Chimpy crashes upon app server restart with --ddp flag

[reinisriekstins]

The problem

I was following the instructions at https://guide.meteor.com/v1.3/testing.html#acceptance-testing to setup an acceptance testing environment with Chimpy, and upon running the command chimpy --ddp=http://localhost:3000 --mocha --watch --path=tests, everything runs correctly and the tests are executed , however upon making any changes to any client or server file in the Meteor app running on localhost:3000, when the server restart finishes, the chimpy process crashes throwing the following stack trace:

TypeError: Cannot read property 'web.browser.legacy' of undefined
    at Object.observer.changed (/path/to/project/node_modules/chimpy/dist/lib/ddp-watcher.js:114:58)
    at /path/to/project/node_modules/xolvio-ddp/lib/ddp-client.js:257:20
    at Function._.each._.forEach (/path/to/project/node_modules/ddp-underscore-patched/underscore.js:112:20)
    at DDPClient._message (/path/to/project/node_modules/xolvio-ddp/lib/ddp-client.js:256:11)
    at Client.<anonymous> (/path/to/project/node_modules/xolvio-ddp/lib/ddp-client.js:97:10)
    at Client.emit (events.js:182:13)
    at Client.EventEmitter.emit (domain.js:442:20)
    at Client.dispatchEvent (/path/to/project/node_modules/faye-websocket/lib/faye/websocket/api/event_target.js:24:10)
    at Client._receiveMessage (/path/to/project/node_modules/faye-websocket/lib/faye/websocket/api.js:134:10)
    at Client.<anonymous> (/path/to/project/node_modules/faye-websocket/lib/faye/websocket/api.js:34:49)
    at Client.emit (events.js:187:15)
    at Client.EventEmitter.emit (domain.js:442:20)
    at Client.<anonymous> (/path/to/project/node_modules/websocket-driver/lib/websocket/driver/hybi.js:460:14)
    at pipe (/path/to/project/node_modules/websocket-extensions/lib/pipeline/index.js:37:40)
    at Pipeline._loop (/path/to/project/node_modules/websocket-extensions/lib/pipeline/index.js:44:3)
    at Pipeline.processIncomingMessage (/path/to/project/node_modules/websocket-extensions/lib/pipeline/index.js:13:8)

This doesn't happen, when I run chimpy without the -ddp flag.

Also tried both running the Meteor app normally the meteor run and running with the test command and acceptance-test-driver: meteor test --full-app --driver-package tmeasday:acceptance-test-driver. Chimpy crashes in either case.

Package versions used

Meteor: 1.8.1
NodeJS bundled with Meteor: 8.11.4
Chimpy: 1.2.0
NodeJS on my machine: 10.10.0
Using MacOS High Sierra 10.13.6

[jirikrepl]

I have the same problem

[jirikrepl]

For anyone still using chimpy, I found a temporary workaround, it will disable test reloads upon code change, but at least it will not crash.
You can still trigger chimp re-run, if you change and save the test.

1. from your error message find ddp-watcher.file
2. Comment lines around self._triggerRerun();