Support kwargs in variable macro

[odow]

Closes #1884

[codecov]

Codecov Report

Merging #2465 (4c0036b) into master (c432f66) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #2465      +/-   ##
==========================================
+ Coverage   92.23%   92.25%   +0.01%     
==========================================
  Files          43       43              
  Lines        4652     4661       +9     
==========================================
+ Hits         4291     4300       +9     
  Misses        361      361              

Impacted Files	Coverage Δ
src/macros.jl	92.30% <100.00%> (+0.15%)	⬆️

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[blegat]

How did the keyword arguments work before this ? Looking at your code, it seems they are all merged into the first arguments and you need to flatten it at the end of the list.

[odow]

How did the keyword arguments work before this?

They didn't. They just resulted in weird error messages:

julia> @variable(model; variable_type = :foo_bar)
ERROR: MethodError: no method matching _valid_model(::Expr; variable_type=:foo_bar)
Closest candidates are:
  _valid_model(::Any, ::Any) at /Users/oscar/.julia/dev/JuMP/src/macros.jl:39 got unsupported keyword argument "variable_type"
  _valid_model(::AbstractModel, ::Any) at /Users/oscar/.julia/dev/JuMP/src/macros.jl:38 got unsupported keyword argument "variable_type"
Stacktrace:
 [1] top-level scope at REPL[10]:1

[blegat]

Ah ok, what doesn't work is when you use a semicolon, I missed that