[Lldb-commits] [PATCH] D37923: Implement interactive command interruption

[Jim Ingham via lldb-commits]

I'd really prefer to do this as/along with an SB API test since we also need commands made through the SB API to be interruptible, and we should test that that also works.  So this kills two birds with one stone.

In general, when developing any high-level features in lldb one of the questions you should ask yourself is whether this is useful at the SB API layer.  In this case it obviously is (actually I'm a little embarrassed I didn't think of this requirement).  If so, then it's simplest to test it at that layer.  If the SB API is anything more than a pass-through, then you might also want to write a unit test for the underlying C++ API's.  But in this case the SB function will just call the underlying CommandInterpreter one, so testing at the SB layer is sufficient.

Jim

> On Sep 19, 2017, at 10:45 AM, Zachary Turner via Phabricator <reviews at reviews.llvm.org> wrote:
> 
> zturner added a comment.
> 
> In https://reviews.llvm.org/D37923#875322, @clayborg wrote:
> 
>> We should have a test. The test would need to use pexpect or something similar. If anyone has any pointer on how to make a test for this, please chime in. I was thinking just a pexpect based test.
> 
> 
> This kind of thing is perfect for a unit test, but I'm not sure how easy that would be with the current design.  You'd basically do something like:
> 
>  struct MockStream {
>    explicit MockStream(CommandInterpreter &Interpreter, int InterruptAfter) 
>      : CommandInterpreter(Interpreter), InterruptAfter(InterruptAfter) {}
> 
>    CommandInterpreter &Interpreter;
>    const int InterruptAfter;
>    int Lines = 0;
>    std::string Buffer;
> 
>    void Write(StringRef S) {
>      ++Lines;
>      if (Lines >= InterruptAfter) {
>        Interpreter.Interrupt();
>        return;
>      }
>      Buffer += S;
>    }
>  };
> 
>  TEST_F(CommandInterruption) {
>    CommandInterpreter Interpreter;
>    MockStream Stream(Interpreter, 3);
>    Interpreter.PrintCommandOutput(Stream, "a\nb\nc\nd\ne\nf\n");
>    EXPECT_EQ(Stream.Lines == 3);
>    EXPECT_EQ(Stream.Buffer == "a\nb\nc\n");
>  }
> 
> 
> https://reviews.llvm.org/D37923
> 
> 
>