Ensure that stdin/stdout/stderr are not mapped 1:1 under NODERAWFS

Previously, when linking with -sNODERAWFS, the stdin, stdout and
stderr streams were respectively attached to file descriptors 0, 1
and 2 of the running Node process.

This implicitly means that overriding the print, printErr, stdin,
stdout and stderr handlers on the incoming module wasn't possible.

This commit ensures that stdin/stdout/stderr uses the library_tty.js
implementation for its printing, which leverages the console object,
whenever the above handlers weren't overriden. This matches what is
done when filesystem support isn't included.

Resolves: #17688.
Resolves: #22264.

src/library_noderawfs.js

@@ -7,7 +7,19 @@
 addToLibrary({
   $NODERAWFS__deps: ['$ERRNO_CODES', '$FS', '$NODEFS', '$mmapAlloc', '$FS_modeStringToFlags'],
   $NODERAWFS__postset: `
-    if (ENVIRONMENT_IS_NODE) {
+    if (!ENVIRONMENT_IS_NODE) {
+      throw new Error("NODERAWFS is currently only supported on Node.js environment.")
+    }
+    // Use this to reference our in-memory filesystem
+    var VFS = Object.assign({}, FS);
+    // Override the init function with our own
+    FS.init = NODERAWFS.init;`,
+  $NODERAWFS: {
+    init(input, output, error) {
+      // Call the original FS.init, this will setup the
+      // stdin, stdout and stderr devices
+      VFS.init(input, output, error);
+
       var _wrapNodeError = function(func) {
         return function(...args) {
           try {
@@ -20,15 +32,14 @@ addToLibrary({
           }
         }
       };
-      /** @suppress {partialAlias} */
-      var VFS = Object.assign({}, FS);
+
+      // Wrap the whole in-memory filesystem API with
+      // our Node.js based functions
       for (var _key in NODERAWFS) {
+        /** @suppress {partialAlias} */
         FS[_key] = _wrapNodeError(NODERAWFS[_key]);
       }
-    } else {
-      throw new Error("NODERAWFS is currently only supported on Node.js environment.")
-    }`,
-  $NODERAWFS: {
+    },
     lookup(parent, name) {
 #if ASSERTIONS
       assert(parent)
@@ -44,12 +55,6 @@ addToLibrary({
       var mode = NODEFS.getMode(path);
       return { path, node: { id: st.ino, mode, node_ops: NODERAWFS, path }};
     },
-    createStandardStreams() {
-      FS.createStream({ nfd: 0, position: 0, path: '', flags: 0, tty: true, seekable: false }, 0);
-      for (var i = 1; i < 3; i++) {
-        FS.createStream({ nfd: i, position: 0, path: '', flags: 577, tty: true, seekable: false }, i);
-      }
-    },
     // generic function for all node creation
     cwd() { return process.cwd(); },
     chdir(...args) { process.chdir(...args); },

test/test_other.py

@@ -1669,6 +1669,7 @@ def test_export_all_and_exported_functions(self):
     'closure': (['-O2', '--closure=1'],),
   })
   @also_with_wasmfs
+  @also_with_noderawfs
   @crossplatform
   def test_stdin(self, args):
     create_file('in.txt', 'abcdef\nghijkl\n')
@@ -13439,6 +13440,7 @@ def test_unistd_pathconf(self):
   def test_unistd_swab(self):
     self.do_run_in_out_file_test('unistd/swab.c')
 
+  @also_with_noderawfs
   def test_unistd_isatty(self):
     self.do_runf('unistd/isatty.c', 'success')
 
@@ -13476,6 +13478,38 @@ def test_unistd_close_noderawfs(self):
     self.emcc_args += ['--pre-js', 'pre.js']
     self.do_run_in_out_file_test('unistd/close.c')
 
+  @requires_node
+  def test_noderawfs_override_standard_streams(self):
+    self.set_setting('NODERAWFS')
+    self.set_setting('FORCE_FILESYSTEM')
+    create_file('pre.js', '''
+let stdout = '';
+let stderr = '';
+
+Module['print'] = (text) => stdout += text;
+Module['printErr'] = (text) => stderr += text;
+Module['postRun'] = () => {
+    assert(stderr == '', 'stderr should be empty. \\n' +
+        'stderr: \\n' + stderr);
+    assert(stdout.startsWith('hello, world!'), 'stdout should start with the famous greeting. \\n' +
+        'stdout: \\n' + stdout);
+}
+''')
+    self.emcc_args += ['--pre-js', 'pre.js']
+    self.do_runf(test_file('hello_world.c'))
+
+  @requires_node
+  def test_noderawfs_override_stdin(self):
+    self.set_setting('NODERAWFS')
+    self.set_setting('FORCE_FILESYSTEM')
+    self.set_setting('EXIT_RUNTIME')
+    create_file('pre.js', '''
+const data = 'hello, world!\\n'.split('').map(c => c.charCodeAt(0));
+Module['stdin'] = () => data.shift() || null;
+''')
+    self.emcc_args += ['--pre-js', 'pre.js']
+    self.do_runf(test_file('module/test_stdin.c'), 'hello, world!')
+
   # WASMFS tests
 
   # TODO: This test will only work with the new file system.

test/unistd/isatty.c

@@ -21,7 +21,11 @@ int main() {
   assert(errno == EBADF);
 
   err = isatty(open("/dev/stdin", O_RDONLY));
+#ifdef NODERAWFS
+  assert(!err);
+#else
   assert(err == 1);
+#endif
 
   err = isatty(open("/dev/null", O_RDONLY));
   assert(!err);