Improve error message for unsupported attribute for bridges (#2329)

Author: blegat

src/Bridges/bridge.jl

@@ -119,6 +119,17 @@ function MOI.supports(
     return false
 end
 
+function _attribute_error_message(attr, ::Type{B}, action) where {B}
+    return "Bridge of type `$(nameof(B))` does not support " *
+           "$action the attribute `$attr`. If you encountered this error " *
+           "unexpectedly, it probably means your model has been " *
+           "reformulated using the bridge, and you are attempting to query " *
+           "an attribute that we haven't implemented yet for this bridge. " *
+           "Please open an issue at https://github.com/jump-dev/MathOptInterface.jl/issues/new " *
+           "and provide a reproducible example explaining what you were " *
+           "trying to do."
+end
+
 """
     function MOI.get(
         model::MOI.ModelLike,
@@ -134,18 +145,8 @@ function MOI.get(
     attr::MOI.AbstractConstraintAttribute,
     bridge::AbstractBridge,
 )
-    return throw(
-        ArgumentError(
-            "Bridge of type `$(typeof(bridge))` does not support accessing " *
-            "the attribute `$attr`. If you encountered this error " *
-            "unexpectedly, it probably means your model has been " *
-            "reformulated using the bridge, and you are attempting to query " *
-            "an attribute that we haven't implemented yet for this bridge. " *
-            "Please open an issue at https://github.com/jump-dev/MathOptInterface.jl/issues/new " *
-            "and provide a reproducible example explaining what you were " *
-            "trying to do.",
-        ),
-    )
+    message = _attribute_error_message(attr, typeof(bridge), "accessing")
+    return throw(ArgumentError(message))
 end
 
 function MOI.get(
@@ -173,12 +174,14 @@ function MOI.set(
     model::MOI.ModelLike,
     attr::MOI.AbstractConstraintAttribute,
     bridge::AbstractBridge,
-    value,
+    ::Any,
 )
+    message =
+        _attribute_error_message(attr, typeof(bridge), "setting a value for")
     if MOI.is_copyable(attr) && !MOI.supports(model, attr, typeof(bridge))
-        throw(MOI.UnsupportedAttribute(attr))
+        return throw(MOI.UnsupportedAttribute(attr, message))
     else
-        throw(MOI.SetAttributeNotAllowed(attr))
+        return throw(MOI.SetAttributeNotAllowed(attr, message))
     end
 end
 

test/Bridges/Constraint/bridge.jl

@@ -26,17 +26,26 @@ struct DummyBridge <: MOI.Bridges.Constraint.AbstractBridge end
 function test_AbstractBridge()
     model = MOI.Utilities.Model{Float64}()
     bridge = DummyBridge()
-    attr = MOI.ConstraintPrimalStart()
-    @test !MOI.supports(model, attr, typeof(bridge))
-    @test_throws MOI.UnsupportedAttribute(attr) MOI.set(
-        model,
-        attr,
-        bridge,
-        1.0,
+    @test !MOI.supports(model, MOI.ConstraintPrimalStart(), typeof(bridge))
+    message = MOI.Bridges._attribute_error_message(
+        MOI.ConstraintPrimalStart(),
+        DummyBridge,
+        "setting a value for",
     )
-    attr = MOI.ConstraintFunction()
-    err = MOI.SetAttributeNotAllowed(attr)
-    @test_throws err MOI.set(model, attr, bridge, MOI.EqualTo(1.0))
+    @test_throws(
+        MOI.UnsupportedAttribute(MOI.ConstraintPrimalStart(), message),
+        MOI.set(model, MOI.ConstraintPrimalStart(), bridge, 1.0),
+    )
+    message = MOI.Bridges._attribute_error_message(
+        MOI.ConstraintSet(),
+        DummyBridge,
+        "setting a value for",
+    )
+    @test_throws(
+        MOI.SetAttributeNotAllowed(MOI.ConstraintSet(), message),
+        MOI.set(model, MOI.ConstraintSet(), bridge, MOI.EqualTo(1.0)),
+    )
+    return
 end
 
 end  # module

test/Bridges/bridge_optimizer.jl

@@ -218,7 +218,17 @@ MOI.Utilities.@model(
     (MOI.VectorAffineFunction, MOI.VectorQuadraticFunction)
 )
 
-function unsupported_constraint_attribute()
+struct AttributeNotAllowed <: MOI.AbstractConstraintAttribute end
+
+function MOI.supports(
+    ::MOI.ModelLike,
+    ::AttributeNotAllowed,
+    ::Type{<:MOI.Bridges.Constraint.SplitIntervalBridge},
+)
+    return true
+end
+
+function test_unsupported_constraint_attribute()
     mock = MOI.Utilities.MockOptimizer(NoIntervalModel{Float64}())
     bridged_mock = MOI.Bridges.Constraint.LessToGreater{Float64}(
         MOI.Bridges.Constraint.SplitInterval{Float64}(mock),
@@ -231,22 +241,19 @@ function unsupported_constraint_attribute()
         MOI.LessThan{Float64},
     }
     attr = MOI.Test.UnknownConstraintAttribute()
-    err = ArgumentError(
-        "Bridge of type `$(bridge)` does not support accessing " *
-        "the attribute `$attr`. If you encountered this error " *
-        "unexpectedly, it probably means your model has been " *
-        "reformulated using the bridge, and you are attempting to query " *
-        "an attribute that we haven't implemented yet for this bridge. " *
-        "Please open an issue at https://github.com/jump-dev/MathOptInterface.jl/issues/new " *
-        "and provide a reproducible example explaining what you were " *
-        "trying to do.",
-    )
+    message(action) = MOI.Bridges._attribute_error_message(attr, bridge, action)
     x = MOI.add_variable(bridged_mock)
     ci = MOI.add_constraint(bridged_mock, x, MOI.Interval(0.0, 1.0))
     @test !MOI.Bridges.is_bridged(bridged_mock, ci)
     @test MOI.Bridges.is_bridged(bridged_mock.model, ci)
     @test !MOI.supports(bridged_mock, attr, typeof(ci))
+    err = ArgumentError(message("accessing"))
     @test_throws err MOI.get(bridged_mock, attr, ci)
+    err = MOI.UnsupportedAttribute(attr, message("setting a value for"))
+    @test_throws err MOI.set(bridged_mock, attr, ci, 1)
+    attr = AttributeNotAllowed()
+    err = MOI.SetAttributeNotAllowed(attr, message("setting a value for"))
+    @test_throws err MOI.set(bridged_mock, attr, ci, 1)
     return
 end