fs: unexpose internal constants

`EXTENSIONLESS_FORMAT_JAVASCRIPT` and `EXTENSIONLESS_FORMAT_WASM` are
only used internally through binding `getFormatOfExtensionlessFile`.
They should not be exposed publicly.

PR-URL: https://github.com/nodejs/node/pull/58327
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: LiviaMedeiros <livia@cirno.name>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Juan José Arboleda <soyjuanarbol@gmail.com>

lib/internal/modules/esm/formats.js

@@ -7,7 +7,7 @@ const {
 const { getOptionValue } = require('internal/options');
 const { getValidatedPath } = require('internal/fs/utils');
 const fsBindings = internalBinding('fs');
-const { fs: fsConstants } = internalBinding('constants');
+const { internal: internalConstants } = internalBinding('constants');
 
 const experimentalWasmModules = getOptionValue('--experimental-wasm-modules');
 const experimentalAddonModules = getOptionValue('--experimental-addon-modules');
@@ -60,7 +60,7 @@ function getFormatOfExtensionlessFile(url) {
   if (!experimentalWasmModules) { return 'module'; }
   const path = getValidatedPath(url);
   switch (fsBindings.getFormatOfExtensionlessFile(path)) {
-    case fsConstants.EXTENSIONLESS_FORMAT_WASM:
+    case internalConstants.EXTENSIONLESS_FORMAT_WASM:
       return 'wasm';
     default:
       return 'module';

src/node_constants.cc

@@ -1041,7 +1041,7 @@ void DefineCryptoConstants(Local<Object> target) {
 #endif
 }
 
-void DefineSystemConstants(Local<Object> target) {
+void DefineFsConstants(Local<Object> target) {
   NODE_DEFINE_CONSTANT(target, UV_FS_SYMLINK_DIR);
   NODE_DEFINE_CONSTANT(target, UV_FS_SYMLINK_JUNCTION);
   // file access modes
@@ -1059,10 +1059,6 @@ void DefineSystemConstants(Local<Object> target) {
   NODE_DEFINE_CONSTANT(target, UV_DIRENT_CHAR);
   NODE_DEFINE_CONSTANT(target, UV_DIRENT_BLOCK);
 
-  // Define module specific constants
-  NODE_DEFINE_CONSTANT(target, EXTENSIONLESS_FORMAT_JAVASCRIPT);
-  NODE_DEFINE_CONSTANT(target, EXTENSIONLESS_FORMAT_WASM);
-
   NODE_DEFINE_CONSTANT(target, S_IFMT);
   NODE_DEFINE_CONSTANT(target, S_IFREG);
   NODE_DEFINE_CONSTANT(target, S_IFDIR);
@@ -1250,6 +1246,12 @@ void DefineDLOpenConstants(Local<Object> target) {
 #endif
 }
 
+void DefineInternalConstants(Local<Object> target) {
+  // Define module specific constants
+  NODE_DEFINE_CONSTANT(target, EXTENSIONLESS_FORMAT_JAVASCRIPT);
+  NODE_DEFINE_CONSTANT(target, EXTENSIONLESS_FORMAT_WASM);
+}
+
 void DefineTraceConstants(Local<Object> target) {
   NODE_DEFINE_CONSTANT(target, TRACE_EVENT_PHASE_BEGIN);
   NODE_DEFINE_CONSTANT(target, TRACE_EVENT_PHASE_END);
@@ -1307,16 +1309,19 @@ void CreatePerContextProperties(Local<Object> target,
       Object::New(isolate, Null(isolate), nullptr, nullptr, 0);
   Local<Object> trace_constants =
       Object::New(isolate, Null(isolate), nullptr, nullptr, 0);
+  Local<Object> internal_constants =
+      Object::New(isolate, Null(isolate), nullptr, nullptr, 0);
 
   DefineErrnoConstants(err_constants);
   DefineWindowsErrorConstants(err_constants);
   DefineSignalConstants(sig_constants);
   DefinePriorityConstants(priority_constants);
-  DefineSystemConstants(fs_constants);
+  DefineFsConstants(fs_constants);
   DefineCryptoConstants(crypto_constants);
   DefineZlibConstants(zlib_constants);
   DefineDLOpenConstants(dlopen_constants);
   DefineTraceConstants(trace_constants);
+  DefineInternalConstants(internal_constants);
 
   // Define libuv constants.
   NODE_DEFINE_CONSTANT(os_constants, UV_UDP_REUSEADDR);
@@ -1362,6 +1367,11 @@ void CreatePerContextProperties(Local<Object> target,
             FIXED_ONE_BYTE_STRING(isolate, "trace"),
             trace_constants)
       .Check();
+  target
+      ->Set(env->context(),
+            FIXED_ONE_BYTE_STRING(isolate, "internal"),
+            internal_constants)
+      .Check();
 }
 
 }  // namespace constants

test/parallel/test-binding-constants.js

@@ -7,7 +7,7 @@ const constants = internalBinding('constants');
 const assert = require('assert');
 
 assert.deepStrictEqual(
-  Object.keys(constants).sort(), ['crypto', 'fs', 'os', 'trace', 'zlib']
+  Object.keys(constants).sort(), ['crypto', 'fs', 'internal', 'os', 'trace', 'zlib']
 );
 
 assert.deepStrictEqual(
@@ -28,6 +28,6 @@ function test(obj) {
 }
 
 [
-  constants, constants.crypto, constants.fs, constants.os, constants.trace,
+  constants, constants.crypto, constants.fs, constants.internal, constants.os, constants.trace,
   constants.zlib, constants.os.dlopen, constants.os.errno, constants.os.signals,
 ].forEach(test);

test/parallel/test-fs-constants.js

@@ -6,3 +6,72 @@ const assert = require('assert');
 // Check if the two constants accepted by chmod() on Windows are defined.
 assert.notStrictEqual(fs.constants.S_IRUSR, undefined);
 assert.notStrictEqual(fs.constants.S_IWUSR, undefined);
+
+// Check null prototype.
+assert.strictEqual(Object.getPrototypeOf(fs.constants), null);
+
+const knownFsConstantNames = [
+  'UV_FS_SYMLINK_DIR',
+  'UV_FS_SYMLINK_JUNCTION',
+  'O_RDONLY',
+  'O_WRONLY',
+  'O_RDWR',
+  'UV_DIRENT_UNKNOWN',
+  'UV_DIRENT_FILE',
+  'UV_DIRENT_DIR',
+  'UV_DIRENT_LINK',
+  'UV_DIRENT_FIFO',
+  'UV_DIRENT_SOCKET',
+  'UV_DIRENT_CHAR',
+  'UV_DIRENT_BLOCK',
+  'S_IFMT',
+  'S_IFREG',
+  'S_IFDIR',
+  'S_IFCHR',
+  'S_IFBLK',
+  'S_IFIFO',
+  'S_IFLNK',
+  'S_IFSOCK',
+  'O_CREAT',
+  'O_EXCL',
+  'UV_FS_O_FILEMAP',
+  'O_NOCTTY',
+  'O_TRUNC',
+  'O_APPEND',
+  'O_DIRECTORY',
+  'O_EXCL',
+  'O_NOATIME',
+  'O_NOFOLLOW',
+  'O_SYNC',
+  'O_DSYNC',
+  'O_SYMLINK',
+  'O_DIRECT',
+  'O_NONBLOCK',
+  'S_IRWXU',
+  'S_IRUSR',
+  'S_IWUSR',
+  'S_IXUSR',
+  'S_IRWXG',
+  'S_IRGRP',
+  'S_IWGRP',
+  'S_IXGRP',
+  'S_IRWXO',
+  'S_IROTH',
+  'S_IWOTH',
+  'S_IXOTH',
+  'F_OK',
+  'R_OK',
+  'W_OK',
+  'X_OK',
+  'UV_FS_COPYFILE_EXCL',
+  'COPYFILE_EXCL',
+  'UV_FS_COPYFILE_FICLONE',
+  'COPYFILE_FICLONE',
+  'UV_FS_COPYFILE_FICLONE_FORCE',
+  'COPYFILE_FICLONE_FORCE',
+];
+const fsConstantNames = Object.keys(fs.constants);
+const unknownFsConstantNames = fsConstantNames.filter((constant) => {
+  return !knownFsConstantNames.includes(constant);
+});
+assert.deepStrictEqual(unknownFsConstantNames, [], `Unknown fs.constants: ${unknownFsConstantNames.join(', ')}`);

typings/internalBinding/constants.d.ts

@@ -191,8 +191,6 @@ export interface ConstantsBinding {
     COPYFILE_FICLONE: 2;
     UV_FS_COPYFILE_FICLONE_FORCE: 4;
     COPYFILE_FICLONE_FORCE: 4;
-    EXTENSIONLESS_FORMAT_JAVASCRIPT: 0;
-    EXTENSIONLESS_FORMAT_WASM: 1;
   };
   crypto: {
     OPENSSL_VERSION_NUMBER: 269488319;
@@ -389,4 +387,8 @@ export interface ConstantsBinding {
     TRACE_EVENT_PHASE_LEAVE_CONTEXT: 41;
     TRACE_EVENT_PHASE_LINK_IDS: 61;
   };
+  internal: {
+    EXTENSIONLESS_FORMAT_JAVASCRIPT: 0;
+    EXTENSIONLESS_FORMAT_WASM: 1;
+  };
 }

typings/internalBinding/fs.d.ts

@@ -235,7 +235,7 @@ declare namespace InternalFSBinding {
   function writeString(fd: number, value: string, pos: unknown, encoding: unknown, req: undefined, ctx: FSSyncContext): number;
   function writeString(fd: number, value: string, pos: unknown, encoding: unknown, usePromises: typeof kUsePromises): Promise<number>;
 
-  function getFormatOfExtensionlessFile(url: string): ConstantsBinding['fs'];
+  function getFormatOfExtensionlessFile(url: string): ConstantsBinding['internal'];
 
   function writeFileUtf8(path: string, data: string, flag: number, mode: number): void;
   function writeFileUtf8(fd: number, data: string, flag: number, mode: number): void;