test: require symlinked binary module twice

Attempt to load the binary module disguised
behind two symlinked locations.

Big thanks to Michael Mifsud <[email protected]>
for preparing a proper test case.

test/addons/symlinked-module/binding.cc

@@ -0,0 +1,13 @@
+#include <node.h>
+#include <v8.h>
+
+void Method(const v8::FunctionCallbackInfo<v8::Value>& args) {
+  v8::Isolate* isolate = args.GetIsolate();
+  args.GetReturnValue().Set(v8::String::NewFromUtf8(isolate, "world"));
+}
+
+void init(v8::Local<v8::Object> target) {
+  NODE_SET_METHOD(target, "hello", Method);
+}
+
+NODE_MODULE(binding, init);

test/addons/symlinked-module/binding.gyp

@@ -0,0 +1,8 @@
+{
+  'targets': [
+    {
+      'target_name': 'binding',
+      'sources': [ 'binding.cc' ]
+    }
+  ]
+}

test/addons/symlinked-module/submodule.js

@@ -0,0 +1,10 @@
+'use strict';
+require('../../common');
+const path = require('path');
+const assert = require('assert');
+
+module.exports.test = function(bindingDir) {
+  var mod = require(path.join(bindingDir, 'binding.node'));
+  assert(mod != null);
+  assert(mod.hello() == 'world');
+};

test/addons/symlinked-module/test.js

@@ -0,0 +1,32 @@
+'use strict';
+const common = require('../../common');
+const fs = require('fs');
+const path = require('path');
+const assert = require('assert');
+
+common.refreshTmpDir();
+
+var destDir = path.resolve(common.tmpDir);
+
+var location = [path.join(destDir, 'first'), path.join(destDir, 'second')];
+fs.mkdirSync(location[0]);
+try {
+  fs.symlinkSync(location[0], location[1]);
+} catch (EPERM) {
+  console.log('1..0 # Skipped: module identity test (no privs for symlinks)');
+  return;
+}
+
+const addonPath = path.join(__dirname, 'build', 'Release', 'binding.node');
+
+var contents = fs.readFileSync(addonPath);
+fs.writeFileSync(path.join(location[0], 'binding.node'), contents);
+fs.writeFileSync(path.join(location[1], 'binding.node'), contents);
+
+var primary = require(path.join(location[0], 'binding.node'));
+assert(primary != null);
+assert(primary.hello() == 'world');
+var secondary = require(path.join(location[1], 'binding.node'));
+assert(secondary != null);
+assert(secondary.hello() == 'world');
+require('./submodule').test(location[1]);