css in js react native styled component reuse example

style.ts

const pickFontWeight = (
  fontWeight: 'bold' | 'light',
  { fontFamilies }: Theme,
) => {
  switch (fontWeight) {
    case 'bold':
      return css`
        font-family: ${fontFamilies.boldFont};
        font-weight: bold;
      `;
    case 'light':
      return css`
        font-family: ${fontFamilies.lightFont};
        font-weight: 300;
      `;
    default:
      return css`
        font-family: ${fontFamilies.lightFont};
        font-weight: normal;
      `;
  }
};