src: implicitly enable namespace in config

marco-ippolito · Nov 21, 2025 · Nov 21, 2025 · Nov 21, 2025 · Nov 21, 2025 · Nov 21, 2025
commit 95f4f389ef90f090c5c2fea3dde11366d4d6bf57
diff --git a/doc/api/cli.md b/doc/api/cli.md
@@ -1029,7 +1029,40 @@ The configuration file supports namespace-specific options:
 
 * The `nodeOptions` field contains CLI flags that are allowed in [`NODE_OPTIONS`][].
 
-* Namespace fields like `test` contain configuration specific to that subsystem.
+* Namespace fields like `test`, `watch`, and `permission` contain configuration specific to that subsystem.
+
+When a namespace is present in the
+configuration file, Node.js automatically enables the corresponding flag
+(e.g., `--test`, `--watch`, `--permission`). This allows you to configure
+subsystem-specific options without explicitly passing the flag on the command line.
+
+For example:
+
+```json
+{
+  "test": {
+    "test-isolation": "process"
+  }
+}
+```
+
+is equivalent to:
+
+```bash
+node --test --test-isolation=process
+```
+
+To disable the automatic flag while still using namespace options, you can
+explicitly set the flag to `false` within the namespace:
+
+```json
+{
+  "test": {
+    "test": false,
+    "test-isolation": "process"
+  }
+}
+```
 
 No-op flags are not supported.
 Not all V8 flags are currently supported.

diff --git a/doc/api/permissions.md b/doc/api/permissions.md
@@ -175,10 +175,11 @@ Example `node.config.json`:
 }
 ```
 
-Run with the configuration file:
+When the `permission` namespace is present in the configuration file, Node.js
+automatically enables the `--permission` flag. Run with:
 
 ```console
-$ node --permission --experimental-default-config-file app.js
+$ node --experimental-default-config-file app.js
 ```
 
 #### Using the Permission Model with `npx`

diff --git a/src/node_config_file.cc b/src/node_config_file.cc
@@ -255,6 +255,9 @@ ParseResult ConfigReader::ParseConfig(const std::string_view& config_path) {
                                                    available_namespaces.end());
   // Create a set to track unique options
   std::unordered_set<std::string> unique_options;
+  // Namespaces in OPTION_NAMESPACE_LIST
+  std::unordered_set<std::string> namespaces_with_implicit_flags;
+
   // Iterate through the main object to find all namespaces
   for (auto field : main_object) {
     std::string_view field_name;
@@ -281,6 +284,15 @@ ParseResult ConfigReader::ParseConfig(const std::string_view& config_path) {
       continue;
     }
 
+    // List of implicit namespace flags
+    for (auto ns_enum : options_parser::AllNamespaces()) {
+      std::string ns_str = options_parser::NamespaceEnumToString(ns_enum);
+      if (!ns_str.empty() && namespace_name == ns_str) {
+        namespaces_with_implicit_flags.insert(namespace_name);
+        break;
+      }
+    }
+
     // Get the namespace object
     simdjson::ondemand::object namespace_object;
     auto field_error = field.value().get_object().get(namespace_object);
@@ -302,6 +314,17 @@ ParseResult ConfigReader::ParseConfig(const std::string_view& config_path) {
     }
   }
 
+  // Add implicit flags for namespaces (--test, --permission, --watch)
+  // These flags are automatically enabled when their namespace is present
+  for (const auto& ns : namespaces_with_implicit_flags) {
+    std::string flag = "--" + ns;
+    std::string no_flag = "--no-" + ns;
+    // We skip if the user has already set the flag or its negation
+    if (!unique_options.contains(flag) && !unique_options.contains(no_flag)) {
+      namespace_options_.push_back(flag);
+    }
+  }
+
   return ParseResult::Valid;
 }
 

diff --git a/test/fixtures/options-as-flags/test-config.json b/test/fixtures/options-as-flags/test-config.json
@@ -4,6 +4,7 @@
     "max-http-header-size": 8192
   },
   "test": {
+    "test": false,
     "test-isolation": "none"
   }
 }
diff --git a/test/fixtures/rc/empty-valid-namespace.json b/test/fixtures/rc/empty-valid-namespace.json
@@ -1,3 +1,3 @@
 {
-    "test": {}
+    "permission": {}
 }
diff --git a/test/fixtures/rc/permission-namespace.json b/test/fixtures/rc/permission-namespace.json
@@ -0,0 +1,5 @@
+{
+  "permission": {
+    "allow-fs-read": "*"
+  }
+}
diff --git a/test/fixtures/rc/test-namespace-explicit-false.json b/test/fixtures/rc/test-namespace-explicit-false.json
@@ -0,0 +1,6 @@
+{
+  "test": {
+    "test": false,
+    "test-isolation": "none"
+  }
+}
diff --git a/test/fixtures/rc/watch-namespace.json b/test/fixtures/rc/watch-namespace.json
@@ -0,0 +1,5 @@
+{
+  "watch": {
+    "watch-preserve-output": true
+  }
+}
diff --git a/test/parallel/test-config-file.js b/test/parallel/test-config-file.js
@@ -407,6 +407,7 @@ describe('namespace-scoped options', () => {
       '--expose-internals',
       '--experimental-config-file',
       fixtures.path('rc/namespaced/node.config.json'),
+      '--no-test',
       '-p', 'require("internal/options").getOptionValue("--test-isolation")',
     ]);
     assert.strictEqual(result.stderr, '');
@@ -483,6 +484,7 @@ describe('namespace-scoped options', () => {
       '--test-isolation', 'process',
       '--experimental-config-file',
       fixtures.path('rc/namespaced/node.config.json'),
+      '--no-test',
       '-p', 'require("internal/options").getOptionValue("--test-isolation")',
     ]);
     assert.strictEqual(result.stderr, '');
@@ -498,6 +500,7 @@ describe('namespace-scoped options', () => {
       '--test-coverage-exclude', 'cli-pattern2',
       '--experimental-config-file',
       fixtures.path('rc/namespace-with-array.json'),
+      '--no-test',
       '-p', 'JSON.stringify(require("internal/options").getOptionValue("--test-coverage-exclude"))',
     ]);
     assert.strictEqual(result.stderr, '');
@@ -520,6 +523,7 @@ describe('namespace-scoped options', () => {
       '--expose-internals',
       '--experimental-config-file',
       fixtures.path('rc/namespace-with-disallowed-envvar.json'),
+      '--no-test',
       '-p', 'require("internal/options").getOptionValue("--test-concurrency")',
     ]);
     assert.strictEqual(result.stderr, '');
@@ -536,6 +540,7 @@ describe('namespace-scoped options', () => {
       '--test-concurrency', '2',
       '--experimental-config-file',
       fixtures.path('rc/namespace-with-disallowed-envvar.json'),
+      '--no-test',
       '-p', 'require("internal/options").getOptionValue("--test-concurrency")',
     ]);
     assert.strictEqual(result.stderr, '');
@@ -554,4 +559,41 @@ describe('namespace-scoped options', () => {
     assert.strictEqual(result.stdout, '');
     assert.strictEqual(result.code, 9);
   });
+
+  it('should automatically enable --test flag when test namespace is present', async () => {
+    const result = await spawnPromisified(process.execPath, [
+      '--no-warnings',
+      '--experimental-config-file',
+      fixtures.path('rc/namespaced/node.config.json'),
+      fixtures.path('rc/test.js'),
+    ]);
+    assert.strictEqual(result.code, 0);
+    assert.match(result.stdout, /tests 1/);
+  });
+
+  it('should automatically enable --permission flag when permission namespace is present', async () => {
+    const result = await spawnPromisified(process.execPath, [
+      '--no-warnings',
+      '--expose-internals',
+      '--experimental-config-file',
+      fixtures.path('rc/permission-namespace.json'),
+      '-p', 'require("internal/options").getOptionValue("--permission")',
+    ]);
+    assert.strictEqual(result.stderr, '');
+    assert.strictEqual(result.stdout, 'true\n');
+    assert.strictEqual(result.code, 0);
+  });
+
+  it('should respect explicit test: false in test namespace', async () => {
+    const result = await spawnPromisified(process.execPath, [
+      '--no-warnings',
+      '--expose-internals',
+      '--experimental-config-file',
+      fixtures.path('rc/test-namespace-explicit-false.json'),
+      '-p', 'require("internal/options").getOptionValue("--test")',
+    ]);
+    assert.strictEqual(result.stderr, '');
+    assert.strictEqual(result.stdout, 'false\n');
+    assert.strictEqual(result.code, 0);
+  });
 });