From a6e7a0c8b82f71e40e3639c74b56e346b7907f17 Mon Sep 17 00:00:00 2001
From: LukasBarner <lukas.barner@tu-berlin.de>
Date: Sun, 7 Sep 2025 14:47:48 +0200
Subject: [PATCH 1/5] adds NonlinearizeBridge for objectives

---
 src/Bridges/Objective/Objective.jl            |  1 +
 .../bridges/FunctionConversionBridge.jl       | 28 +++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/src/Bridges/Objective/Objective.jl b/src/Bridges/Objective/Objective.jl
index 68be377bcb..0b2b7c9320 100644
--- a/src/Bridges/Objective/Objective.jl
+++ b/src/Bridges/Objective/Objective.jl
@@ -28,6 +28,7 @@ The coefficient type used is `T`.
 function add_all_bridges(model, ::Type{T}) where {T}
     MOI.Bridges.add_bridge(model, FunctionizeBridge{T})
     MOI.Bridges.add_bridge(model, QuadratizeBridge{T})
+    MOI.Bridges.add_bridge(model, NonlinearizeBridge{T})
     MOI.Bridges.add_bridge(model, SlackBridge{T})
     MOI.Bridges.add_bridge(model, VectorFunctionizeBridge{T})
     MOI.Bridges.add_bridge(model, VectorSlackBridge{T})
diff --git a/src/Bridges/Objective/bridges/FunctionConversionBridge.jl b/src/Bridges/Objective/bridges/FunctionConversionBridge.jl
index 92deb99bf9..fb0f4822fd 100644
--- a/src/Bridges/Objective/bridges/FunctionConversionBridge.jl
+++ b/src/Bridges/Objective/bridges/FunctionConversionBridge.jl
@@ -173,6 +173,34 @@ const QuadratizeBridge{T,G} =
 const Quadratize{T,OT<:MOI.ModelLike} =
     SingleBridgeOptimizer{QuadratizeBridge{T},OT}
 
+"""
+    NonlinearizeBridge{T,G} <: FunctionConversionBridge{T,MOI.ScalarNonlinearFunction,G}
+
+`NonlinearizeBridge` implements the following reformulations:
+
+ * ``\\min\\{x^\\top \\mathbf{𝑄} x + a^\\top x + b\\}`` into ``\\min\\{f(x)\\}``
+ * ``\\max\\{x^\\top \\mathbf{𝑄} x + a^\\top x + b\\}`` into ``\\max\\{f(x)\\}``
+
+where `f(x)` is a `MOI.ScalarNonlinearFunction`.
+
+## Source node
+
+`NonlinearizeBridge` supports:
+
+ * [`MOI.ObjectiveFunction{G}`](@ref)
+
+## Target nodes
+
+`NonlinearizeBridge` creates:
+
+ * One objective node: [`MOI.ObjectiveFunction{MOI.ScalarNonlinearFunction}`](@ref)
+"""
+const NonlinearizeBridge{T,G} =
+    FunctionConversionBridge{T,MOI.ScalarNonlinearFunction,G}
+
+const Nonlinearize{T,OT<:MOI.ModelLike} =
+    SingleBridgeOptimizer{NonlinearizeBridge{T},OT}
+
 """
     VectorFunctionizeBridge{T,G} <: FunctionConversionBridge{T,MOI.VectorAffineFunction{T},G}
 

From 0ce740a15e98b8c3eb47bc6c9b9965113472e954 Mon Sep 17 00:00:00 2001
From: LukasBarner <lukas.barner@tu-berlin.de>
Date: Sun, 7 Sep 2025 21:09:52 +0200
Subject: [PATCH 2/5] add tests and some fixes for tests...

---
 .../bridges/FunctionConversionBridge.jl       |   2 +-
 test/Bridges/Objective/NonlinearizeBridge.jl  | 113 ++++++++++++++++++
 test/Bridges/Objective/SlackBridge.jl         |   1 +
 test/Bridges/debug.jl                         |   1 +
 4 files changed, 116 insertions(+), 1 deletion(-)
 create mode 100644 test/Bridges/Objective/NonlinearizeBridge.jl

diff --git a/src/Bridges/Objective/bridges/FunctionConversionBridge.jl b/src/Bridges/Objective/bridges/FunctionConversionBridge.jl
index fb0f4822fd..7f525b2862 100644
--- a/src/Bridges/Objective/bridges/FunctionConversionBridge.jl
+++ b/src/Bridges/Objective/bridges/FunctionConversionBridge.jl
@@ -14,7 +14,7 @@
 
 for these pairs of functions:
 
- * [`MOI.ScalarAffineFunction`](@ref)` to [`MOI.ScalarQuadraticFunction`](@ref)
+ * [`MOI.ScalarAffineFunction`](@ref) to [`MOI.ScalarQuadraticFunction`](@ref)
  * [`MOI.ScalarQuadraticFunction`](@ref)  to [`MOI.ScalarNonlinearFunction`](@ref)
  * [`MOI.VectorAffineFunction`](@ref) to [`MOI.VectorQuadraticFunction`](@ref)
 
diff --git a/test/Bridges/Objective/NonlinearizeBridge.jl b/test/Bridges/Objective/NonlinearizeBridge.jl
new file mode 100644
index 0000000000..e57f49c2ac
--- /dev/null
+++ b/test/Bridges/Objective/NonlinearizeBridge.jl
@@ -0,0 +1,113 @@
+# Copyright (c) 2017: Miles Lubin and contributors
+# Copyright (c) 2017: Google Inc.
+#
+# Use of this source code is governed by an MIT-style license that can be found
+# in the LICENSE.md file or at https://opensource.org/licenses/MIT.
+
+module TestObjectiveNonlinearize
+
+using Test
+
+import MathOptInterface as MOI
+
+function runtests()
+    for name in names(@__MODULE__; all = true)
+        if startswith("$(name)", "test_")
+            @testset "$(name)" begin
+                getfield(@__MODULE__, name)()
+            end
+        end
+    end
+    return
+end
+
+include("../utilities.jl")
+
+function test_solve_singlevariable_obj()
+    mock = MOI.Utilities.MockOptimizer(MOI.Utilities.Model{Float64}())
+    model = MOI.Bridges.Objective.Nonlinearize{Float64}(mock)
+    MOI.Utilities.set_mock_optimize!(
+        mock,
+        (mock::MOI.Utilities.MockOptimizer) ->
+            MOI.Utilities.mock_optimize!(mock, [1.0], MOI.FEASIBLE_POINT),
+    )
+    MOI.Test.test_objective_ObjectiveFunction_duplicate_terms(
+        model,
+        MOI.Test.Config(;exclude = Any[MOI.DualObjectiveValue, MOI.ConstraintDual, ]),
+    )
+    @test MOI.get(mock, MOI.ObjectiveFunctionType()) ==
+          MOI.ScalarNonlinearFunction
+    @test MOI.get(model, MOI.ObjectiveFunctionType()) ==
+          MOI.ScalarAffineFunction{Float64}
+    @test MOI.get(mock, MOI.ObjectiveSense()) == MOI.MIN_SENSE
+    @test MOI.get(model, MOI.ObjectiveSense()) == MOI.MIN_SENSE
+    vis = MOI.get(model, MOI.ListOfVariableIndices())
+    func = 3.0 * vis[1] + 0.0
+    
+    @test MOI.get(
+        model,
+        MOI.ObjectiveFunction{MOI.ScalarAffineFunction{Float64}}(),
+    ) ≈ func
+    MOI.set(model, MOI.ObjectiveSense(), MOI.MAX_SENSE)
+    @test MOI.get(mock, MOI.ObjectiveSense()) == MOI.MAX_SENSE
+    @test MOI.get(model, MOI.ObjectiveSense()) == MOI.MAX_SENSE
+
+    _test_delete_objective(model, 1, tuple())
+    return
+end
+
+function test_solve_result_index()
+    mock = MOI.Utilities.MockOptimizer(MOI.Utilities.Model{Float64}())
+    model = MOI.Bridges.Objective.Nonlinearize{Float64}(mock)
+    MOI.Utilities.set_mock_optimize!(
+        mock,
+        (mock::MOI.Utilities.MockOptimizer) -> MOI.Utilities.mock_optimize!(
+            mock,
+            MOI.OPTIMAL,
+            (MOI.FEASIBLE_POINT, [1.0]),
+            MOI.FEASIBLE_POINT,
+            (MOI.VariableIndex, MOI.GreaterThan{Float64}) => [1.0],
+        ),
+    )
+    MOI.Test.test_solve_result_index(model, MOI.Test.Config(;exclude = Any[MOI.DualObjectiveValue, MOI.ConstraintDual, ]))
+
+    return
+end
+
+function test_runtests()
+    MOI.Bridges.runtests(
+        MOI.Bridges.Objective.NonlinearizeBridge,
+        model -> begin 
+            x = MOI.add_variable(model)
+            aff = MOI.ScalarAffineFunction(MOI.ScalarAffineTerm.([2.0], [x]), 1.0)
+            MOI.set(model, MOI.ObjectiveFunction{MOI.ScalarAffineFunction{Float64}}(), aff)
+            MOI.set(model, MOI.ObjectiveSense(), MOI.MIN_SENSE)
+        end,
+        model -> begin
+            x = MOI.add_variable(model)
+            exp = MOI.ScalarNonlinearFunction(:+, [MOI.ScalarNonlinearFunction(:*, [2.0, MOI.VariableIndex(1)]), 1.0])
+            MOI.set(model, MOI.ObjectiveFunction{MOI.ScalarNonlinearFunction}(), exp)
+            MOI.set(model, MOI.ObjectiveSense(), MOI.MIN_SENSE)
+        end,
+    )
+    MOI.Bridges.runtests(
+        MOI.Bridges.Objective.NonlinearizeBridge,
+        model -> begin 
+            x = MOI.add_variable(model)
+            aff = MOI.ScalarAffineFunction(MOI.ScalarAffineTerm.([2.0], [x]), 1.0)
+            MOI.set(model, MOI.ObjectiveFunction{MOI.ScalarAffineFunction{Float64}}(), aff)
+            MOI.set(model, MOI.ObjectiveSense(), MOI.MAX_SENSE)
+        end,
+        model -> begin
+            x = MOI.add_variable(model)
+            exp = MOI.ScalarNonlinearFunction(:+, [MOI.ScalarNonlinearFunction(:*, [2.0, MOI.VariableIndex(1)]), 1.0])
+            MOI.set(model, MOI.ObjectiveFunction{MOI.ScalarNonlinearFunction}(), exp)
+            MOI.set(model, MOI.ObjectiveSense(), MOI.MAX_SENSE)
+        end,
+    )
+    return
+end
+
+end  # module
+
+TestObjectiveNonlinearize.runtests()
\ No newline at end of file
diff --git a/test/Bridges/Objective/SlackBridge.jl b/test/Bridges/Objective/SlackBridge.jl
index 9757aae392..34c288ccc2 100644
--- a/test/Bridges/Objective/SlackBridge.jl
+++ b/test/Bridges/Objective/SlackBridge.jl
@@ -525,6 +525,7 @@ function test_complex_objective()
             MOI.Utilities.Model{Float64}(),
             Float64,
         )
+        MOI.Bridges.remove_bridge(dest, MOI.Bridges.Objective.NonlinearizeBridge{Float64}) # Otherwise, would be bridged to Nonlinear. 
         @test_throws MOI.UnsupportedAttribute(attr) MOI.copy_to(dest, model)
     end
     return
diff --git a/test/Bridges/debug.jl b/test/Bridges/debug.jl
index 9be0192e6d..d6e05544f9 100644
--- a/test/Bridges/debug.jl
+++ b/test/Bridges/debug.jl
@@ -188,6 +188,7 @@ end
 
 function test_print_active_bridges_objective_unsupported()
     model = MOI.Bridges.full_bridge_optimizer(Model{Float64}(), Float64)
+    MOI.Bridges.remove_bridge(model, MOI.Bridges.Objective.NonlinearizeBridge{Float64}) # Otherwise, Int would be bridged to Nonlinear.
     F = MOI.ScalarAffineFunction{Int}
     @test_throws(
         MOI.UnsupportedAttribute{MOI.ObjectiveFunction{F}},

From d15a0846d4e8e9328ba3b83fa1d226721e86c1de Mon Sep 17 00:00:00 2001
From: LukasBarner <lukas.barner@tu-berlin.de>
Date: Sun, 7 Sep 2025 21:14:52 +0200
Subject: [PATCH 3/5] formatting

---
 test/Bridges/Objective/NonlinearizeBridge.jl | 75 ++++++++++++++++----
 test/Bridges/Objective/SlackBridge.jl        |  5 +-
 test/Bridges/debug.jl                        |  5 +-
 3 files changed, 69 insertions(+), 16 deletions(-)

diff --git a/test/Bridges/Objective/NonlinearizeBridge.jl b/test/Bridges/Objective/NonlinearizeBridge.jl
index e57f49c2ac..ff4e8e0c11 100644
--- a/test/Bridges/Objective/NonlinearizeBridge.jl
+++ b/test/Bridges/Objective/NonlinearizeBridge.jl
@@ -33,7 +33,9 @@ function test_solve_singlevariable_obj()
     )
     MOI.Test.test_objective_ObjectiveFunction_duplicate_terms(
         model,
-        MOI.Test.Config(;exclude = Any[MOI.DualObjectiveValue, MOI.ConstraintDual, ]),
+        MOI.Test.Config(;
+            exclude = Any[MOI.DualObjectiveValue, MOI.ConstraintDual],
+        ),
     )
     @test MOI.get(mock, MOI.ObjectiveFunctionType()) ==
           MOI.ScalarNonlinearFunction
@@ -43,7 +45,7 @@ function test_solve_singlevariable_obj()
     @test MOI.get(model, MOI.ObjectiveSense()) == MOI.MIN_SENSE
     vis = MOI.get(model, MOI.ListOfVariableIndices())
     func = 3.0 * vis[1] + 0.0
-    
+
     @test MOI.get(
         model,
         MOI.ObjectiveFunction{MOI.ScalarAffineFunction{Float64}}(),
@@ -69,7 +71,12 @@ function test_solve_result_index()
             (MOI.VariableIndex, MOI.GreaterThan{Float64}) => [1.0],
         ),
     )
-    MOI.Test.test_solve_result_index(model, MOI.Test.Config(;exclude = Any[MOI.DualObjectiveValue, MOI.ConstraintDual, ]))
+    MOI.Test.test_solve_result_index(
+        model,
+        MOI.Test.Config(;
+            exclude = Any[MOI.DualObjectiveValue, MOI.ConstraintDual],
+        ),
+    )
 
     return
 end
@@ -77,31 +84,71 @@ end
 function test_runtests()
     MOI.Bridges.runtests(
         MOI.Bridges.Objective.NonlinearizeBridge,
-        model -> begin 
+        model -> begin
             x = MOI.add_variable(model)
-            aff = MOI.ScalarAffineFunction(MOI.ScalarAffineTerm.([2.0], [x]), 1.0)
-            MOI.set(model, MOI.ObjectiveFunction{MOI.ScalarAffineFunction{Float64}}(), aff)
+            aff = MOI.ScalarAffineFunction(
+                MOI.ScalarAffineTerm.([2.0], [x]),
+                1.0,
+            )
+            MOI.set(
+                model,
+                MOI.ObjectiveFunction{MOI.ScalarAffineFunction{Float64}}(),
+                aff,
+            )
             MOI.set(model, MOI.ObjectiveSense(), MOI.MIN_SENSE)
         end,
         model -> begin
             x = MOI.add_variable(model)
-            exp = MOI.ScalarNonlinearFunction(:+, [MOI.ScalarNonlinearFunction(:*, [2.0, MOI.VariableIndex(1)]), 1.0])
-            MOI.set(model, MOI.ObjectiveFunction{MOI.ScalarNonlinearFunction}(), exp)
+            exp = MOI.ScalarNonlinearFunction(
+                :+,
+                [
+                    MOI.ScalarNonlinearFunction(
+                        :*,
+                        [2.0, MOI.VariableIndex(1)],
+                    ),
+                    1.0,
+                ],
+            )
+            MOI.set(
+                model,
+                MOI.ObjectiveFunction{MOI.ScalarNonlinearFunction}(),
+                exp,
+            )
             MOI.set(model, MOI.ObjectiveSense(), MOI.MIN_SENSE)
         end,
     )
     MOI.Bridges.runtests(
         MOI.Bridges.Objective.NonlinearizeBridge,
-        model -> begin 
+        model -> begin
             x = MOI.add_variable(model)
-            aff = MOI.ScalarAffineFunction(MOI.ScalarAffineTerm.([2.0], [x]), 1.0)
-            MOI.set(model, MOI.ObjectiveFunction{MOI.ScalarAffineFunction{Float64}}(), aff)
+            aff = MOI.ScalarAffineFunction(
+                MOI.ScalarAffineTerm.([2.0], [x]),
+                1.0,
+            )
+            MOI.set(
+                model,
+                MOI.ObjectiveFunction{MOI.ScalarAffineFunction{Float64}}(),
+                aff,
+            )
             MOI.set(model, MOI.ObjectiveSense(), MOI.MAX_SENSE)
         end,
         model -> begin
             x = MOI.add_variable(model)
-            exp = MOI.ScalarNonlinearFunction(:+, [MOI.ScalarNonlinearFunction(:*, [2.0, MOI.VariableIndex(1)]), 1.0])
-            MOI.set(model, MOI.ObjectiveFunction{MOI.ScalarNonlinearFunction}(), exp)
+            exp = MOI.ScalarNonlinearFunction(
+                :+,
+                [
+                    MOI.ScalarNonlinearFunction(
+                        :*,
+                        [2.0, MOI.VariableIndex(1)],
+                    ),
+                    1.0,
+                ],
+            )
+            MOI.set(
+                model,
+                MOI.ObjectiveFunction{MOI.ScalarNonlinearFunction}(),
+                exp,
+            )
             MOI.set(model, MOI.ObjectiveSense(), MOI.MAX_SENSE)
         end,
     )
@@ -110,4 +157,4 @@ end
 
 end  # module
 
-TestObjectiveNonlinearize.runtests()
\ No newline at end of file
+TestObjectiveNonlinearize.runtests()
diff --git a/test/Bridges/Objective/SlackBridge.jl b/test/Bridges/Objective/SlackBridge.jl
index 34c288ccc2..4d9505e299 100644
--- a/test/Bridges/Objective/SlackBridge.jl
+++ b/test/Bridges/Objective/SlackBridge.jl
@@ -525,7 +525,10 @@ function test_complex_objective()
             MOI.Utilities.Model{Float64}(),
             Float64,
         )
-        MOI.Bridges.remove_bridge(dest, MOI.Bridges.Objective.NonlinearizeBridge{Float64}) # Otherwise, would be bridged to Nonlinear. 
+        MOI.Bridges.remove_bridge(
+            dest,
+            MOI.Bridges.Objective.NonlinearizeBridge{Float64},
+        ) # Otherwise, would be bridged to Nonlinear. 
         @test_throws MOI.UnsupportedAttribute(attr) MOI.copy_to(dest, model)
     end
     return
diff --git a/test/Bridges/debug.jl b/test/Bridges/debug.jl
index d6e05544f9..fe9a042ddb 100644
--- a/test/Bridges/debug.jl
+++ b/test/Bridges/debug.jl
@@ -188,7 +188,10 @@ end
 
 function test_print_active_bridges_objective_unsupported()
     model = MOI.Bridges.full_bridge_optimizer(Model{Float64}(), Float64)
-    MOI.Bridges.remove_bridge(model, MOI.Bridges.Objective.NonlinearizeBridge{Float64}) # Otherwise, Int would be bridged to Nonlinear.
+    MOI.Bridges.remove_bridge(
+        model,
+        MOI.Bridges.Objective.NonlinearizeBridge{Float64},
+    ) # Otherwise, Int would be bridged to Nonlinear.
     F = MOI.ScalarAffineFunction{Int}
     @test_throws(
         MOI.UnsupportedAttribute{MOI.ObjectiveFunction{F}},

From fc4e47fb0fec30d79ad7f1efcbef186db968e013 Mon Sep 17 00:00:00 2001
From: LukasBarner <lukas.barner@tu-berlin.de>
Date: Sun, 7 Sep 2025 21:33:07 +0200
Subject: [PATCH 4/5] rename NonlinearizeBridge to ToScalarNonlinearBridge

---
 src/Bridges/Objective/Objective.jl                 |  2 +-
 .../Objective/bridges/FunctionConversionBridge.jl  | 14 +++++++-------
 test/Bridges/Objective/SlackBridge.jl              |  2 +-
 ...nearizeBridge.jl => ToScalarNonlinearBridge.jl} | 12 ++++++------
 test/Bridges/debug.jl                              |  2 +-
 5 files changed, 16 insertions(+), 16 deletions(-)
 rename test/Bridges/Objective/{NonlinearizeBridge.jl => ToScalarNonlinearBridge.jl} (93%)

diff --git a/src/Bridges/Objective/Objective.jl b/src/Bridges/Objective/Objective.jl
index 0b2b7c9320..60ffcddf92 100644
--- a/src/Bridges/Objective/Objective.jl
+++ b/src/Bridges/Objective/Objective.jl
@@ -28,7 +28,7 @@ The coefficient type used is `T`.
 function add_all_bridges(model, ::Type{T}) where {T}
     MOI.Bridges.add_bridge(model, FunctionizeBridge{T})
     MOI.Bridges.add_bridge(model, QuadratizeBridge{T})
-    MOI.Bridges.add_bridge(model, NonlinearizeBridge{T})
+    MOI.Bridges.add_bridge(model, ToScalarNonlinearBridge{T})
     MOI.Bridges.add_bridge(model, SlackBridge{T})
     MOI.Bridges.add_bridge(model, VectorFunctionizeBridge{T})
     MOI.Bridges.add_bridge(model, VectorSlackBridge{T})
diff --git a/src/Bridges/Objective/bridges/FunctionConversionBridge.jl b/src/Bridges/Objective/bridges/FunctionConversionBridge.jl
index 7f525b2862..28cf74bd49 100644
--- a/src/Bridges/Objective/bridges/FunctionConversionBridge.jl
+++ b/src/Bridges/Objective/bridges/FunctionConversionBridge.jl
@@ -174,9 +174,9 @@ const Quadratize{T,OT<:MOI.ModelLike} =
     SingleBridgeOptimizer{QuadratizeBridge{T},OT}
 
 """
-    NonlinearizeBridge{T,G} <: FunctionConversionBridge{T,MOI.ScalarNonlinearFunction,G}
+    ToScalarNonlinearBridge{T,G} <: FunctionConversionBridge{T,MOI.ScalarNonlinearFunction,G}
 
-`NonlinearizeBridge` implements the following reformulations:
+`ToScalarNonlinearBridge` implements the following reformulations:
 
  * ``\\min\\{x^\\top \\mathbf{𝑄} x + a^\\top x + b\\}`` into ``\\min\\{f(x)\\}``
  * ``\\max\\{x^\\top \\mathbf{𝑄} x + a^\\top x + b\\}`` into ``\\max\\{f(x)\\}``
@@ -185,21 +185,21 @@ where `f(x)` is a `MOI.ScalarNonlinearFunction`.
 
 ## Source node
 
-`NonlinearizeBridge` supports:
+`ToScalarNonlinearBridge` supports:
 
  * [`MOI.ObjectiveFunction{G}`](@ref)
 
 ## Target nodes
 
-`NonlinearizeBridge` creates:
+`ToScalarNonlinearBridge` creates:
 
  * One objective node: [`MOI.ObjectiveFunction{MOI.ScalarNonlinearFunction}`](@ref)
 """
-const NonlinearizeBridge{T,G} =
+const ToScalarNonlinearBridge{T,G} =
     FunctionConversionBridge{T,MOI.ScalarNonlinearFunction,G}
 
-const Nonlinearize{T,OT<:MOI.ModelLike} =
-    SingleBridgeOptimizer{NonlinearizeBridge{T},OT}
+const ToScalarNonlinear{T,OT<:MOI.ModelLike} =
+    SingleBridgeOptimizer{ToScalarNonlinearBridge{T},OT}
 
 """
     VectorFunctionizeBridge{T,G} <: FunctionConversionBridge{T,MOI.VectorAffineFunction{T},G}
diff --git a/test/Bridges/Objective/SlackBridge.jl b/test/Bridges/Objective/SlackBridge.jl
index 4d9505e299..32bf8bae73 100644
--- a/test/Bridges/Objective/SlackBridge.jl
+++ b/test/Bridges/Objective/SlackBridge.jl
@@ -527,7 +527,7 @@ function test_complex_objective()
         )
         MOI.Bridges.remove_bridge(
             dest,
-            MOI.Bridges.Objective.NonlinearizeBridge{Float64},
+            MOI.Bridges.Objective.ToScalarNonlinearBridge{Float64},
         ) # Otherwise, would be bridged to Nonlinear. 
         @test_throws MOI.UnsupportedAttribute(attr) MOI.copy_to(dest, model)
     end
diff --git a/test/Bridges/Objective/NonlinearizeBridge.jl b/test/Bridges/Objective/ToScalarNonlinearBridge.jl
similarity index 93%
rename from test/Bridges/Objective/NonlinearizeBridge.jl
rename to test/Bridges/Objective/ToScalarNonlinearBridge.jl
index ff4e8e0c11..2a33005fb8 100644
--- a/test/Bridges/Objective/NonlinearizeBridge.jl
+++ b/test/Bridges/Objective/ToScalarNonlinearBridge.jl
@@ -4,7 +4,7 @@
 # Use of this source code is governed by an MIT-style license that can be found
 # in the LICENSE.md file or at https://opensource.org/licenses/MIT.
 
-module TestObjectiveNonlinearize
+module TestObjectiveToScalarNonlinear
 
 using Test
 
@@ -25,7 +25,7 @@ include("../utilities.jl")
 
 function test_solve_singlevariable_obj()
     mock = MOI.Utilities.MockOptimizer(MOI.Utilities.Model{Float64}())
-    model = MOI.Bridges.Objective.Nonlinearize{Float64}(mock)
+    model = MOI.Bridges.Objective.ToScalarNonlinear{Float64}(mock)
     MOI.Utilities.set_mock_optimize!(
         mock,
         (mock::MOI.Utilities.MockOptimizer) ->
@@ -60,7 +60,7 @@ end
 
 function test_solve_result_index()
     mock = MOI.Utilities.MockOptimizer(MOI.Utilities.Model{Float64}())
-    model = MOI.Bridges.Objective.Nonlinearize{Float64}(mock)
+    model = MOI.Bridges.Objective.ToScalarNonlinear{Float64}(mock)
     MOI.Utilities.set_mock_optimize!(
         mock,
         (mock::MOI.Utilities.MockOptimizer) -> MOI.Utilities.mock_optimize!(
@@ -83,7 +83,7 @@ end
 
 function test_runtests()
     MOI.Bridges.runtests(
-        MOI.Bridges.Objective.NonlinearizeBridge,
+        MOI.Bridges.Objective.ToScalarNonlinearBridge,
         model -> begin
             x = MOI.add_variable(model)
             aff = MOI.ScalarAffineFunction(
@@ -118,7 +118,7 @@ function test_runtests()
         end,
     )
     MOI.Bridges.runtests(
-        MOI.Bridges.Objective.NonlinearizeBridge,
+        MOI.Bridges.Objective.ToScalarNonlinearBridge,
         model -> begin
             x = MOI.add_variable(model)
             aff = MOI.ScalarAffineFunction(
@@ -157,4 +157,4 @@ end
 
 end  # module
 
-TestObjectiveNonlinearize.runtests()
+TestObjectiveToScalarNonlinear.runtests()
diff --git a/test/Bridges/debug.jl b/test/Bridges/debug.jl
index fe9a042ddb..5e71b8610a 100644
--- a/test/Bridges/debug.jl
+++ b/test/Bridges/debug.jl
@@ -190,7 +190,7 @@ function test_print_active_bridges_objective_unsupported()
     model = MOI.Bridges.full_bridge_optimizer(Model{Float64}(), Float64)
     MOI.Bridges.remove_bridge(
         model,
-        MOI.Bridges.Objective.NonlinearizeBridge{Float64},
+        MOI.Bridges.Objective.ToScalarNonlinearBridge{Float64},
     ) # Otherwise, Int would be bridged to Nonlinear.
     F = MOI.ScalarAffineFunction{Int}
     @test_throws(

From 27acba2846ca1425eac447ea6c4dceec5cf914e9 Mon Sep 17 00:00:00 2001
From: Oscar Dowson <o.dowson@gmail.com>
Date: Mon, 8 Sep 2025 10:24:39 +1200
Subject: [PATCH 5/5] Make conversion_cost to ScalarNonlinearFunction work only
 for Float64

---
 .../Constraint/bridges/AbstractFunctionConversionBridge.jl    | 4 ++--
 test/Bridges/Objective/SlackBridge.jl                         | 4 ----
 test/Bridges/debug.jl                                         | 4 ----
 3 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/src/Bridges/Constraint/bridges/AbstractFunctionConversionBridge.jl b/src/Bridges/Constraint/bridges/AbstractFunctionConversionBridge.jl
index 6d91ffe695..aff3fad8a2 100644
--- a/src/Bridges/Constraint/bridges/AbstractFunctionConversionBridge.jl
+++ b/src/Bridges/Constraint/bridges/AbstractFunctionConversionBridge.jl
@@ -269,8 +269,8 @@ function conversion_cost(
     ::Type{
         <:Union{
             MOI.VariableIndex,
-            MOI.ScalarAffineFunction,
-            MOI.ScalarQuadraticFunction,
+            MOI.ScalarAffineFunction{Float64},
+            MOI.ScalarQuadraticFunction{Float64},
         },
     },
 )
diff --git a/test/Bridges/Objective/SlackBridge.jl b/test/Bridges/Objective/SlackBridge.jl
index 32bf8bae73..9757aae392 100644
--- a/test/Bridges/Objective/SlackBridge.jl
+++ b/test/Bridges/Objective/SlackBridge.jl
@@ -525,10 +525,6 @@ function test_complex_objective()
             MOI.Utilities.Model{Float64}(),
             Float64,
         )
-        MOI.Bridges.remove_bridge(
-            dest,
-            MOI.Bridges.Objective.ToScalarNonlinearBridge{Float64},
-        ) # Otherwise, would be bridged to Nonlinear. 
         @test_throws MOI.UnsupportedAttribute(attr) MOI.copy_to(dest, model)
     end
     return
diff --git a/test/Bridges/debug.jl b/test/Bridges/debug.jl
index 5e71b8610a..9be0192e6d 100644
--- a/test/Bridges/debug.jl
+++ b/test/Bridges/debug.jl
@@ -188,10 +188,6 @@ end
 
 function test_print_active_bridges_objective_unsupported()
     model = MOI.Bridges.full_bridge_optimizer(Model{Float64}(), Float64)
-    MOI.Bridges.remove_bridge(
-        model,
-        MOI.Bridges.Objective.ToScalarNonlinearBridge{Float64},
-    ) # Otherwise, Int would be bridged to Nonlinear.
     F = MOI.ScalarAffineFunction{Int}
     @test_throws(
         MOI.UnsupportedAttribute{MOI.ObjectiveFunction{F}},