feat(eslint-plugin): [restrict-plus-operands] check +=

[a-tarasyuk]

Fixes #878

[typescript-eslint]

Thanks for the PR, @a-tarasyuk!

typescript-eslint is a 100% community driven project, and we are incredibly grateful that you are contributing to that community.

The core maintainers work on this in their personal time, so please understand that it may not be possible for them to review your work immediately.

Thanks again!

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[codecov]

Codecov Report

Merging #892 into master will increase coverage by 0.02%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #892      +/-   ##
==========================================
+ Coverage   94.23%   94.25%   +0.02%     
==========================================
  Files         126      126              
  Lines        5377     5379       +2     
  Branches     1510     1511       +1     
==========================================
+ Hits         5067     5070       +3     
  Misses        177      177              
+ Partials      133      132       -1

Impacted Files	Coverage Δ
.../eslint-plugin/src/rules/restrict-plus-operands.ts	100% <100%> (+2.77%)	⬆️

[bradzacher]

LGTM - thanks for this

[bradzacher]

Hmm - I hate doing this, but technically this is a breaking feature change, could you please add an option for this check, that is off by default?

We can switch it to be on by default with the next major.

[bradzacher]

lgtm thanks!