Deterministic output for testing

[Julian Hyde]

I am using JLine3 in my application and I am trying to write some tests to ensure that a given input produces a given output. For example, for input

  1 + 2;

my application should produce the output

  1 + 2;

  = 1 + 2;

  val it = 3 : int

(The line '= 1 + 2;' is expected because JLine re-displays the input with a  '= ' prompt.)

Unfortunately the output is non-deterministic. Sometimes the output is as follows:

  = 1 + 2;

  1 + 2;

  val it = 3 : int

I think this happens because the pump (a thread that copies from input to output) is running slower than usual.

Is this non-determinism expected? Is there any way to make the results deterministic? How do other people test applications that use JLine?

Julian

[Guillaume Nodet]

You can test using the same stuff that JLine actually use in its own tests.

See a test example at https://github.com/jline/jline3/blob/master/reader/src/test/java/org/jline/reader/impl/HistorySearchTest.java

--
You received this message because you are subscribed to the Google Groups "jline-users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to jline-users...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/jline-users/cf1761d5-9103-4828-b079-6986b99b91f0%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[Julian Hyde]

Thanks; I’ll give that a try.

By the way, I found a workaround which is to sleep for 10 milliseconds at the start of the test to wait for classes to load[1]. With that workaround tests seem to run consistently in practice.

Julian

[1] https://github.com/julianhyde/smlj/blob/f4eb212aa365f2fea818d3df69ca091f7b1d24aa/src/test/java/net/hydromatic/sml/ShellTest.java#L52

To view this discussion on the web visit https://groups.google.com/d/msgid/jline-users/CAEQV%2BEHuhf3ghh53sfHO1JNab_4hggcyhG%3DbvOUbGOok5x3DDQ%40mail.gmail.com.