Transfer some test utility function into DynamicPPL (#2049)

* Update OptimInterface.jl

* Only run optimisation tests in numerical stage.

* fix function lookup after moving functions

---------

Co-authored-by: Xianda Sun <[email protected]>

Author: yebai

test/modes/OptimInterface.jl

@@ -1,38 +1,3 @@
-# TODO: Remove these once the equivalent is present in `DynamicPPL.TestUtils.
-function likelihood_optima(::DynamicPPL.TestUtils.UnivariateAssumeDemoModels)
-    return (s=1/16, m=7/4)
-end
-function posterior_optima(::DynamicPPL.TestUtils.UnivariateAssumeDemoModels)
-    # TODO: Figure out exact for `s`.
-    return (s=0.907407, m=7/6)
-end
-
-function likelihood_optima(model::DynamicPPL.TestUtils.MultivariateAssumeDemoModels)
-    # Get some containers to fill.
-    vals = Random.rand(model)
-
-    # NOTE: These are "as close to zero as we can get".
-    vals.s[1] = 1e-32
-    vals.s[2] = 1e-32
-
-    vals.m[1] = 1.5
-    vals.m[2] = 2.0
-
-    return vals
-end
-function posterior_optima(model::DynamicPPL.TestUtils.MultivariateAssumeDemoModels)
-    # Get some containers to fill.
-    vals = Random.rand(model)
-
-    # TODO: Figure out exact for `s[1]`.
-    vals.s[1] = 0.890625
-    vals.s[2] = 1
-    vals.m[1] = 3/4
-    vals.m[2] = 1
-
-    return vals
-end
-
 # Used for testing how well it works with nested contexts.
 struct OverrideContext{C,T1,T2} <: DynamicPPL.AbstractContext
     context::C
@@ -57,7 +22,7 @@ function DynamicPPL.tilde_observe(context::OverrideContext, right, left, vi)
     return context.loglikelihood_weight, vi
 end
 
-@testset "OptimInterface.jl" begin
+@numerical_testset "OptimInterface.jl" begin
     @testset "MLE" begin
         Random.seed!(222)
         true_value = [0.0625, 1.75]
@@ -157,7 +122,7 @@ end
     # FIXME: Some models doesn't work for Tracker and ReverseDiff.
     if Turing.Essential.ADBACKEND[] === :forwarddiff
         @testset "MAP for $(model.f)" for model in DynamicPPL.TestUtils.DEMO_MODELS
-            result_true = posterior_optima(model)
+            result_true = DynamicPPL.TestUtils.posterior_optima(model)
 
             @testset "$(nameof(typeof(optimizer)))" for optimizer in [LBFGS(), NelderMead()]
                 result = optimize(model, MAP(), optimizer)
@@ -188,7 +153,7 @@ end
             DynamicPPL.TestUtils.demo_dot_assume_matrix_dot_observe_matrix,
         ]
         @testset "MLE for $(model.f)" for model in DynamicPPL.TestUtils.DEMO_MODELS
-            result_true = likelihood_optima(model)
+            result_true = DynamicPPL.TestUtils.likelihood_optima(model)
 
             # `NelderMead` seems to struggle with convergence here, so we exclude it.
             @testset "$(nameof(typeof(optimizer)))" for optimizer in [LBFGS(),]