Add a global --tag option to filter targets based on their tags.
Review Request #2362 - Created June 13, 2015 and submitted
--tag=foo,bar includes only targets that have at least one of those tags. --tag=-foo,bar includes only targets that have none of those tags. --tag=foo,bar --tag=-baz includes only targets that have at least one of the tags foo or bar, and do not have the tag baz. The filtering is on target roots, of course, similar to spec_excludes and exclude_target_regexp. Dependencies are included in the targets passed to Task.execute() regardless of their tags. We already had similar filtering functionality in the Filter task. So I refactored some of that into a new filtering.py file under util. While doing so, I noticed that the help text on Filter's options was wrong: In --tag=-foo,bar the '-' prefix applies to both foo and bar, and --tag=-foo,+bar is not sensible. While fixing up the help strings I realized that it would be more succinct to move the common help text (the part explaining about the prefix and how multiple filters are specified) into the goal description. Then I realized that it would be pretty verbose to put that in the with_description() text in register.py, so I added a little thing that uses the task's docstring as the description, if one isn't provided explicitly. Note that Filter still has its own --tag option, which we can think about deprecating in a future change. IMPORTANT: While testing, I noticed that we had a longstanding bug, where multiple filters of the same type wouldn't work, because in the loop the filter() function was capturing the same references in its closure on each iteration. See the test I added in test_filter.py - that test fails with no other changes at HEAD. Also note that the test marked as xfail is behaving as intended: according to the implementation, separate specifications of the same option are ANDed (while comma-separated values in a single specification are ORed). If we want the behavior to be different then we can discuss, but for now at least that xfail was inappropriate and misleading.
CI passes: https://travis-ci.org/pantsbuild/pants/builds/66695055
Agreed, but goals needs some work to accomodate this better going forward:
pants.dev goals ... filemap: Outputs a mapping from source file to owning target. filter: Filter the input targets based on various criteria. Each of the filtering options below is a comma-separated list of filtering criteria, with an implied logical OR between them, so that a target passes the filter if it matches any of the criteria in the list. A '-' prefix inverts the sense of the entire comma-separated list, so that a target passes the filter only if it matches none of the criteria in the list. Each of the filtering options may be specified multiple times, with an implied logical AND between them. gen: Generate code. goals: List all documented goals. ...
Perhaps the 1st sentence for goals output and the full doc for
I'd prefer an issue or TODO over action in this RB.
Status: Closed (submitted)
Submitted as 6c1ac098535f453af47656cf132a047724c2de5c.