fix: fix discrete callback condition with array variable

src/systems/callbacks.jl

@@ -550,7 +550,7 @@ end
 """
     compile_condition(cb::SymbolicDiscreteCallback, sys, dvs, ps; expression, kwargs...)
 
-Returns a function `condition(u,p,t)` returning the `condition(cb)`.
+Returns a function `condition(u,t,integrator)` returning the `condition(cb)`.
 
 Notes
 
@@ -571,7 +571,8 @@ function compile_condition(cb::SymbolicDiscreteCallback, sys, dvs, ps;
     end
     expr = build_function(
         condit, u, t, p...; expression = Val{true},
-        wrap_code = condition_header(sys) .∘ wrap_array_vars(sys, condit; dvs, ps) .∘
+        wrap_code = condition_header(sys) .∘
+                    wrap_array_vars(sys, condit; dvs, ps, inputs = true) .∘
                     wrap_parameter_dependencies(sys, !(condit isa AbstractArray)),
         kwargs...)
     if expression == Val{true}

test/dde.jl

@@ -74,7 +74,7 @@ pmul = [1.0,
 
 prob = SDDEProblem(hayes_modelf, hayes_modelg, [1.0], h, tspan, pmul;
     constant_lags = (pmul[1],));
-sol = solve(prob, RKMil())
+sol = solve(prob, RKMil(), seed = 100)
 
 @variables x(..)
 @parameters a=-4.0 b=-2.0 c=10.0 α=-1.3 β=-1.2 γ=1.1
@@ -87,7 +87,7 @@ eqs = [D(x(t)) ~ a * x(t) + b * x(t - τ) + c + (α * x(t) + γ) * η]
 @test equations(sys) == [D(x(t)) ~ a * x(t) + b * x(t - τ) + c]
 @test isequal(ModelingToolkit.get_noiseeqs(sys), [α * x(t) + γ])
 prob_mtk = SDDEProblem(sys, [x(t) => 1.0 + t], tspan; constant_lags = (τ,));
-@test_nowarn sol_mtk = solve(prob_mtk, RKMil())
+@test_nowarn sol_mtk = solve(prob_mtk, RKMil(), seed = 100)
 
 prob_sa = SDDEProblem(
     sys, [x(t) => 1.0 + t], tspan; constant_lags = (τ,), u0_constructor = SVector{1})

test/symbolic_events.jl

@@ -1075,3 +1075,24 @@ end
     prob = ODEProblem(pend, [x => 1], (0.0, 3.0), guesses = [y => x])
     @test all(≈(0.0; atol = 1e-9), solve(prob, Rodas5())[[x, y]][end])
 end
+
+@testset "Issue#3154 Array variable in discrete condition" begin
+    @mtkmodel DECAY begin
+        @parameters begin
+            unrelated[1:2] = zeros(2)
+            k = 0.0
+        end
+        @variables begin
+            x(t) = 10.0
+        end
+        @equations begin
+            D(x) ~ -k * x
+        end
+        @discrete_events begin
+            (t == 1.0) => [k ~ 1.0]
+        end
+    end
+    @mtkbuild decay = DECAY()
+    prob = ODEProblem(decay, [], (0.0, 10.0), [])
+    @test_nowarn solve(prob, Tsit5(), tstops = [1.0])
+end