TracePoint for :line never seems to trigger on argument list. Maybe by design?
I have the following code.
30 1| def print_summary( 31 0| output = $stdout 32 | )
In the margin is the line number followed by the number of hits according to
:line trace point.
I feel like line 31 should also trigger a line trace point. It's an argument, but it must be executed.
Maybe a different trace point?
Updated by mame (Yusuke Endoh) about 3 years ago
I'm unsure about your assumption. If you can insert a newline freely, you may want to write the following code:
30 1| def print_summary( 31 | output = ( 32 0| $stdout 33 | ) 34 | )
You can hook Line 32 as a
We usually write an optional argument in a line:
def print_summary(out = $stdout). I don't think it is a good idea to deal with such a code as a
:line event because for
def foo(x = 1, y = 2) we cannot distinguish
x event and
As you say, if we really need this, we should add a new event type like
:argument, but we need to design its API carefully based on actual use cases.
Updated by shevegen (Robert A. Heiler) about 3 years ago
I don't have anything overly helpful to the discussion to add; but I wanted
to add one thing to this:
We usually write an optional argument in a line: def print_summary(out = $stdout)
While I concur in general, I myself have experimented a little with layout
def foo( a = 'foo', b = 'bar', )
The reason was primarily because it is, for my bad eyesight, easier to assess which
arguments are used; I only have to look at the left hand side mostly. Makes it easier
for me to keep track what is going on.
This may be a rare layout perhaps, but coming from this, I understand where Samuel
is coming from (but this is not me saying anything pro or con on the suggestion
itself; I really only wanted to comment on spaced-out optional arguments).
On a side note that may not be very relevant either, one can add strings to ')'
def foo( i = 'bar' )"hello world!" puts i end foo
I don't even know if that is a bug or a feature or something totally irrelevant.
I just found it funny and golfing-worthy (even though I am a horrible code golfer).
Almost a bit like python doc strings! :D
Updated by jeremyevans0 (Jeremy Evans) 3 months ago
This is basically the same issue as #15634. The default argument evaluation is not considered a separate expression, so no line event is generated. If you force it to use a separate expression by wrapping in parentheses, you can get a line event, as mame (Yusuke Endoh) demonstrated.
Note that when not using a separate expression, the
coverage shows a nil for the line. If you force a separate expression and line, the
coverage library can tell if the line was covered or not.