test: test analysis points

Author: AayushSabharwal

test/analysis_points.jl

@@ -0,0 +1,23 @@
+using ModelingToolkit, ModelingToolkitStandardLibrary
+using Test
+using ModelingToolkit: t_nounits as t, D_nounits as D
+
+@testset "AnalysisPoint is lowered to `connect`" begin
+    @named P = FirstOrder(k = 1, T = 1)
+    @named C = Gain(; k = -1)
+    
+    ap = AnalysisPoint(:plant_input)
+    eqs = [connect(P.output, C.input)
+           connect(C.output, ap, P.input)]
+    sys_ap = ODESystem(eqs, t, systems = [P, C], name = :hej)
+    sys_ap2 = @test_nowarn expand_connections(sys)
+
+    @test all(eq -> !(eq.lhs isa AnalysisPoint), equations(sys_ap2))
+
+    eqs = [connect(P.output, C.input)
+           connect(C.output, P.input)]
+    sys_normal = ODESystem(eqs, t, systems = [P, C], name = :hej)
+    sys_normal2 = @test_nowarn expand_connections(sys)
+
+    @test isequal(sys_ap2, sys_normal2)
+end

test/runtests.jl

@@ -84,6 +84,7 @@ end
             @safetestset "print_tree" include("print_tree.jl")
             @safetestset "Constraints Test" include("constraints.jl")
             @safetestset "IfLifting Test" include("if_lifting.jl")
+            @safetestset "Analysis Points Test" include("analysis_points.jl")
         end
     end