Function coerceConcrete

site/src/theme/themeMode.ts:38–41

(
	value: string | undefined,
	fallback: ConcreteThemeName,
)

};

const coerceConcrete = (
	value: string | undefined,
	fallback: ConcreteThemeName,
): ConcreteThemeName => (isConcreteThemeName(value) ? value : fallback);

/**
 * Maps every concrete theme to its opposite-scheme counterpart in the