Convert AbstractString to String in set_attribute (#3840)

.github/workflows/documentation.yml

@@ -14,7 +14,7 @@ jobs:
  - uses: actions/checkout@v4
  - uses: julia-actions/setup-julia@latest
  with:
- version: '1'
+ version: '1.10'
  - name: Install dependencies
  shell: julia --color=yes --project=docs/ {0}
  run: |

src/optimizer_interface.jl

@@ -1251,6 +1251,26 @@ function get_attribute(
  return get_attribute(model, String(name))
 end
 
+# Some MOI attributes have a strict value type, like ::String or ::Float64, but
+# users may pass other generic subtypes, like SubString instead of String.
+# Rather than throw obtuse errors, we can catch and fix some common cases. We
+# shouldn't fix every case (for example, AbstractString -> String) because
+# users might intentionally want the other subtype.
+#
+# The default case is to do nothing:
+_to_concrete_value_type_if_needed(::MOI.AnyAttribute, value) = value
+
+# A common case is passing an AbstractString instead of a String.
+function _to_concrete_value_type_if_needed(
+ attr::MOI.AnyAttribute,
+ value::AbstractString,
+)
+ if !(value isa String) && MOI.attribute_value_type(attr) === String
+ return String(value)
+ end
+ return value
+end
+
 """
  set_attribute(model::GenericModel, attr::MOI.AbstractModelAttribute, value)
  set_attribute(x::GenericVariableRef, attr::MOI.AbstractVariableAttribute, value)
@@ -1285,7 +1305,7 @@ function set_attribute(
  attr::MOI.AbstractModelAttribute,
  value,
 )
- MOI.set(model, attr, value)
+ MOI.set(model, attr, _to_concrete_value_type_if_needed(attr, value))
  return
 end
 
@@ -1294,7 +1314,8 @@ function set_attribute(
  attr::MOI.AbstractVariableAttribute,
  value,
 )
- MOI.set(owner_model(x), attr, x, value)
+ model = owner_model(x)
+ MOI.set(model, attr, x, _to_concrete_value_type_if_needed(attr, value))
  return
 end
 
@@ -1303,7 +1324,8 @@ function set_attribute(
  attr::MOI.AbstractConstraintAttribute,
  value,
 )
- MOI.set(owner_model(cr), attr, cr, value)
+ model = owner_model(cr)
+ MOI.set(model, attr, cr, _to_concrete_value_type_if_needed(attr, value))
  return
 end
 
@@ -1344,7 +1366,7 @@ function set_attribute(
  attr::MOI.AbstractOptimizerAttribute,
  value,
 )
- MOI.set(model, attr, value)
+ MOI.set(model, attr, _to_concrete_value_type_if_needed(attr, value))
  return
 end
 

test/test_model.jl

@@ -1313,4 +1313,29 @@ function test_is_solved_and_feasible()
  return
 end
 
+function test_set_abstract_string()
+ abstract_string = split("foo.bar", ".")[1]
+ model = Model() do
+ return MOI.Utilities.MockOptimizer(
+ MOI.Utilities.UniversalFallback(MOI.Utilities.Model{Float64}()),
+ )
+ end
+ set_attribute(model, MOI.Name(), abstract_string)
+ @test get_attribute(model, MOI.Name()) == "foo"
+ @variable(model, x)
+ set_attribute(x, MOI.VariableName(), abstract_string)
+ ret = get_attribute(x, MOI.VariableName())
+ @test ret isa String && ret == "foo"
+ c = @constraint(model, 2x >= 1)
+ set_attribute(c, MOI.ConstraintName(), abstract_string)
+ ret = get_attribute(c, MOI.ConstraintName())
+ @test ret isa String && ret == "foo"
+ set_attribute(model, abstract_string, abstract_string)
+ ret = get_attribute(model, abstract_string)
+ # This `ret` is NOT a `::String` because we don't know the value type of the
+ # attribute.
+ @test ret isa typeof(abstract_string) && ret == "foo"
+ return
+end
+
 end # module TestModels