ref: Use the VM to execute local config files

src/config.ts

@@ -1,4 +1,5 @@
 import * as echarts from 'echarts';
+import {promises as fsPromises} from 'node:fs';
 import path from 'node:path';
 import {runInNewContext} from 'node:vm';
 
@@ -24,6 +25,14 @@ async function loadViaHttp(url: string, ac?: AbortController) {
 
   const configJavascript = await resp.text();
 
+  return evalConfigFile(configJavascript);
+}
+
+/**
+ * Loads a config file by using the vm module to execute the file cotnents as a
+ * string.
+ */
+function evalConfigFile(configJavascript: string) {
   const exports = {default: null};
   const module = {exports};
 
@@ -77,7 +86,7 @@ export class ConfigService {
    */
   async fetchConfig(deadline: number) {
     if (!this.configIsViaHttp) {
-      return require(/* webpackIgnore: true */ path.resolve(this.#uri)).default;
+      return evalConfigFile(await fsPromises.readFile(path.resolve(this.#uri), 'utf8'));
     }
 
     let config: any = null;

tests/config.spec.ts

@@ -1,68 +1,75 @@
 import fetchMock from 'jest-fetch-mock';
+import {promises as fsPromises} from 'node:fs';
 
 fetchMock.enableMocks();
 
 import {ConfigService} from 'app/config';
 
+jest.mock('node:fs', () => ({
+  ...jest.requireActual('node:fs'),
+  promises: {readFile: jest.fn()},
+}));
+
 describe('config', () => {
   beforeEach(() => {
     fetchMock.resetMocks();
   });
 
   it('can load config via files', async () => {
-    const init = jest.fn();
-    jest.mock(
-      '/myConfig',
-      () => {
-        const renderConfig = new Map();
-        renderConfig.set('fileExample', {
-          key: 'fileExample',
-          height: 200,
-          width: 100,
-          getOption: (series: any) => ({series}),
-        });
-
-        return {default: {renderConfig, init, version: 'abc'}};
-      },
-      {virtual: true}
-    );
+    const configModule = `
+    var renderConfig = new Map();
+    renderConfig.set('fileExample', {
+      key: 'example',
+      height: 200,
+      width: 100,
+      getOption: series => ({series}),
+    });
+
+    module.exports = {renderConfig, version: 'abc'};`;
+
+    jest.mocked(fsPromises.readFile).mockResolvedValue(Buffer.from(configModule));
 
     const config = new ConfigService('/myConfig');
     await config.resolveEnsured();
 
+    expect(fsPromises.readFile).toHaveBeenCalledWith('/myConfig', 'utf8');
     expect(config.getConfig('fileExample')?.height).toEqual(200);
-    expect(init).toHaveBeenCalledTimes(1);
   });
 
   it('does not require init', async () => {
-    jest.mock(
-      '/myConfig',
-      () => {
-        const renderConfig = new Map();
-        renderConfig.set('fileExample', {
-          key: 'fileExample',
-          height: 200,
-          width: 100,
-          getOption: (series: any) => ({series}),
-        });
-
-        return {default: {renderConfig, version: 'abc'}};
-      },
-      {virtual: true}
-    );
+    const configModule = `
+    var renderConfig = new Map();
+    renderConfig.set('example', {
+      key: 'example',
+      height: 200,
+      width: 100,
+      getOption: series => ({series}),
+    });
+
+    module.exports = {
+      renderConfig,
+      version: 'abc',
+      init: _ => console.log('init called')
+    };`;
+
+    const consoleSpy = jest.spyOn(console, 'log');
+    consoleSpy.mockImplementation(() => {});
+
+    jest.mocked(fsPromises.readFile).mockResolvedValue(Buffer.from(configModule));
 
     const config = new ConfigService('/myConfig');
     await config.resolveEnsured();
 
-    expect(config.getConfig('fileExample')?.height).toEqual(200);
+    expect(config.getConfig('example')?.height).toEqual(200);
+    expect(consoleSpy).toHaveBeenCalledWith('init called');
   });
 
   it('can load config via http', async () => {
     const configModule = `
     var renderConfig = new Map();
     renderConfig.set('example', {
       key: 'example',
-      height: 100,
+      height: 200,
       width: 100,
       getOption: series => ({series}),
     });
@@ -75,6 +82,6 @@ describe('config', () => {
     await config.resolveEnsured();
 
     expect(fetchMock.mock.calls[0][0]).toEqual('https://example.com/myConfig.js');
-    expect(config.getConfig('example')?.height).toEqual(100);
+    expect(config.getConfig('example')?.height).toEqual(200);
   });
 });