Implement UnitCommitment.write

docs/usage.md

@@ -52,11 +52,11 @@ model = UnitCommitment.build_model(
 # Solve model
 UnitCommitment.optimize!(model)
 
-# Extract solution and write it to a file
+# Extract solution
 solution = UnitCommitment.solution(model)
-open("/path/to/output.json", "w") do file
-    JSON.print(file, solution, 2)
-end
+
+# Write solution to a file
+UnitCommitment.write("/path/to/output.json", solution)
 ```
 
 ### Solving benchmark instances

src/model.jl

@@ -578,7 +578,14 @@ function solution(model::JuMP.Model)
 end
 
 
-function fix!(model::JuMP.Model, solution)::Nothing
+function write(filename::AbstractString, solution::AbstractDict)::Nothing
+    open(filename, "w") do file
+        JSON.print(file, solution, 2)
+    end    
+end
+
+
+function fix!(model::JuMP.Model, solution::AbstractDict)::Nothing
     instance, T = model[:instance], model[:instance].time
     is_on = model[:is_on]
     prod_above = model[:prod_above]
@@ -600,7 +607,7 @@ function fix!(model::JuMP.Model, solution)::Nothing
 end
 
 
-function set_warm_start!(model::JuMP.Model, solution)::Nothing
+function set_warm_start!(model::JuMP.Model, solution::AbstractDict)::Nothing
     instance, T = model[:instance], model[:instance].time
     is_on = model[:is_on]
     prod_above = model[:prod_above]

test/model_test.jl

@@ -16,15 +16,18 @@ using UnitCommitment, LinearAlgebra, Cbc, JuMP
             optimizer=optimizer,
             variable_names=true,
         )
-
         @test name(model[:is_on]["g1", 1]) == "is_on[g1,1]"
 
-        JuMP.write_to_file(model, "test.mps")
-
         # Optimize and retrieve solution
         UnitCommitment.optimize!(model)
         solution = UnitCommitment.solution(model)
 
+        # Write solution to a file
+        filename = tempname()
+        UnitCommitment.write(filename, solution)
+        loaded = JSON.parsefile(filename)
+        @test length(loaded["Is on"]) == 6
+        
         # Verify solution
         @test UnitCommitment.validate(instance, solution)