support webpack 5

Author: liady

index.js

@@ -53,7 +53,16 @@ module.exports = function nodeExternals(options) {
     });
 
     // return an externals function
-    return function (context, request, callback) {
+    return function (arg1, arg2, arg3) {
+        var context = arg1;
+        var request = arg2;
+        var callback = arg3;
+        // in case of webpack 5
+        if (arg1 && arg1.context && arg1.request) {
+            context = arg1.context;
+            request = arg1.request;
+            callback = arg2;
+        }
         var moduleName = getModuleName(request, includeAbsolutePaths);
         if (
             utils.contains(nodeModules, moduleName) &&

test/library.spec.js

@@ -5,6 +5,7 @@ var mockNodeModules = testUtils.mockNodeModules;
 var restoreMock = testUtils.restoreMock;
 var context={};
 var assertResult = testUtils.buildAssertion.bind(null, context);
+var assertResultWebpack5 = testUtils.buildAssertionWebpack5.bind(null, context);
 var chai = require('chai');
 var expect = chai.expect;
 
@@ -262,6 +263,40 @@ describe('when modules dir does not exist', function() {
     });
 })
 
+// Test basic functionality
+describe('invocation with no settings - webpack 5', function() {
+
+    before(function(){
+        mockNodeModules();
+        context.instance = nodeExternals();
+    });
+
+    describe('should invoke a commonjs callback', function(){
+        it('when given an existing module', assertResultWebpack5('moduleA', 'commonjs moduleA'));
+        it('when given another existing module', assertResultWebpack5('moduleB', 'commonjs moduleB'));
+        it('when given another existing module for scoped package', assertResultWebpack5('@organisation/moduleA', 'commonjs @organisation/moduleA'));
+        it('when given an existing sub-module', assertResultWebpack5('moduleA/sub-module', 'commonjs moduleA/sub-module'));
+        it('when given an existing file in a sub-module', assertResultWebpack5('moduleA/another-sub/index.js', 'commonjs moduleA/another-sub/index.js'));
+        it('when given an existing file in a scoped package', assertResultWebpack5('@organisation/moduleA/index.js', 'commonjs @organisation/moduleA/index.js'))
+        it('when given an another existing file in a scoped package', assertResultWebpack5('@organisation/base-node/vs/base/common/paths', 'commonjs @organisation/base-node/vs/base/common/paths'))
+
+    });
+
+    describe('should invoke an empty callback', function(){
+        it('when given a non-node module', assertResultWebpack5('non-node-module', undefined));
+        it('when given a module in the file but not in folder', assertResultWebpack5('moduleE', undefined));
+        it('when given a relative path', assertResultWebpack5('./src/index.js', undefined));
+        it('when given a different absolute path', assertResultWebpack5('/test/node_modules/non-node-module', undefined));
+        it('when given a complex different absolute path', assertResultWebpack5('/test/node_modules/non-node-module/node_modules/moduleA', undefined));
+        it('when given an absolute path', assertResultWebpack5('/test/node_modules/moduleA', undefined));
+        it('when given an existing sub-module inside node_modules', assertResultWebpack5('/moduleA/node_modules/moduleB', undefined));
+    });
+
+    after(function(){
+        restoreMock()
+    });
+});
+
 describe('validate options', function () {
     it('should identify misspelled terms', function () {
         var results = utils.validateOptions({ whitelist: [], moduledirs: [] });

test/test-utils.js

@@ -24,6 +24,23 @@ exports.buildAssertion = function buildAssertion(context, moduleName, expectedRe
     };
 }
 
+/**
+ * Creates an assertion function that makes sure to output expectedResult when given moduleName
+ * <<Webpack 5 version>>
+ * @param  {object} context          context object that holds the instance
+ * @param  {string} moduleName       given module name
+ * @param  {string} expectedResult   expected external module string
+ * @return {function}                the assertion function
+ */
+exports.buildAssertionWebpack5 = function buildAssertion(context, moduleName, expectedResult){
+    return function(done) {
+        context.instance({ context: relative(), request: moduleName }, function(noarg, externalModule) {
+            expect(externalModule).to.be.equal(expectedResult);
+            done();
+        })
+    };
+}
+
 /**
  * Mocks the fs module to output a desired structure
  * @param  {object} structure       the requested structure