module: warn on invalid package.json type field

Add validation to warn users when the "type" field in package.json
contains an invalid value. Previously, values like "CommonJS" (wrong
case) would silently fall back to typeless behavior. Now a clear
warning message is displayed indicating the expected values are
"commonjs" or "module".

Fixes: #60085

Author: Shuklax

src/node_modules.cc

@@ -212,6 +212,15 @@ const BindingData::PackageConfig* BindingData::GetPackageJSON(
       if (value.get_string().get(field_value)) {
         return throw_invalid_package_config();
       }
+
+      if (field_value != "commonjs" && field_value != "module") {
+        fprintf(stderr,
+                "node: [MODULE_INVALID_TYPE] Invalid \"type\" field in package.json: \"%.*s\". "
+                "Expected \"commonjs\" or \"module\".\n",
+                static_cast<int>(field_value.size()),
+                field_value.data());
+      }
+
       // Only update type if it is "commonjs" or "module"
       // The default value is "none" for backward compatibility.
       if (field_value == "commonjs" || field_value == "module") {
@@ -275,7 +284,7 @@ void BindingData::ReadPackageJSON(const FunctionCallbackInfo<Value>& args) {
 
   if (package_json == nullptr) {
     return;
-  }
+  }  
 
   args.GetReturnValue().Set(package_json->Serialize(realm));
 }

test/parallel/test-find-package-json.js

@@ -204,4 +204,68 @@ describe('findPackageJSON', () => { // Throws when no arguments are provided
     assert.ok(stdout.includes(foundPjsonPath), stdout);
     assert.strictEqual(code, 0);
   });
+
+
+});
+
+describe('package.json type field validation', () => {
+  it('should warn for invalid type field values', async () => {
+    tmpdir.refresh();
+
+    fs.mkdirSync(tmpdir.resolve('invalid-type-pkg'), { recursive: true });
+    fs.writeFileSync(
+      tmpdir.resolve('invalid-type-pkg/package.json'),
+      JSON.stringify({ type: 'CommonJS' })
+    );
+    fs.writeFileSync(
+      tmpdir.resolve('invalid-type-pkg/index.js'),
+      'module.exports = 42;'
+    );
+
+    const { stderr } = await common.spawnPromisified(process.execPath, [
+      tmpdir.resolve('invalid-type-pkg/index.js'),
+    ]);
+
+    assert.ok(stderr.includes('MODULE_INVALID_TYPE'));
+    assert.ok(stderr.includes('CommonJS'));
+  });
+
+  it('should not warn for valid type values', async () => {
+    tmpdir.refresh();
+
+    fs.mkdirSync(tmpdir.resolve('valid-type-pkg'), { recursive: true });
+    fs.writeFileSync(
+      tmpdir.resolve('valid-type-pkg/package.json'),
+      JSON.stringify({ type: 'commonjs' })
+    );
+    fs.writeFileSync(
+      tmpdir.resolve('valid-type-pkg/index.js'),
+      'module.exports = 42;'
+    );
+
+    const { stderr } = await common.spawnPromisified(process.execPath, [
+      tmpdir.resolve('valid-type-pkg/index.js'),
+    ]);
+
+    assert.ok(!stderr.includes('MODULE_INVALID_TYPE'));
+  });
+
+  it('should not warn when type field is missing', async () => {
+    tmpdir.refresh();
+    fs.mkdirSync(tmpdir.resolve('no-type-pkg'), { recursive: true });
+    fs.writeFileSync(
+      tmpdir.resolve('no-type-pkg/package.json'),
+      JSON.stringify({ name: 'test' })
+    );
+    fs.writeFileSync(
+      tmpdir.resolve('no-type-pkg/index.js'),
+      'module.exports = 42;'
+    );
+
+    const { stderr } = await common.spawnPromisified(process.execPath, [
+      tmpdir.resolve('no-type-pkg/index.js'),
+    ]);
+
+    assert.ok(!stderr.includes('MODULE_INVALID_TYPE'));
+  });
 });