<string, any>> | undefined;
    };

    theme.defaultColorScheme = defaultColorSchemeInput;
    theme.colorSchemes = colorSchemesInput as Record<string, ColorSystem>;

    if (theme.palette.mode === 'light') {
      theme.colorSchemes.light = {
        ...(colorSchemesInput.light !== true && colorSchemesInput.light),
        palette: theme.palette,