Remove use of proto_library.proto_source_root

[aaliddell]

This attribute is destined to be removed in Bazel 1.0: bazelbuild/bazel#7153

The test workspace for this attribute can then also be removed.

[lberki]

Note that the functionality of stripping prefixes from proto import paths will still be there, it's just that the attribute was replaced with strip_import_prefix / import_prefix so that prefixes can also be added and so that it's more coherent with our C++ rules..

[aaliddell]

Ah, so does the proto_source_root property on the ProtoInfo provider remain then?

Those other two new attributes are presently supported and strip_import_prefix is tested here (although may need the '/' adding). A test workspace could be added for import_prefix though.

[lberki]

Yep, the dep[ProtoInfo].proto_source_root is going to stay, it's just proto_library.proto_source_root that's going away.

[aaliddell]

Ok, thanks. I've restored the use of the provider property and added a bunch more test workspaces on the branch for various combinations of those attributes. However, whilst doing so I came across an issue with duplicate files appearing in ProtoInfo.direct_sources when using import_prefix: bazelbuild/bazel#9127

[lberki]

Commented on the bug. TL;DR: that will be fixed in Bazel 1.0 as an excellent example of acausal development (We fix bugs even before you report them!)

In the meantime, can you live with the duplication?

[aaliddell]

Serendipity! It's fine as-is, I've put in a check to skip duplicates in that list.