wasi: make returnOnExit true by default

doc/api/wasi.md

@@ -121,6 +121,9 @@ changes:
  - version: REPLACEME
    pr-url: https://github.com/nodejs/node/pull/47391
    description: The version option is now required and has no default value.
+ - version: REPLACEME
+   pr-url: https://github.com/nodejs/node/pull/47390
+   description: default value of returnOnExit changed to true.
  - version: v19.8.0
    pr-url: https://github.com/nodejs/node/pull/46469
    description: version field added to options.
@@ -136,10 +139,11 @@ changes:
     sandbox directory structure. The string keys of `preopens` are treated as
     directories within the sandbox. The corresponding values in `preopens` are
     the real paths to those directories on the host machine.
-  * `returnOnExit` {boolean} By default, WASI applications terminate the Node.js
-    process via the `__wasi_proc_exit()` function. Setting this option to `true`
-    causes `wasi.start()` to return the exit code rather than terminate the
-    process. **Default:** `false`.
+  * `returnOnExit` {boolean} By default, when WASI applications call
+    `__wasi_proc_exit()`  `wasi.start()` will return with the exit code
+    specified rather than terminatng the process. Setting this option to
+    `false` will cause the Node.js process to exit with the specified
+    exit code instead.  **Default:** `true`.
   * `stdin` {integer} The file descriptor used as standard input in the
     WebAssembly application. **Default:** `0`.
   * `stdout` {integer} The file descriptor used as standard output in the

lib/wasi.js

@@ -102,11 +102,13 @@ class WASI {
       wrap[prop] = FunctionPrototypeBind(wrap[prop], wrap);
     }
 
+    let returnOnExit = true;
     if (options.returnOnExit !== undefined) {
       validateBoolean(options.returnOnExit, 'options.returnOnExit');
-      if (options.returnOnExit)
-        wrap.proc_exit = FunctionPrototypeBind(wasiReturnOnProcExit, this);
+      returnOnExit = options.returnOnExit;
     }
+    if (returnOnExit)
+      wrap.proc_exit = FunctionPrototypeBind(wasiReturnOnProcExit, this);
 
     this[kSetMemory] = wrap._setMemory;
     delete wrap._setMemory;

test/wasi/test-wasi.js

@@ -1,6 +1,15 @@
 'use strict';
 const common = require('../common');
 
+function returnOnExitEnvToValue(env) {
+  const envValue = env.RETURN_ON_EXIT;
+  if (envValue === undefined) {
+    return undefined;
+  }
+
+  return envValue === 'true';
+}
+
 if (process.argv[2] === 'wasi-child-preview1') {
   // Test version set to preview1
   const assert = require('assert');
@@ -23,6 +32,7 @@ if (process.argv[2] === 'wasi-child-preview1') {
       '/sandbox': fixtures.path('wasi'),
       '/tmp': tmpdir.path,
     },
+    returnOnExit: returnOnExitEnvToValue(process.env),
   });
 
   // Validate the getImportObject helper
@@ -56,6 +66,10 @@ if (process.argv[2] === 'wasi-child-preview1') {
     if (options.stdin !== undefined)
       opts.input = options.stdin;
 
+    if ('returnOnExit' in options) {
+      opts.env.RETURN_ON_EXIT = options.returnOnExit;
+    }
+
     const child = cp.spawnSync(process.execPath, [
       ...args,
       __filename,
@@ -79,7 +93,9 @@ if (process.argv[2] === 'wasi-child-preview1') {
   if (!common.isIBMi) {
     runWASI({ test: 'clock_getres' });
   }
-  runWASI({ test: 'exitcode', exitCode: 120 });
+  runWASI({ test: 'exitcode' });
+  runWASI({ test: 'exitcode', returnOnExit: true });
+  runWASI({ test: 'exitcode', exitCode: 120, returnOnExit: false });
   runWASI({ test: 'fd_prestat_get_refresh' });
   runWASI({ test: 'freopen', stdout: `hello from input2.txt${checkoutEOL}` });
   runWASI({ test: 'ftruncate' });