Merge branch 'stable-2.15' into stable-2.16

* stable-2.15:
  run_test.sh: Fix bazelisk location detection
  Bazel: Adapt docs for custom plugins with external deps
  PolyGerrit: Run WCT tests using bazelisk

Change-Id: I9c98b28cc467ea805b677808e40393ffb4572c1a

Documentation/dev-build-plugins.txt

@@ -122,16 +122,25 @@ CUSTOM_PLUGINS_TEST_DEPS = [
 ----
 
 If the plugin(s) being bundled in the release have external dependencies, include them
-in `plugins/external_plugin_deps`. You should alias `external_plugin_deps()` so it
-can be imported for multiple plugins. For example:
+in `plugins/external_plugin_deps`. Create symbolic link from plugin's own
+`external_plugin_deps()` file in plugins directory and prefix the file with
+plugin name, e.g.:
 
 ----
-load(":my-plugin/external_plugin_deps.bzl", my_plugin="external_plugin_deps")
-load(":my-other-plugin/external_plugin_deps.bzl", my_other_plugin="external_plugin_deps")
+  $ cd plugins
+  $ ln -s oauth/external_plugin_deps.bzl oauth_external_plugin_deps.bzl
+  $ ln -s uploadvalidator/external_plugin_deps.bzl uploadvalidator_external_plugin_deps.bzl
+----
+
+Now the plugin specific dependency files can be imported:
+
+----
+load(":oauth_external_plugin_deps.bzl", oauth_deps="external_plugin_deps")
+load(":uploadvalidator_external_plugin_deps.bzl", uploadvalidator_deps="external_plugin_deps")
 
 def external_plugin_deps():
-  my_plugin()
-  my_other_plugin()
+  oauth_deps()
+  uploadvalidator_deps()
 ----
 
 [NOTE]

polygerrit-ui/app/run_test.sh

@@ -12,9 +12,15 @@ if [[ -z "$wct_bin" ]]; then
     exit 1
 fi
 
+bazel_bin=$(which bazelisk 2>/dev/null)
+if [[ -z "$bazel_bin" ]]; then
+    echo "Warning: bazelisk is not installed; falling back to bazel."
+    bazel_bin=bazel
+fi
+
 # WCT tests are not hermetic, and need extra environment variables.
 # TODO(hanwen): does $DISPLAY even work on OSX?
-bazel test \
+${bazel_bin} test \
       --test_env="HOME=$HOME" \
       --test_env="WCT=${wct_bin}" \
       --test_env="WCT_ARGS=${WCT_ARGS}" \