windows: runfiles resolution must handle both manifest and symlink ca…

…ses (#20)

see bazelbuild/bazel#3726

internal/node_launcher.sh

@@ -16,25 +16,25 @@
 set -e
 
 # Launcher for NodeJS applications.
-# Find our runfiles manifest. We need this to launch node with the correct
+# Find our runfiles. We need this to launch node with the correct
 # entry point.
 #
 # Call this program X. X was generated by a genrule and may be invoked
 # in many ways:
 #   1a) directly by a user, with $0 in the output tree
 #   1b) via 'bazel run' (similar to case 1a)
-#   2) directly by a user, with $0 in X's runfiles manifest
+#   2) directly by a user, with $0 in X's runfiles
 #   3) by another program Y which has a data dependency on X, with $0 in Y's
-#      runfiles manifest
+#      runfiles
 #   4a) via 'bazel test'
 #   4b) case 3 in the context of a test
 #   5a) by a genrule cmd, with $0 in the output tree
 #   6a) case 3 in the context of a genrule
 #
-# For case 1, $0 will be a regular file, and the runfiles manifest will be
+# For case 1, $0 will be a regular file, and the runfiles will be
 # at $0.runfiles.
 # For case 2 or 3, $0 will be a symlink to the file seen in case 1.
-# For case 4, $TEST_SRCDIR should already be set to the runfiles manifest by
+# For case 4, $TEST_SRCDIR should already be set to the runfiles by
 # blaze.
 # Case 5a is handled like case 1.
 # Case 6a is handled like case 3.
@@ -46,16 +46,16 @@ esac
 
 if [[ -n "$TEST_SRCDIR" ]]; then
   # Case 4, bazel has identified runfiles for us.
-  RUNFILES="${TEST_SRCDIR}_manifest"
+  RUNFILES="${TEST_SRCDIR}"
 else
   while true; do
     if [[ -e "$self.runfiles" ]]; then
-      RUNFILES="$self.runfiles_manifest"
+      RUNFILES="$self.runfiles"
       break
     fi
 
     if [[ $self == *.runfiles/* ]]; then
-      RUNFILES="${self%%.runfiles/*}.runfiles_manifest"
+      RUNFILES="${self%%.runfiles/*}.runfiles"
       # don't break; this is a last resort for case 6b
     fi
 
@@ -92,21 +92,31 @@ done
 # Note: for debugging it is useful to see what files are actually present, eg:
 # find . -name thingImLookingFor
 
-# Lookup the real paths from the runfiles manifest with no dependency on posix
-while read line; do
-  declare -a PARTS=($line)
-  if [ "${PARTS[0]}" == "TEMPLATED_node" ]; then
-    readonly node="${PARTS[1]}"
-  elif [ "${PARTS[0]}" == "TEMPLATED_script_path" ]; then
-    readonly script="${PARTS[1]}"
+# On Windows, the runfiles symlink tree does not exist, so we must resolve paths
+# using the mapping in the runfiles_manifest file.
+# See https://github.com/bazelbuild/bazel/issues/3726
+readonly MANIFEST="${RUNFILES}_manifest"
+if [ -e "${MANIFEST}" ]; then
+  # Lookup the real paths from the runfiles manifest with no dependency on posix
+  while read line; do
+    declare -a PARTS=($line)
+    if [ "${PARTS[0]}" == "TEMPLATED_node" ]; then
+      readonly node="${PARTS[1]}"
+    elif [ "${PARTS[0]}" == "TEMPLATED_script_path" ]; then
+      readonly script="${PARTS[1]}"
+    fi
+  done < ${MANIFEST}
+  if [ -z "${node}" ]; then
+    echo "Failed to find node binary TEMPLATED_node in manifest ${MANIFEST}"
+    exit 1
   fi
-done < ${RUNFILES}
-if [ -z "${node}" ]; then
-  echo "Failed to find node binary TEMPLATED_node in manifest ${RUNFILES}"
-  exit 1
-fi
-if [ -z "${script}" ]; then
-  echo "Failed to find script TEMPLATED_script_path in manifest ${RUNFILES}"
-  exit 1
+  if [ -z "${script}" ]; then
+    echo "Failed to find script TEMPLATED_script_path in manifest ${MANIFEST}"
+    exit 1
+  fi
+else
+  readonly node="${RUNFILES}/TEMPLATED_node"
+  readonly script="${RUNFILES}/TEMPLATED_script_path"
 fi
+
 exec "${node}" "${NODE_OPTIONS[@]}" "${script}" "${ARGS[@]}"

internal/node_loader.js

@@ -61,8 +61,15 @@ function resolveToModuleRoot(path) {
  * The runfiles manifest maps from short_path
  * https://docs.bazel.build/versions/master/skylark/lib/File.html#short_path
  * to the actual location on disk where the file can be read.
+ *
+ * In a sandboxed execution, it does not exist. In that case, runfiles must be
+ * resolved from a symlink tree under the runfiles dir.
+ * See https://github.com/bazelbuild/bazel/issues/3726
  */
 function loadRunfilesManifest(manifestPath) {
+  if (!fs.existsSync(manifestPath)) {
+    return;
+  }
   const result = Object.create(null);
   const input = fs.readFileSync(manifestPath, {encoding: 'utf-8'});
   for (const line of input.split("\n")) {
@@ -72,20 +79,28 @@ function loadRunfilesManifest(manifestPath) {
   }
   return result;
 }
-const runfilesManifest = loadRunfilesManifest(process.env.RUNFILES);
+const runfilesManifest = loadRunfilesManifest(`${process.env.RUNFILES}_manifest`);
+
+function resolveRunfiles(...pathSegments) {
+  if (runfilesManifest) {
+    // Join on forward slash, because even on Windows the runfiles_manifest
+    // file is written with forward slash.
+    return runfilesManifest[pathSegments.join('/')];
+  } else {
+    return path.join(process.env.RUNFILES, ...pathSegments);
+  }
+}
 
 var originalResolveFilename = module.constructor._resolveFilename;
 module.constructor._resolveFilename =
     function(request, parent) {
   var failedResolutions = [];
   var resolveLocations = [
     request,
-    runfilesManifest[request],
-    // Join on forward slash, because even on Windows the runfiles_manifest
-    // file is written with forward slash.
-    runfilesManifest[[
+    resolveRunfiles(request),
+    resolveRunfiles(
       'TEMPLATED_workspace_name', 'TEMPLATED_label_package',
-      'node_modules', request].join('/')],
+      'node_modules', request),
   ];
   for (var location of resolveLocations) {
     try {