Update

Author: odow

src/Utilities/print.jl

@@ -683,13 +683,25 @@ end
 
 Base.show(io::IO, ::MIME"text/latex", model::_LatexModel) = show(io, model)
 
-function Base.print(model::MOI.ModelLike; kwargs...)
+function _get_ijulia_latex_display()
     for d in Base.Multimedia.displays
         if Base.Multimedia.displayable(d, "text/latex") &&
            startswith("$(typeof(d))", "IJulia.")
-            return display(d, "text/latex", latex_formulation(model; kwargs...))
+            return d
         end
     end
+    return
+end
+
+function Base.print(
+    model::MOI.ModelLike;
+    _latex_display = _get_ijulia_latex_display(),
+    kwargs...,
+)
+    if _latex_display !== nothing
+        formulation = latex_formulation(model; kwargs...)
+        return display(_latex_display, "text/latex", formulation)
+    end
     return print(stdout, model; kwargs...)
 end
 

test/Utilities/print.jl

@@ -724,6 +724,32 @@ function test_show_2505()
     return
 end
 
+function test_print_model_to_stdout()
+    model = MOI.Utilities.Model{Float64}()
+    dir = mktempdir()
+    d = MOI.Utilities._get_ijulia_latex_display()
+    # d is only not nothing if IJulia is running.
+    if d === nothing
+        open(joinpath(dir, "stdout.log"), "w") do io
+            redirect_stdout(io) do
+                print(model)
+                return
+            end
+            return
+        end
+        @test read(joinpath(dir, "stdout.log"), String) ==
+              "Feasibility\n\nSubject to:\n"
+    end
+    io = IOBuffer()
+    d = Base.Multimedia.TextDisplay(io)
+    @test Base.Multimedia.displayable(d, "text/latex")
+    print(model; _latex_display = d)
+    seekstart(io)
+    @test read(io, String) ==
+          "\$\$ \\begin{aligned}\n\\text{feasibility}\\\\\n\\text{Subject to}\\\\\n\\end{aligned} \$\$\n"
+    return
+end
+
 end
 
 TestPrint.runtests()

test/attributes.jl

@@ -375,7 +375,7 @@ end
 function test_showerror_OptimizeInProgress()
     err = MOI.OptimizeInProgress(MOI.VariablePrimal())
     @test sprint(showerror, err) ==
-          "$err: Cannot get result as the `MOI.optimize!` has not finished."
+          "$(typeof(err)): Cannot get result as the `MOI.optimize!` has not finished."
     return
 end