added test for symbolic continuous_events (#1728)

Author: hstrey

test/runtests.jl

@@ -5,6 +5,7 @@ using SafeTestsets, Test
 @safetestset "AbstractSystem Test" begin include("abstractsystem.jl") end
 @safetestset "Variable scope tests" begin include("variable_scope.jl") end
 @safetestset "Symbolic parameters test" begin include("symbolic_parameters.jl") end
+@safetestset "Symbolic event test" begin include("symbolic_events.jl") end
 @safetestset "Parsing Test" begin include("variable_parsing.jl") end
 @safetestset "Simplify Test" begin include("simplify.jl") end
 @safetestset "Direct Usage Test" begin include("direct.jl") end
@@ -41,7 +42,6 @@ println("Last test requires gcc available in the path!")
 @testset "Serialization" begin include("serialization.jl") end
 @safetestset "print_tree" begin include("print_tree.jl") end
 @safetestset "error_handling" begin include("error_handling.jl") end
-@safetestset "root_equations" begin include("root_equations.jl") end
 @safetestset "state_selection" begin include("state_selection.jl") end
 @safetestset "Modelingtoolkitize Test" begin include("modelingtoolkitize.jl") end
 @safetestset "OptimizationSystem Test" begin include("optimizationsystem.jl") end

test/root_equations.jl renamed to test/symbolic_events.jl

@@ -555,3 +555,29 @@ let rng = rng
     @named jsys6 = JumpSystem(eqs, t, [A], [k, t1, t2], discrete_events = [cb2‵‵‵, cb1])
     testsol(jsys6, u0, p, tspan; tstops = [1.0, 2.0], rng)
 end
+
+let
+    @variables t
+    D = Differential(t)
+
+    function oscillator_ce(k = 1.0; name)
+        sts = @variables x(t)=1.0 v(t)=0.0 F(t)
+        ps = @parameters k=k Θ=0.5
+        eqs = [D(x) ~ v, D(v) ~ -k * x + F]
+        ev = [x ~ Θ] => [x ~ 1.0, v ~ 0.0]
+        ODESystem(eqs, t, sts, ps, continuous_events = [ev]; name)
+    end
+
+    @named oscce = oscillator_ce()
+    eqs = [oscce.F ~ 0]
+    @named eqs_sys = ODESystem(eqs, t)
+    @named oneosc_ce = compose(eqs_sys, oscce)
+    oneosc_ce_simpl = structural_simplify(oneosc_ce)
+
+    prob = ODEProblem(oneosc_ce_simpl, [], (0.0, 2.0), [])
+    sol = solve(prob, Tsit5(), saveat = 0.1)
+
+    @test typeof(oneosc_ce_simpl) == ODESystem
+    @test sol[1, 6] < 1.0 # test whether x(t) decreases over time
+    @test sol[1, 18] > 0.5 # test whether event happened
+end