fix: use quote-aware parser for NODE_OPTIONS and add argv overwrite justification

Address review feedback: replace naive whitespace splitting of NODE_OPTIONS
with a shell-like tokenizer that handles single/double quoted values
(e.g. --title="hello world"). Add comments explaining the argv buffer
overwrite technique with references to libuv/Node.js. Add spec tests
for process.title including quoted NODE_OPTIONS values.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: bartlomieju

ext/node/ops/process.rs

@@ -17,6 +17,16 @@ use nix::unistd::User;
 use crate::ExtNodeSys;
 
 // --- process.title support ---
+//
+// The argv buffer overwrite technique used here is the standard approach for
+// setting the process title visible in `ps`. This is the same technique used by
+// Node.js (via libuv's uv_setup_args/uv_set_process_title), nginx, PostgreSQL,
+// and many other programs. The OS allocates argv as a contiguous buffer; we
+// save its bounds at startup, then overwrite it with the new title.
+//
+// References:
+// - libuv: https://github.com/libuv/libuv/blob/v1.x/src/unix/proctitle.c
+// - Node.js: uses uv_setup_args() in node_main.cc, uv_set_process_title() in node.cc
 
 #[cfg(target_os = "linux")]
 mod argv_store {

ext/node/polyfills/internal_binding/node_options.ts

@@ -4,9 +4,8 @@ import { primordials } from "ext:core/mod.js";
 const {
   SafeMap,
   ArrayPrototypeForEach,
-  SafeRegExp,
+  ArrayPrototypePush,
   StringPrototypeSlice,
-  StringPrototypeSplit,
   StringPrototypeStartsWith,
 } = primordials;
 
@@ -15,6 +14,39 @@ const {
 // - https://github.com/nodejs/node/blob/master/src/node_options.cc
 // - https://github.com/nodejs/node/blob/master/src/node_options.h
 
+// Quote-aware tokenizer for NODE_OPTIONS. Node.js uses a shell-like parser
+// that respects single and double quotes, so `--title="hello world"` is a
+// single token whose value is `hello world`, not two tokens.
+function splitNodeOptions(input: string): string[] {
+  const args: string[] = [];
+  let current = "";
+  let inDouble = false;
+  let inSingle = false;
+
+  for (let i = 0; i < input.length; i++) {
+    const ch = input[i];
+    if (ch === '"' && !inSingle) {
+      inDouble = !inDouble;
+    } else if (ch === "'" && !inDouble) {
+      inSingle = !inSingle;
+    } else if (
+      (ch === " " || ch === "\t" || ch === "\n" || ch === "\r") && !inDouble &&
+      !inSingle
+    ) {
+      if (current.length > 0) {
+        ArrayPrototypePush(args, current);
+        current = "";
+      }
+    } else {
+      current += ch;
+    }
+  }
+  if (current.length > 0) {
+    ArrayPrototypePush(args, current);
+  }
+  return args;
+}
+
 /** Gets the all options for Node.js
  * This function is expensive to execute. `getOptionValue` in `internal/options.ts`
  * should be used instead to get a specific option. */
@@ -26,9 +58,7 @@ export function getOptions() {
   ]);
 
   const nodeOptions = Deno.env.get("NODE_OPTIONS");
-  const args = nodeOptions
-    ? StringPrototypeSplit(nodeOptions, new SafeRegExp("\\s"))
-    : [];
+  const args = nodeOptions ? splitNodeOptions(nodeOptions) : [];
   ArrayPrototypeForEach(args, (arg) => {
     if (StringPrototypeStartsWith(arg, "--title=")) {
       options.set("--title", { value: StringPrototypeSlice(arg, 8) });

tests/specs/node/process_title/__test__.jsonc

@@ -0,0 +1,26 @@
+{
+  "tests": {
+    "default_title_is_exec_path": {
+      "args": "run -A main.ts default",
+      "output": "default.out"
+    },
+    "set_title": {
+      "args": "run -A main.ts set",
+      "output": "set.out"
+    },
+    "node_options_title": {
+      "envs": {
+        "NODE_OPTIONS": "--title=custom-title"
+      },
+      "args": "run -A main.ts node_options",
+      "output": "node_options.out"
+    },
+    "node_options_title_quoted_spaces": {
+      "envs": {
+        "NODE_OPTIONS": "--title=\"hello world\""
+      },
+      "args": "run -A main.ts node_options",
+      "output": "node_options_quoted.out"
+    }
+  }
+}

tests/specs/node/process_title/default.out

@@ -0,0 +1 @@
+PASS

tests/specs/node/process_title/main.ts

@@ -0,0 +1,27 @@
+import process from "node:process";
+
+const mode = Deno.args[0];
+
+switch (mode) {
+  case "default":
+    // Default title should be the execPath
+    console.log(
+      process.title === process.execPath
+        ? "PASS"
+        : `FAIL: expected execPath, got ${process.title}`,
+    );
+    break;
+  case "set":
+    // Setting title should work
+    process.title = "my-custom-title";
+    console.log(
+      process.title === "my-custom-title"
+        ? "PASS"
+        : `FAIL: expected my-custom-title, got ${process.title}`,
+    );
+    break;
+  case "node_options":
+    // Title should come from NODE_OPTIONS --title=...
+    console.log(`title=${process.title}`);
+    break;
+}

tests/specs/node/process_title/node_options.out

@@ -0,0 +1 @@
+title=custom-title

tests/specs/node/process_title/node_options_quoted.out

@@ -0,0 +1 @@
+title=hello world

tests/specs/node/process_title/set.out

@@ -0,0 +1 @@
+PASS