src: allow empty --experimental-config-file

Author: marco-ippolito

doc/api/cli.md

@@ -1014,7 +1014,7 @@ added:
 
 Enable experimental import support for `.node` addons.
 
-### `--experimental-config-file=config`
+### `--experimental-config-file[=config]`
 
 <!-- YAML
 added:
@@ -1025,6 +1025,8 @@ added:
 > Stability: 1.0 - Early development
 
 If present, Node.js will look for a configuration file at the specified path.
+If the path is not specified, Node.js will look for a `node.config.json` file
+in the current working directory (equivalent to `--experimental-default-config-file`).
 Node.js will read the configuration file and apply the settings. The
 configuration file should be a JSON file with the following structure. `vX.Y.Z`
 in the `$schema` must be replaced with the version of Node.js you are using.
@@ -1131,9 +1133,10 @@ added:
 
 > Stability: 1.0 - Early development
 
-If the `--experimental-default-config-file` flag is present, Node.js will look for a
+This flag is an alias for `--experimental-config-file` without an argument.
+If present, Node.js will look for a
 `node.config.json` file in the current working directory and load it as a
-as configuration file.
+configuration file.
 
 ### `--experimental-eventsource`
 

doc/node.1

@@ -602,8 +602,10 @@ It is possible to run code containing inline types unless the
 .It Fl -experimental-addon-modules
 Enable experimental import support for \fB.node\fR addons.
 .
-.It Fl -experimental-config-file Ns = Ns Ar config
+.It Fl -experimental-config-file Ns Op = Ns Ar config
 If present, Node.js will look for a configuration file at the specified path.
+If the path is not specified, Node.js will look for a \fBnode.config.json\fR file
+in the current working directory (equivalent to \fB--experimental-default-config-file\fR).
 Node.js will read the configuration file and apply the settings. The
 configuration file should be a JSON file with the following structure. \fBvX.Y.Z\fR
 in the \fB$schema\fR must be replaced with the version of Node.js you are using.
@@ -689,9 +691,10 @@ Node.js will not sanitize or perform validation on the user-provided configurati
 so \fBNEVER\fR use untrusted configuration files.
 .
 .It Fl -experimental-default-config-file
-If the \fB--experimental-default-config-file\fR flag is present, Node.js will look for a
+This flag is an alias for \fB--experimental-config-file\fR without an argument.
+If present, Node.js will look for a
 \fBnode.config.json\fR file in the current working directory and load it as a
-as configuration file.
+configuration file.
 .
 .It Fl -experimental-eventsource
 Enable exposition of EventSource Web API on the global scope.

lib/internal/process/pre_execution.js

@@ -382,7 +382,8 @@ function setupSQLite() {
 
 function initializeConfigFileSupport() {
   if (getOptionValue('--experimental-default-config-file') ||
-      getOptionValue('--experimental-config-file')) {
+      getOptionValue('--experimental-config-file') ||
+      getOptionValue('--experimental-config-file=')) {
     emitExperimentalWarning('--experimental-config-file');
   }
 }

src/node_config_file.cc

@@ -17,13 +17,22 @@ std::optional<std::string_view> ConfigReader::GetDataFromArgs(
   for (auto it = args.begin(); it != args.end(); ++it) {
     if (*it == flag_path) {
       // Case: "--experimental-config-file foo"
-      if (auto next = std::next(it); next != args.end()) {
+      if (auto next = std::next(it);
+          next != args.end() && !next->starts_with("-")) {
         return *next;
       }
+      // Case: "--experimental-config-file" without argument, use default
+      has_default_config_file = true;
     } else if (it->starts_with(flag_path)) {
       // Case: "--experimental-config-file=foo"
       if (it->size() > flag_path.size() && (*it)[flag_path.size()] == '=') {
-        return std::string_view(*it).substr(flag_path.size() + 1);
+        std::string_view value =
+            std::string_view(*it).substr(flag_path.size() + 1);
+        if (value.empty()) {
+          has_default_config_file = true;
+        } else {
+          return value;
+        }
       }
     } else if (*it == default_file || it->starts_with(default_file)) {
       has_default_config_file = true;

src/node_options.cc

@@ -868,12 +868,14 @@ EnvironmentOptionsParser::EnvironmentOptionsParser() {
             "set environment variables from supplied file",
             &EnvironmentOptions::optional_env_file);
   Implies("--env-file-if-exists", "[has_env_file_string]");
-  AddOption("--experimental-config-file",
+  AddOption("--experimental-config-file=",
             "set config file from supplied file",
             &EnvironmentOptions::experimental_config_file_path);
-  AddOption("--experimental-default-config-file",
-            "set config file from default config file",
+  AddOption("--experimental-config-file",
+            "set default config file",
             &EnvironmentOptions::experimental_default_config_file);
+  AddAlias("--experimental-config-file <arg>", "--experimental-config-file=");
+  AddAlias("--experimental-default-config-file", "--experimental-config-file");
   AddOption("--test",
             "launch test runner on startup",
             &EnvironmentOptions::test_runner,

test/parallel/test-config-file.js

@@ -371,6 +371,32 @@ test('should use node.config.json as default', onlyIfNodeOptionsSupport, async (
   assert.strictEqual(result.code, 0);
 });
 
+test('should use node.config.json when --experimental-config-file has no argument', onlyIfNodeOptionsSupport, async () => {
+  const result = await spawnPromisified(process.execPath, [
+    '--no-warnings',
+    '--experimental-config-file',
+    '-p', 'http.maxHeaderSize',
+  ], {
+    cwd: fixtures.path('rc/default'),
+  });
+  assert.strictEqual(result.stderr, '');
+  assert.strictEqual(result.stdout, '10\n');
+  assert.strictEqual(result.code, 0);
+});
+
+test('should use node.config.json when --experimental-config-file= has empty argument', onlyIfNodeOptionsSupport, async () => {
+  const result = await spawnPromisified(process.execPath, [
+    '--no-warnings',
+    '--experimental-config-file=',
+    '-p', 'http.maxHeaderSize',
+  ], {
+    cwd: fixtures.path('rc/default'),
+  });
+  assert.strictEqual(result.stderr, '');
+  assert.strictEqual(result.stdout, '10\n');
+  assert.strictEqual(result.code, 0);
+});
+
 test('should override node.config.json when specificied', onlyIfNodeOptionsSupport, async () => {
   const result = await spawnPromisified(process.execPath, [
     '--no-warnings',