ci: add bazel_integration_test (#338)

This runs a py_test with a copy of bazel as a data dep.
It glob()s up the sources for each example and runs nested bazel test on them.
This detects whether the examples are fully working and self-contained.

Follow-up step is to replace the rules_python.tgz with a HEAD version so we detect
breakages.

1 files changed, 17 insertions, 0 deletions

diff --git a/version.bzl b/version.bzl
index b9e2216..00d16b5 100644
--- a/version.bzl
+++ b/version.bzl
@@ -14,3 +14,20 @@
 """The version of rules_python."""
 
 version = "0.0.2"
+
+# Currently used Bazel version. This version is what the rules here are tested
+# against.
+# This version should be updated together with the version of the Bazel
+# in .bazelversion.
+# TODO(alexeagle): assert this is the case in a test
+BAZEL_VERSION = "3.3.1"
+
+# Versions of Bazel which users should be able to use.
+# Ensures we don't break backwards-compatibility,
+# accidentally forcing users to update their LTS-supported bazel.
+# These are the versions used when testing nested workspaces with
+# bazel_integration_test.
+SUPPORTED_BAZEL_VERSIONS = [
+    # TODO: add LTS versions of bazel like 1.0.0, 2.0.0
+    BAZEL_VERSION,
+]