Added delete extension for link constraints

src/optiedge.jl

@@ -76,6 +76,24 @@ function JuMP.all_variables(edge::OptiEdge)
     return unique(vars)
 end
 
+function JuMP.delete(graph::OptiGraph, cref::ConstraintRef)
+    if typeof(JuMP.owner_model(cref)) == OptiNode{OptiGraph}
+        error(
+            "You have passed a node constraint but specified an OptiGraph." *
+            "Use `JuMP.delete(::OptiNode, ::ConstraintRef)` instead",
+        )
+    end
+    if graph !== source_graph(JuMP.owner_model(cref))
+        error(
+            "The constraint reference you are trying to delete does not" *
+            "belong to the specified graph",
+        )
+    end
+    _set_dirty(graph)
+    MOI.delete(JuMP.owner_model(cref), cref)
+    #TODO: Probably need to delete the edge altogether if it is the only constraint on the edge
+end
+
 ### Edge Constraints
 
 # NOTE: could use one method for node and edge

src/optigraph.jl

@@ -1423,3 +1423,7 @@ function _set_objective_coefficient(
     )
     return nothing
 end
+
+function _set_dirty(graph::OptiGraph)
+    graph.is_model_dirty = true
+end

test/test_optigraph.jl

@@ -440,6 +440,24 @@ function test_nlp_exceptions()
     @test_throws Exception @NLconstraint(graph, graph[1][:x]^3 >= 0)
 end
 
+function test_delete_extensions()
+    graph = OptiGraph()
+    @optinode(graph, nodes[1:2])
+
+    @variable(nodes[1], x >= 1)
+    @variable(nodes[2], x >= 2)
+    @constraint(nodes[1], n_con, nodes[1][:x]^2 >= 1)
+    @linkconstraint(graph, l_con, nodes[1][:x] + nodes[2][:x] == 4)
+
+    @test_throws ErrorException JuMP.delete(graph, n_con)
+    @test_throws ErrorException JuMP.delete(nodes[1], l_con)
+
+    JuMP.delete(nodes[1], n_con)
+    @test !(n_con in all_constraints(nodes[1]))
+    JuMP.delete(graph, l_con)
+    @test !(l_con in all_link_constraints(graph))
+end
+
 function run_tests()
     for name in names(@__MODULE__; all=true)
         if !startswith("$(name)", "test_")