build: use cross platform workspace_status_command

.bazelrc

@@ -35,7 +35,9 @@ test --nolegacy_external_runfiles
 ###############################
 
 # Releases should always be stamped with version control info
-build:release --workspace_status_command=./tools/bazel_stamp_vars.sh
+# This command assumes node on the path and is a workaround for
+# https://github.com/bazelbuild/bazel/issues/4802
+build:release --workspace_status_command="node ./tools/bazel_stamp_vars.js"
 
 ###############################
 # Output                      #

docs/BAZEL.md

@@ -149,7 +149,7 @@ Bazel supports the ability to include non-hermetic information from the version
 You can see an overview at https://www.kchodorow.com/blog/2017/03/27/stamping-your-builds/
 In our repo, here is how it's configured:
 
-1) In `tools/bazel_stamp_vars.sh` we run the `git` commands to generate our versioning info.
+1) In `tools/bazel_stamp_vars.js` we run the `git` commands to generate our versioning info.
 1) In `.bazelrc` we register this script as the value for the `workspace_status_command` flag. Bazel will run the script when it needs to stamp a binary.
 
 Note that Bazel has a `--stamp` argument to `yarn bazel build`, but this has no effect since our stamping takes place in Skylark rules. See https://github.com/bazelbuild/bazel/issues/1054

tools/bazel_stamp_vars.js

@@ -0,0 +1,56 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+// tslint:disable:no-console
+// Generates the data used by the stamping feature in bazel.
+// See the section on stamping in docs / BAZEL.md
+// This script must be a NodeJS script in order to be cross-platform.
+// See https://github.com/bazelbuild/bazel/issues/5958
+// Note: git operations, especially git status, take a long time inside mounted docker volumes
+// in Windows or OSX hosts (https://github.com/docker/for-win/issues/188).
+const execSync = require('child_process').execSync;
+function _exec(str) {
+  return execSync(str).toString().trim();
+}
+
+console.error('Running', process.argv.join(' '));
+
+function onError() {
+  console.log('Failed to execute:,', process.argv.join(' '));
+  console.log('');
+}
+
+// Setup crash handler
+process.on('uncaughtException', onError);
+
+const BUILD_SCM_HASH = _exec(`git rev-parse HEAD`);
+console.log(`BUILD_SCM_HASH ${BUILD_SCM_HASH}`);
+
+if (_exec(`git tag`) == '') {
+  console.error(`No git tags found, can't stamp the build.`);
+  console.error('Please fetch the tags first:');
+  console.error('       git fetch git@github.com:angular/angular.git --tags');
+}
+
+// Find out if there are any uncommitted local changes
+const LOCAL_CHANGES = _exec(`git status --untracked-files=no --porcelain`) != '';
+console.log(`BUILD_SCM_LOCAL_CHANGES ${LOCAL_CHANGES}`);
+
+// Only match the latest tag that is a version such as 6.0.0, 6.0.0-rc.5, etc...
+// This will ignore non-version tags which would break unit tests expecting a valid version
+// number in the package headers
+const BUILD_SCM_VERSION_RAW =
+    _exec(`git describe --match [0-9].[0-9].[0-9]* --abbrev=7 --tags HEAD`);
+
+// Reformat `git describe` version string into a more semver-ish string
+//   From:   5.2.0-rc.0-57-g757f886
+//   To:     5.2.0-rc.0+57.sha-757f886
+//   Or:     5.2.0-rc.0+57.sha-757f886.with-local-changes
+const BUILD_SCM_VERSION = BUILD_SCM_VERSION_RAW.replace(/-([0-9]+)-g/, '+$1.sha-') +
+    (LOCAL_CHANGES ? '.with-local-changes' : '');
+console.log(`BUILD_SCM_VERSION ${BUILD_SCM_VERSION}`);