can.route.attr({}, true) throws an error

[phillipskevin]

Passing an object as the first argument to can.route.attr and anything as the second argument throws an error:

can.route.attr({
  page: 'foo'
}, true);

error TypeError: Cannot define property _instanceDefinitions, object is not extensible
    at Function.defineProperty (<anonymous>)
    at Object.defineExpando (https://unpkg.com/[email protected]/dist/global/can.all.js:14845:24)
    at DefineMap.setKeyValue (https://unpkg.com/[email protected]/dist/global/can.all.js:14939:37)
    at Object.setKeyValue (https://unpkg.com/[email protected]/dist/global/can.all.js:1042:36)
    at DefineMap.attrHelper (https://unpkg.com/[email protected]/dist/global/can.all.js:15725:28)
    at Function.canRoute.attr (https://unpkg.com/[email protected]/dist/global/can.all.js:16107:27)

Here is an example: http://jsbin.com/dipiwikida/1/edit?js,console.

I think this is happening because people were previously using can-map and wanted to set the removeOthers flag and have now switched their appViewModel to DefineMap.

[phillipskevin]

A workaround is to use can.route.data.set(..., true) if you are using a DefineMap to back can-route.

[green3g]

I was running into this when I was binding to a route that was using a defineMap.extend. I fixed it by using {seal:false} on the extended define map.

[phillipskevin]

Related to canjs/can-define#245.