src: create task runner PATH when missing

Track whether the inherited environment contains PATH and create it from
the discovered node_modules/.bin paths when absent.

Signed-off-by: Archkon <180910180+Archkon@users.noreply.github.com>

Author: Archkon

src/node_task_runner.cc

@@ -93,6 +93,8 @@ void ProcessRunner::SetEnvironmentVariables() {
   int env_count;
   CHECK_EQ(0, uv_os_environ(&env_items, &env_count));
 
+  bool has_path_env_var = false;
+
   // Iterate over environment variables once to store them in the current
   // ProcessRunner instance.
   for (int i = 0; i < env_count; i++) {
@@ -110,12 +112,17 @@ void ProcessRunner::SetEnvironmentVariables() {
 
     if (StringEqualNoCase(name.c_str(), "path")) {
       // Add path env variable to the beginning of the PATH
+      has_path_env_var = true;
       value = path_env_var_ + value;
     }
     env_vars_.push_back(name + "=" + value);
   }
   uv_os_free_environ(env_items, env_count);
 
+  if (!has_path_env_var) {
+    env_vars_.push_back("PATH=" + path_env_var_);
+  }
+
   // Add NODE_RUN_SCRIPT_NAME environment variable to the environment
   // to indicate which script is being run.
   env_vars_.push_back("NODE_RUN_SCRIPT_NAME=" + script_name_);

test/parallel/test-node-run.js

@@ -45,6 +45,21 @@ describe('node --run [command]', () => {
     assert.strictEqual(child.code, 0);
   });
 
+  it('creates PATH when it is missing from the environment', async () => {
+    const env = Object.fromEntries(
+      Object.entries(process.env)
+        .filter(([key]) => key.toLowerCase() !== 'path'),
+    );
+    const child = await common.spawnPromisified(
+      process.execPath,
+      [ '--run', `ada${envSuffix}`],
+      { cwd: fixtures.path('run-script'), env },
+    );
+    assert.match(child.stdout, /06062023/);
+    assert.strictEqual(child.stderr, '');
+    assert.strictEqual(child.code, 0);
+  });
+
   it('chdirs into package directory', async () => {
     const child = await common.spawnPromisified(
       process.execPath,