move input checking from macro to add_disjunction

Author: hdavid16

src/disjunction.jl

@@ -1,17 +1,14 @@
-function add_disjunction(m::Model,disj...;reformulation=:BMR,M=missing,eps=1e-6,name=missing)
+function add_disjunction(m::Model,disj...;reformulation,M=missing,eps=1e-6,name=missing)
     @assert m isa Model "A valid JuMP Model must be provided."
     @assert reformulation in [:BMR, :CHR] "Invalid reformulation method passed to keyword argument `:reformulation`. Valid options are :BMR (Big-M Reformulation) and :CHR (Convex-Hull Reormulation)."
-
+    @assert length(disj) > 1 "At least 2 disjuncts must be included."
     #create binary indicator variables for each disjunction
     disj_name = ismissing(name) ? Symbol("disj",gensym()) : name
     @assert isnothing(variable_by_name(m,string(disj_name))) "Name for disjunction binary cannot be the same as an existing variable."
     eval(:(@variable($m, $disj_name[i = 1:length($disj)], Bin)))
     #enforce exclussive OR
     eval(:(@constraint($m,sum($disj_name[i] for i = 1:length($disj)) == 1)))
     #apply reformulation
-    if reformulation == :BMR
-        reformulate(m, disj, disj_name, reformulation, M)
-    elseif reformulation == :CHR
-        reformulate(m, disj, disj_name, reformulation, eps)
-    end
+    param = reformulation == :BMR ? M : eps
+    reformulate(m, disj, disj_name, reformulation, param)
 end

src/macro.jl

@@ -5,9 +5,6 @@ macro disjunction(args...)
     reformulation = filter(i -> i.args[1] == :reformulation, kw_args)
     if !isempty(reformulation)
         reformulation = reformulation[1].args[2]
-        if length(pos_args[2:end]) < 2
-            throw(DomainError(args, "At least 2 constraints expected"))
-        end
     else
         throw(UndefKeywordError(:reformulation))
     end