Fix module resolution failure when outside main module

We now depend on `require.resolve` instead of `require.main`.

Closes #30

Author: rubensworks

lib/construction/strategy/ConstructionStrategyCommonJs.ts

@@ -29,13 +29,10 @@ export class ConstructionStrategyCommonJs implements IConstructionStrategy<any>
     try {
       object = this.requireCurrentRunningModuleIfCurrent(options.moduleState, options.requireName);
     } catch {
-      if (!this.req.main) {
-        throw new Error(`Corrupt Node.js state: Could not find a main module.`);
-      }
       // Always require relative from main module, because Components.js will in most cases just be dependency.
-      object = this.req.main.require(options.requireName.startsWith('.') ?
+      object = this.req(options.requireName.startsWith('.') ?
         Path.join(process.cwd(), options.requireName) :
-        options.requireName);
+        this.req.resolve(options.requireName, { paths: [ options.moduleState.mainModulePath ]}));
     }
 
     // Determine the child of the require'd element

test/integration/instantiateFile-test.ts

@@ -14,7 +14,7 @@ describe('construction with component configs as files', () => {
   let manager: ComponentsManager<any>;
   beforeEach(async() => {
     moduleState = <any> {
-      mainModulePath: __dirname,
+      mainModulePath: Path.posix.join(__dirname, '../../__mocks__'),
       importPaths: {
         'http://example.org/': `${__dirname}/../`,
       },

test/integration/instantiateResourceConfigComponent-test.ts

@@ -1,3 +1,4 @@
+import * as Path from 'path';
 import type { Resource, RdfObjectLoader } from 'rdf-object';
 import { mocked } from 'ts-jest/utils';
 import { ComponentsManager } from '../../lib/ComponentsManager';
@@ -19,8 +20,10 @@ describe('construction with component configs as Resource', () => {
   let settings: IConstructionSettings;
   beforeEach(async() => {
     manager = await ComponentsManager.build({
-      mainModulePath: __dirname,
-      moduleState: <any> {},
+      mainModulePath: Path.posix.join(__dirname, '../../__mocks__'),
+      moduleState: <any> {
+        mainModulePath: Path.posix.join(__dirname, '../../__mocks__'),
+      },
       async moduleLoader() {
         // Register nothing
       },

test/integration/instantiateResourceConfigComponentMapped-test.ts

@@ -1,3 +1,4 @@
+import * as Path from 'path';
 import type { Resource, RdfObjectLoader } from 'rdf-object';
 import { mocked } from 'ts-jest/utils';
 import { ComponentsManager } from '../../lib/ComponentsManager';
@@ -21,8 +22,10 @@ describe('construction with mapped component configs as Resource', () => {
   let settings: IConstructionSettings;
   beforeEach(async() => {
     manager = await ComponentsManager.build({
-      mainModulePath: __dirname,
-      moduleState: <any> {},
+      mainModulePath: Path.posix.join(__dirname, '../../__mocks__'),
+      moduleState: <any> {
+        mainModulePath: Path.posix.join(__dirname, '../../__mocks__'),
+      },
       async moduleLoader() {
         // Register nothing
       },

test/integration/instantiateResourceConfigRaw-test.ts

@@ -1,3 +1,4 @@
+import * as Path from 'path';
 import type { RdfObjectLoader } from 'rdf-object';
 import { ComponentsManager } from '../../lib/ComponentsManager';
 import type { IConfigConstructorPool } from '../../lib/construction/IConfigConstructorPool';
@@ -19,8 +20,10 @@ describe('construction with component configs as Resource', () => {
   let settings: IConstructionSettings;
   beforeEach(async() => {
     manager = await ComponentsManager.build({
-      mainModulePath: __dirname,
-      moduleState: <any> {},
+      mainModulePath: Path.posix.join(__dirname, '../../__mocks__'),
+      moduleState: <any> {
+        mainModulePath: Path.posix.join(__dirname, '../../__mocks__'),
+      },
       async moduleLoader() {
         // Register nothing
       },

test/unit/construction/strategy/ConstructionStrategyCommonJs-test.ts

@@ -48,19 +48,15 @@ describe('ConstructionStrategyCommonJs', () => {
       if (path === 'mainmodulepath/unknown.js') {
         return;
       }
-      return true;
-    });
-    req.main = <any> {
-      require(path: string) {
-        if (path === 'othermodule') {
-          return requireOther;
-        }
-        if (Path.join(process.cwd(), 'myfile.js')) {
-          return requireFile;
-        }
-        throw new Error(`Main require not found for ${path}`);
-      },
-    };
+      if (path === 'othermodule') {
+        return requireOther;
+      }
+      if (Path.join(process.cwd(), 'myfile.js')) {
+        return requireFile;
+      }
+      throw new Error(`Require not found for ${path}`);
+    });
+    req.resolve = <any> ((arg: string) => arg);
     moduleState = {
       componentModules: {},
       contexts: {},
@@ -175,19 +171,6 @@ describe('ConstructionStrategyCommonJs', () => {
       })).toThrow(new Error('Failed to get module element a.X from module currentmodule'));
     });
 
-    it('without requireElement and constructor in another module with undefined req.main should throw', () => {
-      req.main = undefined;
-      expect(() => constructionStrategy.createInstance({
-        settings,
-        moduleState,
-        requireName: 'othermodule',
-        requireElement: undefined,
-        callConstructor: false,
-        args: [],
-        instanceId: 'myinstance',
-      })).toThrow(new Error(`Corrupt Node.js state: Could not find a main module.`));
-    });
-
     it('with requireElement to class and without constructor in the current module', () => {
       expect(constructionStrategy.createInstance({
         settings,