Refactor test_attribute_VariableBridgingCost function

Refactor test for VariableBridgingCost to improve clarity and maintainability.

Author: odow

src/Test/test_attribute.jl

@@ -392,25 +392,28 @@ function test_attribute_unsupported_constraint(model::MOI.ModelLike, ::Config)
     return
 end
 
+version_added(::typeof(test_attribute_unsupported_constraint)) = v"1.9.0"
+
 """
     test_attribute_VariableBridgingCost(model::MOI.ModelLike, config::Config)
 
 Test that, for every set `S` that the model claims to support via
 `supports_add_constrained_variable(s)`, the corresponding
 [`MOI.VariableBridgingCost`](@ref) attribute returns a finite value.
 
-This is the variable-side analogue of the
-`ConstraintBridgingCost` check in `_basic_constraint_test_helper`.
-The fallback works for most model but it may need
-custom method for some MOI layer (see
-https://github.com/jump-dev/MathOptInterface.jl/pull/3001#issuecomment-4468198935)
+This is the variable-side analog of the `ConstraintBridgingCost` check in
+`_basic_constraint_test_helper`.
+
+The fallback works for most model but it may need custom method for some MOI
+layers (see https://github.com/jump-dev/MathOptInterface.jl/pull/3001#issuecomment-4468198935).
+
 This test is here to catch that.
 """
 function test_attribute_VariableBridgingCost(
     model::MOI.ModelLike,
     ::Config{T},
 ) where {T}
-    scalar_sets = Type{<:MOI.AbstractScalarSet}[
+    for S in Any[
         MOI.GreaterThan{T},
         MOI.LessThan{T},
         MOI.EqualTo{T},
@@ -420,7 +423,11 @@ function test_attribute_VariableBridgingCost(
         MOI.Semicontinuous{T},
         MOI.Semiinteger{T},
     ]
-    vector_sets = Type{<:MOI.AbstractVectorSet}[
+        if MOI.supports_add_constrained_variable(model, S)
+            @test MOI.get(model, MOI.VariableBridgingCost{S}()) < Inf
+        end
+    end
+    for S in Any[
         MOI.Reals,
         MOI.Zeros,
         MOI.Nonnegatives,
@@ -430,12 +437,6 @@ function test_attribute_VariableBridgingCost(
         MOI.ExponentialCone,
         MOI.PositiveSemidefiniteConeTriangle,
     ]
-    for S in scalar_sets
-        if MOI.supports_add_constrained_variable(model, S)
-            @test MOI.get(model, MOI.VariableBridgingCost{S}()) < Inf
-        end
-    end
-    for S in vector_sets
         if MOI.supports_add_constrained_variables(model, S)
             @test MOI.get(model, MOI.VariableBridgingCost{S}()) < Inf
         end
@@ -444,5 +445,3 @@ function test_attribute_VariableBridgingCost(
 end
 
 version_added(::typeof(test_attribute_VariableBridgingCost)) = v"1.52.0"
-
-version_added(::typeof(test_attribute_unsupported_constraint)) = v"1.9.0"