test: call info2debugstr function for coverage

Author: franckgaga

test/test_predictive_control.jl

@@ -82,6 +82,7 @@ end
     mpc4  = LinMPC(model2)
     preparestate!(mpc4, [0])
     moveinput!(mpc4, [0]) ≈ [0.0]
+    @test_nowarn ModelPredictiveControl.info2debugstr(info)
 
     @test_throws DimensionMismatch moveinput!(mpc1, [0,0,0])
     @test_throws DimensionMismatch moveinput!(mpc1, [0], [0,0])
@@ -407,6 +408,7 @@ end
     mpc4  = ExplicitMPC(model2)
     preparestate!(mpc4, [0])
     moveinput!(mpc4, [0]) ≈ [0.0]
+    @test_nowarn ModelPredictiveControl.info2debugstr(info)
 end
 
 
@@ -633,6 +635,7 @@ end
     nonlinmodel2.h!(y, Float32[0,0], Float32[0], Float32[])
     preparestate!(nmpc7, [0], [0])
     @test moveinput!(nmpc7, [0], [0]) ≈ [0.0]
+    @test_nowarn ModelPredictiveControl.info2debugstr(info)
 end
 
 @testset "NonLinMPC step disturbance rejection" begin

test/test_state_estim.jl

@@ -973,6 +973,7 @@ end
     info = getinfo(mhe5)
     @test info[:x̂] ≈ x̂ atol=1e-9
     @test info[:Ŷ][end-1:end] ≈ [50, 30] atol=1e-9
+    @test_nowarn ModelPredictiveControl.info2debugstr(info)
 end
 
 @testset "MovingHorizonEstimator fallbacks for arrival covariance estimation" begin