Function initProperty

ses.cjs:3722–3738

(obj, name, desc)

// get masked as one overwrites the other. Accordingly, the thrown error
// complains of a "Conflicting definition".
function initProperty(obj, name, desc) {
  if( objectHasOwnProperty(obj, name)) {
    const preDesc=  getOwnPropertyDescriptor(obj, name);
    if(
      !preDesc||
      !is(preDesc.value, desc.value)||
      preDesc.get!==  desc.get||
      preDesc.set!==  desc.set||
      preDesc.writable!==  desc.writable||
      preDesc.enumerable!==  desc.enumerable||
      preDesc.configurable!==  desc.configurable)
      {
      throw TypeError( `Conflicting definitions of ${name}`);
     }
   }
  defineProperty(obj, name, desc);
 }

// Like defineProperties, but throws if it would modify an existing property.
// This ensures that the intrinsics added to the intrinsics collector object