message: Fix undefined problem.
diff: @@ -671,11 +671,12 @@ function pushTokens(block, str, styleName) {
  export function makeFont(style) {
  // FIXME in node-canvas fontWeight is before fontStyle
  // Use `fontSize` `fontFamily` to check whether font properties are defined.
  - return trim((style.fontSize || style.fontFamily) && [
  + var font = (style.fontSize || style.fontFamily) && [
  style.fontStyle,
  style.fontWeight,
  (style.fontSize || 12) + 'px',
  // If font properties are defined, `fontFamily` should not be ignored.
  style.fontFamily || 'sans-serif'
  - ].join(' ')) || style.textFont || style.font;
  + ].join(' ');
  + return font && trim(font) || style.textFont || style.font;
  }
  