From b187d5064a7fda0e7aff433311077e7c3323f97b Mon Sep 17 00:00:00 2001
From: Greg Magolan <greg.magolan@robinhood.com>
Date: Thu, 16 Jul 2020 00:13:17 -0700
Subject: [PATCH] fix(builtin): linker fix for when not running in execroot

---
 internal/linker/index.js             |  6 ++++--
 internal/linker/link_node_modules.ts | 16 ++++++++++++++--
 internal/node/launcher.sh            |  6 ++++--
 3 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/internal/linker/index.js b/internal/linker/index.js
index 1500fe1230..0adba74cde 100644
--- a/internal/linker/index.js
+++ b/internal/linker/index.js
@@ -126,8 +126,10 @@ function resolveRoot(root, startCwd, isExecroot, runfiles) {
         }
         const match = startCwd.match(/(\/bazel-out\/|\/bazel-~1\/x64_wi~1\/)/);
         if (!match) {
-            panic(`No 'bazel-out' folder found in path '${startCwd}'!`);
-            return '';
+            if (!root) {
+                return `${startCwd}/node_modules`;
+            }
+            return path.resolve(`${startCwd}/../${root}`);
         }
         const symlinkRoot = startCwd.slice(0, match.index);
         process.chdir(symlinkRoot);
diff --git a/internal/linker/link_node_modules.ts b/internal/linker/link_node_modules.ts
index f196f8f668..e4e7f92f89 100644
--- a/internal/linker/link_node_modules.ts
+++ b/internal/linker/link_node_modules.ts
@@ -179,9 +179,21 @@ async function resolveRoot(
   // c:/b/ojvxx6nx/execroot/build_~1/bazel-~1/x64_wi~1/bin/internal/npm_in~1/test
   const match = startCwd.match(/(\/bazel-out\/|\/bazel-~1\/x64_wi~1\/)/);
   if (!match) {
-    panic(`No 'bazel-out' folder found in path '${startCwd}'!`);
-    return '';
+    // No execroot found. This can happen if we are inside a nodejs_image or a nodejs_binary is
+    // run manually.
+
+    if (!root) {
+      // If there is no root, which will be the case if there are no third-party modules
+      // dependencies for this target, simply link to node_modules at the cwd.
+      return `${startCwd}/node_modules`;
+    }
+
+    // If there is a root then attempt to symlink as if we are in runfiles in a sandbox. This will
+    // be the case for nodejs_image.
+    return path.resolve(`${startCwd}/../${root}`)
   }
+
+  // We've found the execroot
   const symlinkRoot = startCwd.slice(0, match.index);
   process.chdir(symlinkRoot);
 
diff --git a/internal/node/launcher.sh b/internal/node/launcher.sh
index 723486f563..4baa55ecac 100644
--- a/internal/node/launcher.sh
+++ b/internal/node/launcher.sh
@@ -276,9 +276,11 @@ if [[ "$PWD" == *"/bazel-out/"* ]]; then
   readonly execroot=${PWD:0:${index}}
   export BAZEL_PATCH_GUARDS="${execroot}/node_modules"
 else
-  # We are in execroot, linker node_modules is in the PWD
+  # We are in execroot or in some other context all together such as a nodejs_image or a manually
+  # run nodejs_binary. If this is execroot then linker node_modules is in the PWD. If this another
+  # context then it is safe to assume the node_modules are there and guard that directory if it exists.
   export BAZEL_PATCH_GUARDS="${PWD}/node_modules"
-fi 
+fi
 if [[ -n "${BAZEL_NODE_MODULES_ROOT:-}" ]]; then
   if [[ "${BAZEL_NODE_MODULES_ROOT}" != "${BAZEL_WORKSPACE}/node_modules" ]]; then
     # If BAZEL_NODE_MODULES_ROOT is set and it is not , add it to the list of bazel patch guards