[LESS Plugin] Exports all visible LESS variables to CSS custom properties in the scope of @plugin call

exportVars.js

let vars;

registerPlugin({
  install(less, pluginManager, functions) {
    functions.add('exportVars', () => {
      return vars;
    });
  },
  
  eval(context) {
    vars = "";
    
    for(const frame of context.frames) {
      for(let variable of Object.values(frame.variables())) {
        variable = variable.eval(context);
        
        const varName = variable.name.substr(1)
                                     .split(/([A-Z][a-z]+)/)
                                     .filter(x => x).map(el => el.toLowerCase())
                                     .join("-");
        
        const value = variable.value.toCSS(context);
        if(value) vars += `--${varName}: ${value};\n`;
      }
    }
  },
});