Add standalone bazel build

Change-Id: I16cef3f3b0f83ac5272903fb83c0a394f8091b6a
diff --git a/.gitignore b/.gitignore
index d781c5f..cb092fe 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,9 +1,11 @@
 /.buckd
 /.buckversion
 /.classpath
+/.primary_build_tool
 /.project
 /.settings/
 /.watchmanconfig
+/bazel-*
 /buck-out
 /bucklets
 /eclipse-out/
diff --git a/BUILD b/BUILD
index dcf1f80..41af36e 100644
--- a/BUILD
+++ b/BUILD
@@ -23,7 +23,16 @@
     name = "project_group_structure_tests",
     srcs = glob(["src/test/java/**/*.java"]),
     tags = ["project-group-structure"],
-    deps = PLUGIN_DEPS + PLUGIN_TEST_DEPS + [
+    deps = [
+        ":project-group-structure__plugin_test_deps",
+    ],
+)
+
+java_library(
+    name = "project-group-structure__plugin_test_deps",
+    testonly = 1,
+    visibility = ["//visibility:public"],
+    exports = PLUGIN_DEPS + PLUGIN_TEST_DEPS + [
         ":project-group-structure__plugin",
     ],
 )
diff --git a/WORKSPACE b/WORKSPACE
new file mode 100644
index 0000000..0e40278
--- /dev/null
+++ b/WORKSPACE
@@ -0,0 +1,25 @@
+workspace(name = "project_group_structure")
+load("//:bazlets.bzl", "load_bazlets")
+
+load_bazlets(
+    commit = "e50890188cd63f79d4a8529f90024f56168f9c9a",
+    #    local_path = "/home/<user>/projects/bazlets",
+)
+
+#Snapshot Plugin API
+#load(
+#    "@com_googlesource_gerrit_bazlets//:gerrit_api_maven_local.bzl",
+#    "gerrit_api_maven_local",
+#)
+
+# Load snapshot Plugin API
+#gerrit_api_maven_local()
+
+# Release Plugin API
+load(
+   "@com_googlesource_gerrit_bazlets//:gerrit_api.bzl",
+   "gerrit_api",
+)
+
+# Load release Plugin API
+gerrit_api()
diff --git a/bazlets.bzl b/bazlets.bzl
new file mode 100644
index 0000000..e14e488
--- /dev/null
+++ b/bazlets.bzl
@@ -0,0 +1,17 @@
+NAME = "com_googlesource_gerrit_bazlets"
+
+def load_bazlets(
+    commit,
+    local_path = None
+  ):
+  if not local_path:
+      native.git_repository(
+          name = NAME,
+          remote = "https://gerrit.googlesource.com/bazlets",
+          commit = commit,
+      )
+  else:
+      native.local_repository(
+          name = NAME,
+          path = local_path,
+      )
diff --git a/src/main/resources/Documentation/build.md b/src/main/resources/Documentation/build.md
index 935077b..630c6fb 100644
--- a/src/main/resources/Documentation/build.md
+++ b/src/main/resources/Documentation/build.md
@@ -1,17 +1,69 @@
-Build
-=====
+# Build
 
-This @PLUGIN@ plugin is built with Bazel.
+This plugin can be built with Bazel, and two build modes are supported:
 
-Clone (or link) this plugin to the `plugins` directory of Gerrit's source tree.
+* Standalone
+* In Gerrit tree
 
-Then issue
+Standalone build mode is recommended, as this mode doesn't require local Gerrit
+tree to exist. Moreover, there are some limitations and additional manual steps
+required when building in Gerrit tree mode (see corresponding sections).
+
+## Build standalone
+
+To build the plugin, issue the following command:
+
+```
+  bazel build @PLUGIN@
+```
+
+The output is created in
+
+```
+  bazel-genfiles/@PLUGIN@.jar
+```
+
+To package the plugin sources run:
+
+```
+  bazel build lib@PLUGIN@__plugin-src.jar
+```
+
+The output is created in:
+
+```
+  bazel-bin/lib@PLUGIN@__plugin-src.jar
+```
+
+To execute the tests run:
+
+```
+  bazel test //...
+```
+
+This project can be imported into the Eclipse IDE:
+
+```
+  ./tools/eclipse/project.sh
+```
+
+## Build in Gerrit tree
+
+Clone or link this plugin to the plugins directory of Gerrit's
+source tree. From Gerrit source tree issue the command:
 
 ```
   bazel build plugins/@PLUGIN@
 ```
 
-in the root of Gerrit's source tree to build
+Note that due to a [known issue in Bazel][bazelissue], if the plugin
+has previously been built in standalone mode, it is necessary to clean
+the workspace before building in-tree:
+
+```
+  cd plugins/@PLUGIN@
+  bazel clean --expunge
+```
 
 The output is created in
 
@@ -19,9 +71,9 @@
   bazel-genfiles/plugins/@PLUGIN@/@PLUGIN@.jar
 ```
 
-This project can be imported into the Eclipse IDE.
-Add the plugin name to the `CUSTOM_PLUGINS` set in
-Gerrit core in `tools/bzl/plugins.bzl`, and execute:
+This project can be imported into the Eclipse IDE:
+Add the plugin name to the `CUSTOM_PLUGINS` in `tools/bzl/plugins.bzl`, and
+execute:
 
 ```
   ./tools/eclipse/project.py
@@ -30,5 +82,11 @@
 To execute the tests run:
 
 ```
-  bazel test plugins/@PLUGIN@:project_group_structure_tests
+  bazel test --test_tag_filters=@PLUGIN@ //...
 ```
+
+
+[Back to @PLUGIN@ documentation index][index]
+
+[index]: index.html
+[bazelissue]: https://github.com/bazelbuild/bazel/issues/2797
diff --git a/tools/bazel.rc b/tools/bazel.rc
new file mode 100644
index 0000000..4ed16cf
--- /dev/null
+++ b/tools/bazel.rc
@@ -0,0 +1,2 @@
+build --workspace_status_command=./tools/workspace-status.sh
+test --build_tests_only
diff --git a/tools/bzl/BUILD b/tools/bzl/BUILD
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/tools/bzl/BUILD
diff --git a/tools/bzl/classpath.bzl b/tools/bzl/classpath.bzl
new file mode 100644
index 0000000..dfcbe9c
--- /dev/null
+++ b/tools/bzl/classpath.bzl
@@ -0,0 +1,2 @@
+load("@com_googlesource_gerrit_bazlets//tools:classpath.bzl",
+     "classpath_collector")
diff --git a/tools/bzl/junit.bzl b/tools/bzl/junit.bzl
new file mode 100644
index 0000000..3af7e58
--- /dev/null
+++ b/tools/bzl/junit.bzl
@@ -0,0 +1,4 @@
+load(
+    "@com_googlesource_gerrit_bazlets//tools:junit.bzl",
+    "junit_tests",
+)
diff --git a/tools/bzl/plugin.bzl b/tools/bzl/plugin.bzl
new file mode 100644
index 0000000..a2e438f
--- /dev/null
+++ b/tools/bzl/plugin.bzl
@@ -0,0 +1,6 @@
+load(
+    "@com_googlesource_gerrit_bazlets//:gerrit_plugin.bzl",
+    "gerrit_plugin",
+    "PLUGIN_DEPS",
+    "PLUGIN_TEST_DEPS",
+)
diff --git a/tools/eclipse/BUILD b/tools/eclipse/BUILD
new file mode 100644
index 0000000..1691f5d
--- /dev/null
+++ b/tools/eclipse/BUILD
@@ -0,0 +1,17 @@
+load("//tools/bzl:classpath.bzl", "classpath_collector")
+
+java_library(
+    name = "classpath",
+    testonly = 1,
+    runtime_deps = [
+        "//:project-group-structure__plugin_test_deps",
+    ],
+)
+
+classpath_collector(
+    name = "main_classpath_collect",
+    testonly = 1,
+    deps = [
+        "//:project-group-structure__plugin_test_deps",
+    ],
+)
diff --git a/tools/eclipse/project.sh b/tools/eclipse/project.sh
new file mode 100755
index 0000000..be0fd7a
--- /dev/null
+++ b/tools/eclipse/project.sh
@@ -0,0 +1,15 @@
+#!/bin/bash
+# Copyright (C) 2017 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+`bazel query @com_googlesource_gerrit_bazlets//tools/eclipse:project --output location | sed s/BUILD:.*//`project.py -n project-group-structure -r .
diff --git a/tools/workspace-status.sh b/tools/workspace-status.sh
new file mode 100755
index 0000000..5320776
--- /dev/null
+++ b/tools/workspace-status.sh
@@ -0,0 +1,17 @@
+#!/bin/bash
+
+# This script will be run by bazel when the build process starts to
+# generate key-value information that represents the status of the
+# workspace. The output should be like
+#
+# KEY1 VALUE1
+# KEY2 VALUE2
+#
+# If the script exits with non-zero code, it's considered as a failure
+# and the output will be discarded.
+
+function rev() {
+  cd $1; git describe --always --match "v[0-9].*" --dirty
+}
+
+echo STABLE_BUILD_PROJECT-GROUP-STRUCTURE_LABEL $(rev .)