add tests for prompt timeout

Author: IanButterworth

test/misc.jl

@@ -516,6 +516,10 @@ let buf = IOBuffer()
     @test Base.prompt(IOBuffer("\n"), buf, "baz", default="foobar") == "foobar"
     @test String(take!(buf)) == "baz [foobar]: "
     @test Base.prompt(IOBuffer("blah\n"), buf, "baz", default="foobar") == "blah"
+
+    # prompt timeout
+    @test Base.prompt(devnull, buf, "baz", default="foobar", timeout = 1) == "foobar"
+    @test String(take!(buf)) == "baz [foobar] timeout 1 second: timed out"
 end
 
 # these tests are not in a test block so that they will compile separately