Make the bazel rules work with current rules_closure.

[danfabi]

This commit introduced a helper function for creating closure_js_library.

[stanley-cheung]

@Yannic Please review, thanks!

[stanley-cheung]

There are test failures:

+ bazel test //javascript/net/grpc/web/... //net/grpc/gateway/examples/...
Starting local Bazel server and connecting to it...
...........................
Loading:
Loading: 0 packages loaded
Loading: 0 packages loaded
ERROR: /tmpfs/src/github/grpc-web/bazel/closure_grpc_web_library.bzl:5:1: file '@io_bazel_rules_closure//closure/compiler:closure_js_library.bzl' does not contain symbol 'create_closure_js_library'
ERROR: error loading package 'net/grpc/gateway/examples/echo': Extension file 'bazel/closure_grpc_web_library.bzl' has errors

[danfabi]

Forgot to update rules_closure in WORKSPACE. Tests should pass now.

[Yannic]

Thanks for the fix, (mostly) LGTM.

Could we remove _ClosureWorker and _closure_library_base from attrs and replace it with CLOSURE_JS_TOOLCHAIN_ATTRS like it's done in closure_js_library?
https://github.com/bazelbuild/rules_closure/blob/master/closure/compiler/closure_js_library.bzl#L431

[danfabi]

Done!

[Yannic]

LGTM

[stanley-cheung]

Sorry, still some test failures:

ERROR: /tmpfs/src/github/grpc-web/javascript/net/grpc/web/BUILD.bazel:148:1: in closure_js_binary rule //javascript/net/grpc/web:grpcwebstreamparser_test_bin:
Traceback (most recent call last):
	File "/tmpfs/src/github/grpc-web/javascript/net/grpc/web/BUILD.bazel", line 148
		closure_js_binary(name = 'grpcwebstreamparser_test_bin')
	File "/tmpfs/tmp/bazel/external/io_bazel_rules_closure/closure/compiler/closure_js_binary.bzl", line 212, in _impl
		all_args.add_all([src], map_each = get_jsfile_path, e...)
unexpected keyword 'expand_directories', in method call add_all(list, function map_each, bool expand_directories) of 'Args'
ERROR: Analysis of target '//javascript/net/grpc/web:grpcwebstreamparser_test' failed; build aborted: Analysis of target '//javascript/net/grpc/web:grpcwebstreamparser_test_bin' failed; build aborted

[Yannic]

Cannot reproduce this with Bazel 0.19.0. That failure looks like it's caused by a slightly outdated and therefore incompatible version of Bazel.
@stanley-cheung Can you check which version is installed on the kokoro runner, and update it if necessary?

[stanley-cheung]

Looks like the kokoro machine is having bazel version 0.15.0.

[Yannic]

Then it's clear why the tests fail. The expand_directories-argument was added to Bazel in 0.18.0.

There is more than one solution to resolve this:

• You could update Bazel on kokoro,
• We could modify the kokoro script to fetch the latest version of Bazel (maybe use bazelisk), or
• We could ask some working on Bazel CI to add this repository to their system. This would bring the advantage that grpc-web will be tested with the latest version automatically (@buchgr, @damienmg, @philwo).

[stanley-cheung]

#373 should help.

[Yannic]

@factuno-db We think that #373 will fix the failing tests. Please rebase when the other PR is merged so we can run the tests again, thanks!

[danfabi]

Yeah, I saw it. Thanks for taking care of this!

[stanley-cheung]

@factuno-db #373 is merged. Please rebase so we can run the tests again. Thanks!

[danfabi]

Done!

[stanley-cheung]

Thanks for the contributions!