First visit to "Routes" table via "Routes" tab outputs JS error on app with engines.

[GCheung55]

Issue and Steps to Reproduce

• The first visit to "Routes" table, by selecting the "Routes" tab, displays an empty table and outputs a JS error:

This is likely a bug in the inspector itself.
You can report bugs at https://github.com/emberjs/ember-inspector.
Error message: routeHandler.get is not a function
Stack trace: TypeError: routeHandler.get is not a function
    at o.buildSubTree (<anonymous>:4050:39)
    at o.<anonymous> (<anonymous>:3950:22)
    at Re.Ne.get (https://snapdragon-ws.fitbit.com/assets/vendor-617b03c28e2ef60d43021b01ddd6048c.js:3219:20)
    at Me (https://snapdragon-ws.fitbit.com/assets/vendor-617b03c28e2ef60d43021b01ddd6048c.js:3191:89)
    at o.get (https://snapdragon-ws.fitbit.com/assets/vendor-617b03c28e2ef60d43021b01ddd6048c.js:3828:58)
    at o.sendTree (<anonymous>:3956:30)
    at o.getTree (<anonymous>:3922:14)
    at h (https://snapdragon-ws.fitbit.com/assets/vendor-617b03c28e2ef60d43021b01ddd6048c.js:3070:111)
    at o.trigger (https://snapdragon-ws.fitbit.com/assets/vendor-617b03c28e2ef60d43021b01ddd6048c.js:3826:90)
    at <anonymous>:3502:14

Alternate clicks (14) between another tab and "Routes" tab will eventually have the table display data.

May be related to #632 ?

• Reproduction steps:

1. Go to https://www.fitbit.com/settings (You may need to create an account).
2. Open Ember-Inspector
3. Click on "Routes" tab

Your environment

• Ember Version: 3.1
• Browser: Chrome 76.0.3809.100

Screenshots

The page to visit: https://www.fitbit.com/settings

Expected: Table of routes, objects, and URLs are displayed.

Actual: Table is empty and JS error is output to console. Alternate clicks (14) between another tab and "Routes" tab will eventually have the table display data.

[RobbieTheWagner]

Engines are not currently supported

[steventsao]

Mark this as duplicate to https://github.com/emberjs/ember-inspector/issues/632? @rwwagner90

[RobbieTheWagner]

@steventsao yeah, I suppose they are basically the same ask, but this one does have some more context.

[RobbieTheWagner]

This must have been a timing issue. We use engines at work and I am able to access the Routes tab on the first click. Going to close for now, but please let us know if you are still experiencing issues!