src: enable wrapping Napi namespace with custom namespace

napi-inl.h

@@ -18,6 +18,10 @@
 
 namespace Napi {
 
+#ifdef NAPI_CPP_CUSTOM_NAMESPACE
+namespace NAPI_CPP_CUSTOM_NAMESPACE {
+#endif
+
 // Helpers to handle functions exposed from C++.
 namespace details {
 
@@ -6213,6 +6217,10 @@ bool Env::CleanupHook<Hook, Arg>::IsEmpty() const {
 }
 #endif  // NAPI_VERSION > 2
 
+#ifdef NAPI_CPP_CUSTOM_NAMESPACE
+}  // namespace NAPI_CPP_CUSTOM_NAMESPACE
+#endif
+
 } // namespace Napi
 
 #endif // SRC_NAPI_INL_H_

napi.h

@@ -140,6 +140,18 @@ static_assert(sizeof(char16_t) == sizeof(wchar_t), "Size mismatch between char16
 ////////////////////////////////////////////////////////////////////////////////
 namespace Napi {
 
+#ifdef NAPI_CPP_CUSTOM_NAMESPACE
+// NAPI_CPP_CUSTOM_NAMESPACE can be #define'd per-addon to avoid symbol
+// conflicts between different instances of node-addon-api
+
+// First dummy definition of the namespace to make sure that Napi::(name) still
+// refers to the right things inside this file.
+namespace NAPI_CPP_CUSTOM_NAMESPACE {}
+using namespace NAPI_CPP_CUSTOM_NAMESPACE;
+
+namespace NAPI_CPP_CUSTOM_NAMESPACE {
+#endif
+
   // Forward declarations
   class Env;
   class Value;
@@ -2977,6 +2989,10 @@ namespace Napi {
   };
 #endif  // NAPI_VERSION > 5
 
+#ifdef NAPI_CPP_CUSTOM_NAMESPACE
+  }  // namespace NAPI_CPP_CUSTOM_NAMESPACE
+#endif
+
 } // namespace Napi
 
 // Inline implementations of all the above class methods are included here.

package.json

@@ -323,7 +323,6 @@
       "name": "WenheLI",
       "url": "https://github.com/WenheLI"
     },
-
     {
       "name": "Yohei Kishimoto",
       "url": "https://github.com/morokosi"

test/binding.gyp

@@ -114,5 +114,11 @@
       'sources': ['>@(build_sources_swallowexcept)'],
       'defines': ['NODE_API_SWALLOW_UNTHROWABLE_EXCEPTIONS']
     },
+    {
+      'target_name': 'binding_custom_namespace',
+      'includes': ['../noexcept.gypi'],
+      'sources': ['>@(build_sources)'],
+      'defines': ['NAPI_CPP_CUSTOM_NAMESPACE=cstm']
+    },
   ],
 }

test/common/index.js

@@ -81,7 +81,8 @@ exports.runTest = async function (test, buildType, buildPathRoot = process.env.B
   const bindings = [
     path.join(buildPathRoot, `../build/${buildType}/binding.node`),
     path.join(buildPathRoot, `../build/${buildType}/binding_noexcept.node`),
-    path.join(buildPathRoot, `../build/${buildType}/binding_noexcept_maybe.node`)
+    path.join(buildPathRoot, `../build/${buildType}/binding_noexcept_maybe.node`),
+    path.join(buildPathRoot, `../build/${buildType}/binding_custom_namespace.node`)
   ].map(it => require.resolve(it));
 
   for (const item of bindings) {
@@ -96,7 +97,8 @@ exports.runTestWithBindingPath = async function (test, buildType, buildPathRoot
   const bindings = [
     path.join(buildPathRoot, `../build/${buildType}/binding.node`),
     path.join(buildPathRoot, `../build/${buildType}/binding_noexcept.node`),
-    path.join(buildPathRoot, `../build/${buildType}/binding_noexcept_maybe.node`)
+    path.join(buildPathRoot, `../build/${buildType}/binding_noexcept_maybe.node`),
+    path.join(buildPathRoot, `../build/${buildType}/binding_custom_namespace.node`)
   ].map(it => require.resolve(it));
 
   for (const item of bindings) {

test/common/test_helper.h

@@ -3,6 +3,12 @@
 
 namespace Napi {
 
+// Needs this here since the MaybeUnwrap() functions need to be in the
+// same namespace as their arguments for C++ argument-dependent lookup
+#ifdef NAPI_CPP_CUSTOM_NAMESPACE
+namespace NAPI_CPP_CUSTOM_NAMESPACE {
+#endif
+
 // Use this when a variable or parameter is unused in order to explicitly
 // silence a compiler warning about that.
 template <typename T>
@@ -58,4 +64,8 @@ inline bool MaybeUnwrapTo(MaybeOrValue<T> maybe, T* out) {
 #endif
 }
 
+#ifdef NAPI_CPP_CUSTOM_NAMESPACE
+}  // namespace NAPI_CPP_CUSTOM_NAMESPACE
+#endif
+
 }  // namespace Napi

test/error_terminating_environment.js

@@ -70,6 +70,7 @@ test(`./build/${buildType}/binding.node`, true);
 test(`./build/${buildType}/binding_noexcept.node`, true);
 test(`./build/${buildType}/binding_swallowexcept.node`, false);
 test(`./build/${buildType}/binding_swallowexcept_noexcept.node`, false);
+test(`./build/${buildType}/binding_custom_namespace.node`, true);
 
 function test(bindingPath, process_should_abort) {
   const number_of_test_cases = 5;

unit-test/binding.gyp

@@ -11,23 +11,23 @@
   },
   'targets': [
     {
-			"target_name": "generateBindingCC",
-			"type": "none",
-			"actions": [ {
-				"action_name": "generateBindingCC",
-				"message": "Generating binding cc file",
-				"outputs": ["generated/binding.cc"],
-				"conditions": [
-					[ "'true'=='true'", {
-						"inputs": [""],
-						"action": [
-							"node",
-							"generate-binding-cc.js",
+      "target_name": "generateBindingCC",
+      "type": "none",
+      "actions": [ {
+        "action_name": "generateBindingCC",
+        "message": "Generating binding cc file",
+        "outputs": ["generated/binding.cc"],
+        "conditions": [
+          [ "'true'=='true'", {
+            "inputs": [""],
+            "action": [
+              "node",
+              "generate-binding-cc.js",
               "<!@(node -p \"require('./injectTestParams').filesForBinding()\" )"
-						]
-					} ]
-				]
-			} ]
+            ]
+          } ]
+        ]
+      } ]
     },
     {
       'target_name': 'binding',
@@ -61,5 +61,12 @@
       'defines': ['NODE_API_SWALLOW_UNTHROWABLE_EXCEPTIONS'],
       'dependencies': [ 'generateBindingCC' ]
     },
+    {
+      'target_name': 'binding_custom_namespace',
+      'includes': ['../noexcept.gypi'],
+      'sources': ['>@(build_sources)'],
+      'defines': ['NAPI_CPP_CUSTOM_NAMESPACE=cstm'],
+      'dependencies': [ 'generateBindingCC' ]
+    },
   ],
 }