copy_file: add rule and tests (#123)

This PR adds two new rules: copy_file and
copy_xfile.

Both rules solve a common problem: to copy one
file to another location. The problem is routinely
solved using a genrule. That however requires
Bash, since genrules execute Bash commands.
Requiring Bash is a problem on Windows.

The new rules do not require Bash on Windows (only
on other platforms).

The only difference between the rules is that
copy_xfile creates an executable file while
copy_file doesn't.

See https://github.com/bazelbuild/bazel/issues/4319

1 files changed, 7 insertions, 0 deletions

diff --git a/docs/BUILD b/docs/BUILD
index 3bf6a3c..76486aa 100644
--- a/docs/BUILD
+++ b/docs/BUILD
@@ -93,6 +93,13 @@ stardoc(
 )
 
 stardoc(
+    name = "copy_file_docs",
+    out = "copy_file_doc_gen.md",
+    input = "//rules:copy_file.bzl",
+    deps = ["//rules:copy_file"],
+)
+
+stardoc(
     name = "maprule_docs",
     out = "maprule_doc_gen.md",
     input = "//rules:maprule.bzl",