Allow overwriting computed values if configured

[jillesme]

We ran into a problem where we couldn't overwrite computed properties in tests. Some of our computed properties are very complicated and it would be easier to just overwrite them in tests rather than overwrite the depending properties.

This fixes #1888 and #1867)

PR FOR MOBX 5

• Added unit tests
• Updated changelog Adds computedConfigurable to changelog #2013
• Updated docs Update docs for #2011 #2012
• Added typescript typings
• Verified that there is no significant performance drop (npm run perf)

[coveralls]

Coverage increased (+0.009%) to 93.955% when pulling 2fd4540 on jillesme:mobx4-master-computed-configurable into a9061f4 on mobxjs:mobx4-master.

[danielkcz]

Please add a warning to docs it shouldn't be abused for regular code, as a test tool it certainly could be useful. Although, I would say that a test that also checks if computed is working properly is more robust than some hacked value.

You should also update changelog, otherwise LGTM.

[jillesme]

@FredyC thank you for the quick response. I've updated the package.json and will create a separate PR on the gh-pages branch to update the docs.

[danielkcz]

I wonder, you have linked #1888 which is clearly about MobX 5 and yet you are doing this change in V4 only? Can you please also make another PR with merge to master? Normally it should be the other way around.

Besides, your docs PR is updating V5 docs, so it should definitely exist in that version :)

[jillesme]

You're right @FredyC - updating all related PRs.

[jillesme]

Last 4 PRs are mine... @FredyC - Is there anything else that needs to be done on my side?