Seneca: Cannot assign to read only property 'enabled' of object '#<Object>'

[ikobiashvili]

When I pass object to use() function as module options I get following error. But this happens only if the object is loaded by config. If I clone the configuration object or hardcode it, then it works fine.

Here are details:
node.js: 6.11.4, 8.9.3, 8.11.2
Seneca: 3.5.0

My conf json:

{
  "analytics":{
    "enabled": true,
    "type":"elasticsearch",
    "url":"abc"
  }
}

This was working fine previously but now produces the error:

var cfg_analytics = config.get('analytics');
seneca.use('../services/gza/event-logger.service',  cfg_analytics);

This works fine:

seneca.use('../services/gza/event-logger.service',  {url:'abc', enabled:true});

This is the error message:

=== SENECA FATAL ERROR ===
MESSAGE:  ::: seneca: Cannot assign to read only property 'enabled' of object '#<Object>'
CODE:     ::: plugin_undefined
INSTANCE  :::  Seneca/7767rwgjflva/1526638227646/23360/3.5.0/-
DETAILS   ::: {}
STACK     :::  TypeError: Cannot assign to read only property 'enabled' of object '#<Object>'
               at build_plugindesc (D:\work\projects\gveli-server\node_modules\use-plugin\use.js:150:31)
               at Object.use (D:\work\projects\gveli-server\node_modules\use-plugin\use.js:68:22)
               at Seneca.api_use [as use] (D:\work\projects\gveli-server\node_modules\seneca\seneca.js:838:29)
               at Object.<anonymous> (D:\work\projects\gveli-server\test\services\gveli-hub\users.service.test.js:14:8)
               at Module._compile (module.js:570:32)
               at Object.Module._extensions..js (module.js:579:10)
               at Module.load (module.js:487:32)
               at tryModuleLoad (module.js:446:12)
               at Function.Module._load (module.js:438:3)
               at Module.require (module.js:497:17)
WHEN      :::  2018-05-18T10:10:27.674Z
LOG       :::  {kind:null,plugin:seneca,tag:3.5.0,id:7767rwgjflva/1526638227646/23360/3.5.0/-,code:plugin_undefined,notice:sen

event-logger.service.js is normal Seneca plugin. It does not affect the error.

module.exports = function ( options ) {
  const seneca = this;
  const analytics_enabled = options.enabled === true;
  const analytics_url = options.url;
  if (analytics_enabled){
    seneca.log.info(`Using analytics at ${analytics_url}`);
  }

  seneca.add({role:'logger', event:'sync'}, (msg, reply) => {
.....

The is the line from use.js of use-plugin where the error happens:

  // Options as an argument to the _use_ function override options
  // in the plugin description object.
  plugindesc.options = Object.assign(plugindesc.options || {}, options || {})

This merging is not directly Seneca code, but to me it looks like Seneca is breaking promise to accept options for plugins. And it was working previously fine.

[rjrodger]

config must be freezing or sealing the options object - a bug for use-plugin

[rjrodger]

rjrodger/use-plugin#7

[rjrodger]

This will be fixed in next release, fixed in rjrodger/use-plugin#7