Extend debug mode to help find subtle errors during development

[Brimstedt]

What problem does this feature solve?

To help developers not get stuck on hard to catch or non apparent bugs, it would be neat if debug mode could check:

• Do we have data properties with same name as a method (to avoid confusing "xxx is not a method)
• Did an object loose reactivity on some property (i.e. did a non getter/setter property on any of the managed objects appear)

Probably there are other helpers to be added as well.

What does the proposed API look like?

There is already an API to turn on debug mode.

Vue.config.debug = true

[yyx990803]

All warnings are on by default in development mode.

There's no way to detect a newly added non-reactive property in ES5.

[Brimstedt]

Thanks for reviewing my feature request!

To bad about the reactivity detection.

What about warning when there is shadowing? I.e. properties, getters or methods with the same names?