fix MTK tests due to one(x) change in StaticArrays

Author: ChrisRackauckas

src/function_registration.jl

@@ -59,3 +59,4 @@ Base.:^(x::Expression,y::T) where T <: Rational = Operation(Base.:^, Expression[
 @register Base.conj(x)
 @register Base.getindex(x,i)
 Base.getindex(x::Operation,i::Int64) = Operation(getindex,[x,i])
+Base.one(::Operation) = 1

src/simplify.jl

@@ -14,7 +14,7 @@ end
 simplify_constants(x, shorten_tree) = x
 simplify_constants(x) = simplify_constants(x, true)
 
-
+Base.isone(x::Operation) = x.op == one || x.op == Constant && isone(x.args)
 const AC_OPERATORS = (*, +)
 
 function _simplify_constants(O::Operation, shorten_tree)

test/direct.jl

@@ -26,6 +26,7 @@ for i in 1:3
     ∇ = ModelingToolkit.gradient(eqs[i],[x,y,z])
     @test isequal(∂[i,:],∇)
 end
+                   
 @test all(isequal.(ModelingToolkit.gradient(eqs[1],[x,y,z]),[σ * -1,σ,0]))
 @test all(isequal.(ModelingToolkit.hessian(eqs[1],[x,y,z]),0))
 

test/runtests.jl

@@ -9,4 +9,4 @@ using ModelingToolkit, Test
 @testset "Constraints Test" begin include("constraints.jl") end
 @testset "PDE Construction Test" begin include("pde.jl") end
 @testset "Distributed Test" begin include("distributed.jl") end
-#@testset "Latexify recipes Test" begin include("latexify.jl") end
+@testset "Latexify recipes Test" begin include("latexify.jl") end