add Aggregate test

EpiAware/test/EpiObsModels/modifiers/Aggregate.jl

@@ -0,0 +1,30 @@
+@testitem "Aggregate constructor works as expected" begin
+    weekly_agg = Aggregate(PoissonError(), [0, 0, 0, 0, 7, 0, 0])
+    @test weekly_agg.model == PoissonError()
+    @test weekly_agg.aggregation == [0, 0, 0, 0, 7, 0, 0]
+    @test weekly_agg.present == [false, false, false, false, true, false, false]
+
+    weekly_agg = Aggregate(model = PoissonError(), aggregation = [0, 0, 0, 0, 7, 0, 0])
+    @test weekly_agg.model == PoissonError()
+    @test weekly_agg.aggregation == [0, 0, 0, 0, 7, 0, 0]
+end
+
+@testitem "Aggregate generate_observations works as expected" begin
+    using Turing
+    struct TestObs <: AbstractTuringObservationModel end
+
+    @model function EpiAwareBase.generate_observations(::TestObs, y_t, Y_t)
+        return Y_t
+    end
+    weekly_agg = Aggregate(TestObs(), [0, 0, 0, 0, 7, 0, 0])
+    gen_obs = generate_observations(weekly_agg, missing, fill(1, 28))
+    draws = gen_obs()
+    @test draws isa Vector{Float64}
+    @test length(draws) == 28
+    exp_draws = fill(0.0, 28)
+    exp_draws[5] = 5.0
+    exp_draws[12] = 7.0
+    exp_draws[19] = 7.0
+    exp_draws[26] = 7.0
+    @test draws == exp_draws
+end