use demo for tests

Project.toml

@@ -23,7 +23,8 @@ Preferences = "1"
 julia = "1.6"
 
 [extras]
+Printf = "de0858da-6303-5e67-8744-51eddeeeb8d7"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["Test"]
+test = ["Printf","Test"]

demo/demo.jl

@@ -63,6 +63,14 @@ ImGuiGLFWBackend.init(glfw_ctx)
 opengl_ctx = ImGuiOpenGLBackend.create_context(glsl_version)
 ImGuiOpenGLBackend.init(opengl_ctx)
 
+# for tests
+if haskey(ENV, "AUTO_CLOSE_DEMO")
+    tsecs = parse(Int, ENV["AUTO_CLOSE_DEMO"])
+    Timer(tsecs) do t
+        glfwSetWindowShouldClose(window, true)
+    end
+end
+
 try
     show_demo_window = true
     show_another_window = false
@@ -112,14 +120,16 @@ try
         glfwGetFramebufferSize(window, width, height)
         display_w = width[]
         display_h = height[]
-        
+
         glViewport(0, 0, display_w, display_h)
         glClearColor(clear_color...)
         glClear(GL_COLOR_BUFFER_BIT)
         ImGuiOpenGLBackend.render(opengl_ctx) #ImGui_ImplOpenGL3_RenderDrawData(CImGui.GetDrawData())
 
         glfwMakeContextCurrent(window)
         glfwSwapBuffers(window)
+
+        yield() # to allow shutdown timer to run
     end
 catch e
     @error "Error in renderloop!" exception=e

test/runtests.jl

@@ -2,5 +2,7 @@ using CImGui
 using Test
 
 @testset "CImGui.jl" begin
-    # Write your own tests here.
+    withenv("AUTO_CLOSE_DEMO" => "5") do
+        include(joinpath("..", "demo", "demo.jl"))
+    end
 end