Re-add RELOG.write function

src/model.jl

@@ -280,10 +280,7 @@ function solve(instance::Instance;
     solution = get_solution(model, marginal_costs=marginal_costs)
     
     if output != nothing
-        @info "Writing solution: $output"
-        open(output, "w") do file
-            JSON.print(file, solution, 2)
-        end
+        write(solution, output)
     end
     
     return solution

src/reports.jl

@@ -255,6 +255,12 @@ function transportation_emissions_report(solution)::DataFrame
     return df
 end
 
+function write(solution::AbstractDict, filename::AbstractString)
+    @info "Writing solution: $filename"
+    open(filename, "w") do file
+        JSON.print(file, solution, 2)
+    end
+end
 
 write_plants_report(solution, filename) =
     CSV.write(filename, plants_report(solution))

test/model_test.jl

@@ -42,9 +42,15 @@ using RELOG, Cbc, JuMP, Printf, JSON, MathOptInterface.FileFormats
     end
 
     @testset "solve (exact)" begin
-        solution_filename = tempname()
+        solution_filename_a = tempname()
+        solution_filename_b = tempname()
         solution = RELOG.solve("$(pwd())/../instances/s1.json",
-                               output=solution_filename)
+                               output=solution_filename_a)
+
+        @test isfile(solution_filename_a)
+                               
+        RELOG.write(solution, solution_filename_b)
+        @test isfile(solution_filename_b)
         
         @test "Costs" in keys(solution)
         @test "Fixed operating (\$)" in keys(solution["Costs"])