test explicit stdout/stderr printing

test/stdio.jl

@@ -1,13 +1,16 @@
 using Compat.Test
 using IJulia
+using Compat: occursin
 
 mktemp() do path, io
     redirect_stdout(IJulia.IJuliaStdio(io, "stdout")) do
+        stdout = isdefined(Base, :devnull) ? Base.stdout : Base.STDOUT
+        println(stdout, "stdout")
         println("print")
     end
     flush(io)
     seek(io, 0)
-    @test read(io, String) == "print\n"
+    @test read(io, String) == "stdout\nprint\n"
     @test_throws ArgumentError redirect_stdout(IJulia.IJuliaStdio(io, "stderr"))
     @test_throws ArgumentError redirect_stdout(IJulia.IJuliaStdio(io, "stdin"))
     @test_throws ArgumentError redirect_stderr(IJulia.IJuliaStdio(io, "stdout"))
@@ -16,25 +19,20 @@ mktemp() do path, io
     @test_throws ArgumentError redirect_stdin(IJulia.IJuliaStdio(io, "stderr"))
 end
 
-# Helper function to strip out color codes from strings to make it easier to
-# compare output within tests that has been colorized
-function strip_colorization(s)
-    return replace(s, r"(\e\[\d+m)"m => "")
-end
-
 mktemp() do path, io
     redirect_stderr(IJulia.IJuliaStdio(io, "stderr")) do
-        warn("warn")
+        stderr = isdefined(Base, :devnull) ? Base.stderr : Base.STDERR
+        println(stderr, "stderr")
     end
     flush(io)
     seek(io, 0)
-    @test strip_colorization(read(io, String)) == "WARNING: warn\n"
+    @test read(io, String) == "stderr\n"
 end
 
 mktemp() do path, io
     redirect_stdin(IJulia.IJuliaStdio(io, "stdin")) do
         # We can't actually do anything here because `IJuliaexecute_msg` has not
-        # yet been initialized, so we just make sure that redirect_stdin does 
+        # yet been initialized, so we just make sure that redirect_stdin does
         # not error.
     end
 end