Fix integration of compute_conflict through layers (jump-dev#1216)

* Fix integration of compute_conflict through layers

* Add test for bridged error

* Fix tests

Author: odow

src/Bridges/lazy_bridge_optimizer.jl

@@ -486,3 +486,7 @@ end
 function bridging_cost(b::LazyBridgeOptimizer, args...)
     return bridging_cost(b.graph, node(b, args...))
 end
+
+function MOI.compute_conflict!(model::LazyBridgeOptimizer)
+    return MOI.compute_conflict!(model.model)
+end

src/Utilities/cachingoptimizer.jl

@@ -1009,3 +1009,7 @@ function MOI.submit(
 end
 
 # TODO: get and set methods to look up/set name strings
+
+function MOI.compute_conflict!(model::CachingOptimizer)
+    return MOI.compute_conflict!(model.optimizer)
+end

src/Utilities/mockoptimizer.jl

@@ -133,7 +133,8 @@ function MOI.optimize!(mock::MockOptimizer)
     mock.hasdual = true
     return mock.optimize!(mock)
 end
-function MOI.compute_conflict!(::MockOptimizer) end
+
+MOI.compute_conflict!(::MockOptimizer) = nothing
 
 function throw_mock_unsupported_names(attr)
     return throw(MOI.UnsupportedAttribute(
@@ -305,13 +306,15 @@ function MOI.set(
 )
     return _safe_set_result(mock.con_basis, attr, idx, value)
 end
+
 function MOI.set(
     mock::MockOptimizer,
     ::MOI.ConstraintConflictStatus,
     idx::MOI.ConstraintIndex,
     value,
 )
-    return mock.constraint_conflict_status[idx] = value
+    mock.constraint_conflict_status[idx] = value
+    return
 end
 
 MOI.get(mock::MockOptimizer, ::MOI.RawSolver) = mock
@@ -529,6 +532,7 @@ function MOI.get(
     MOI.throw_if_not_valid(mock, idx)
     return _safe_get_result(mock.con_basis, attr, idx, "basis status")
 end
+
 function MOI.get(
     mock::MockOptimizer,
     ::MOI.ConstraintConflictStatus,

test/attributes.jl

@@ -30,3 +30,68 @@
                                  ones(2))
     end
 end
+
+@testset "test_integration_compute_conflict" begin
+    optimizer = MOI.Utilities.MockOptimizer(MOI.Utilities.Model{Float64}())
+    model = MOI.Utilities.CachingOptimizer(
+        MOI.Utilities.Model{Float64}(),
+        MOI.Bridges.full_bridge_optimizer(optimizer, Float64),
+    )
+    x = MOI.add_variable(model)
+    c1 = MOI.add_constraint(model, MOI.SingleVariable(x), MOI.LessThan(0.0))
+    c2 = MOI.add_constraint(model, MOI.SingleVariable(x), MOI.GreaterThan(1.0))
+    MOI.optimize!(model)
+    @test MOI.get(optimizer, MOI.ConflictStatus()) == MOI.COMPUTE_CONFLICT_NOT_CALLED
+    MOI.set(optimizer, MOI.ConflictStatus(), MOI.CONFLICT_FOUND)
+    MOI.set(
+        optimizer,
+        MOI.ConstraintConflictStatus(),
+        MOI.get(
+            optimizer,
+            MOI.ListOfConstraintIndices{MOI.SingleVariable,MOI.LessThan{Float64}}(),
+        )[1],
+        MOI.NOT_IN_CONFLICT,
+    )
+    MOI.set(
+        optimizer,
+        MOI.ConstraintConflictStatus(),
+        MOI.get(
+            optimizer,
+            MOI.ListOfConstraintIndices{MOI.SingleVariable,MOI.GreaterThan{Float64}}(),
+        )[1],
+        MOI.IN_CONFLICT,
+    )
+    MOI.compute_conflict!(model)
+    @test MOI.get(model, MOI.ConflictStatus()) == MOI.CONFLICT_FOUND
+    @test MOI.get(model, MOI.ConstraintConflictStatus(), c1) == MOI.NOT_IN_CONFLICT
+    @test MOI.get(model, MOI.ConstraintConflictStatus(), c2) == MOI.IN_CONFLICT
+end
+
+MOI.Utilities.@model(
+    OnlyScalarConstraints,
+    (),
+    (MOI.GreaterThan, MOI.LessThan),
+    (),
+    (),
+    (),
+    (MOI.ScalarAffineFunction,),
+    (),
+    ()
+)
+
+@testset "test_integration_compute_conflict" begin
+    optimizer = MOI.Utilities.MockOptimizer(OnlyScalarConstraints{Float64}())
+    model = MOI.Bridges.full_bridge_optimizer(optimizer, Float64)
+    x = MOI.add_variable(model)
+    c = MOI.add_constraint(
+        model,
+        MOI.ScalarAffineFunction([MOI.ScalarAffineTerm(1.0, x)], 0.0),
+        MOI.Interval(0.0, 1.0),
+    )
+    MOI.optimize!(model)
+    @test MOI.get(optimizer, MOI.ConflictStatus()) == MOI.COMPUTE_CONFLICT_NOT_CALLED
+    MOI.set(optimizer, MOI.ConflictStatus(), MOI.CONFLICT_FOUND)
+    MOI.compute_conflict!(model)
+    @test MOI.get(model, MOI.ConflictStatus()) == MOI.CONFLICT_FOUND
+    @test_throws ArgumentError MOI.get(model, MOI.ConstraintConflictStatus(), c)
+end