feat(plugin): add support for mjs and cjs filters

closes #163

README.md

@@ -220,7 +220,7 @@ cy.recordHar({ includeBlobs: false });
 
 > ✴ As of version 6, this flag will be disabled by default.
 
-You can specify the `filter` option as a path to a JS/TS module that exports a function to filter out unwanted entries from the HAR. The function should take an [Entry object](http://www.softwareishard.com/blog/har-12-spec/#entries) as a parameter and return a boolean indicating whether the entry should be included in the final HAR or not.
+You can specify the `filter` option as a path to a module that exports a function (it can be sync or async) to filter out unwanted entries from the HAR. The function should take an [Entry object](http://www.softwareishard.com/blog/har-12-spec/#entries) as a parameter and return a boolean indicating whether the entry should be included in the final HAR or not.
 
 Here's an example of how to use the `filter` option:
 
@@ -242,9 +242,11 @@ export default async (entry: Entry) => {
 };
 ```
 
+> ✴ The plugin also supports files with `.js`, `.mjs` and `.cjs` extensions.
+
 In this example, the `filter` function will only exclude entries in the HAR where the request body contains a JSON object with a password field.
 
-You can also specify a `rootDir` option that will be used to resolve the path of the `filter` option. By default, the path is relative to the spec folder. But by providing a `rootDir` it will look for the module in the provided directory:
+By default, the path is relative to the spec folder. But by providing a `rootDir` it will look for the module in the provided directory:
 
 ```js
 cy.recordHar({

cypress/e2e/record-har.cy.ts

@@ -21,37 +21,23 @@ describe('Record HAR', () => {
       });
   });
 
-  it('excludes a request using the custom filter from .ts file', () => {
-    cy.recordHar({ filter: '../support/ts-filter.ts' });
+  ['.js', '.mjs', '.ts', '.cjs'].forEach(ext =>
+    it.only(`excludes a request using the custom filter from ${ext} file`, () => {
+      cy.recordHar({ filter: `../support/filter${ext}` });
 
-    cy.get('a[href$=fetch]').click();
-
-    cy.saveHar({ waitForIdle: true });
-
-    cy.findHar()
-      .its('log.entries')
-      .should('not.contain.something.like', {
-        response: {
-          content: { text: /\{"products":\[/ }
-        }
-      });
-  });
-
-  it('excludes a request using the custom filter from .js file', () => {
-    cy.recordHar({ filter: '../support/js-filter.js' });
+      cy.get('a[href$=fetch]').click();
 
-    cy.get('a[href$=fetch]').click();
-
-    cy.saveHar({ waitForIdle: true });
+      cy.saveHar({ waitForIdle: true });
 
-    cy.findHar()
-      .its('log.entries')
-      .should('not.contain.something.like', {
-        response: {
-          content: { text: /\{"products":\[/ }
-        }
-      });
-  });
+      cy.findHar()
+        .its('log.entries')
+        .should('not.contain.something.like', {
+          response: {
+            content: { text: /\{"products":\[/ }
+          }
+        });
+    })
+  );
 
   it('excludes a request by its path', () => {
     cy.recordHar({ excludePaths: ['^\\/api\\/products$', '^\\/api\\/users$'] });

cypress/support/filter.js

@@ -0,0 +1,7 @@
+module.exports = async req => {
+  try {
+    return /\{"products":\[/.test(req.response.content.text ?? '');
+  } catch {
+    return false;
+  }
+};

cypress/support/filter.mjs

@@ -0,0 +1,7 @@
+export default async req => {
+  try {
+    return /\{"products":\[/.test(req.response.content.text ?? '');
+  } catch {
+    return false;
+  }
+};

src/network/DefaultHarExporterFactory.spec.ts

@@ -55,7 +55,7 @@ describe('DefaultHarExporterFactory', () => {
       when(fileManagerMock.createTmpWriteStream()).thenResolve(
         resolvableInstance(writeStreamMock)
       );
-      when(loaderSpy.load('/root/predicate.js')).thenReturn(predicate);
+      when(loaderSpy.load('/root/predicate.js')).thenResolve(predicate);
 
       // act
       const result = await factory.create(options);

src/network/DefaultHarExporterFactory.ts

@@ -20,7 +20,7 @@ export class DefaultHarExporterFactory implements HarExporterFactory {
 
     if (predicatePath) {
       const absolutePath = resolve(rootDir, predicatePath);
-      predicate = Loader.load(absolutePath);
+      predicate = await Loader.load(absolutePath);
     }
 
     return new DefaultHarExporter(

src/utils/Loader.spec.ts

@@ -11,7 +11,7 @@ describe('Loader', () => {
   });
 
   describe('load', () => {
-    it('should load the module from the given path using the default export', () => {
+    it('should load the module from the given path using the default export', async () => {
       // arrange
       jest.mock(
         modulePath,
@@ -21,18 +21,38 @@ describe('Loader', () => {
       );
 
       // act
-      const result = Loader.load<string>(modulePath);
+      const result = await Loader.load<string>(modulePath);
 
       // assert
       expect(result).toBe(module);
     });
 
-    it('should load the module from the given path using the default module.exports', () => {
+    it('should load the es module from the given path', async () => {
+      // arrange
+      jest.mock(
+        modulePath,
+        jest
+          .fn<() => string>()
+          .mockImplementationOnce(() => {
+            throw new Error('[ERR_REQUIRE_ESM]');
+          })
+          .mockReturnValue(module),
+        { virtual: true }
+      );
+
+      // act
+      const result = await Loader.load<string>(modulePath);
+
+      // assert
+      expect(result).toBe(module);
+    });
+
+    it('should load the module from the given path using the default module.exports', async () => {
       // arrange
       jest.mock(modulePath, () => module, { virtual: true });
 
       // act
-      const result = Loader.load<string>(modulePath);
+      const result = await Loader.load<string>(modulePath);
 
       // assert
       expect(result).toBe(module);

src/utils/Loader.ts

@@ -1,17 +1,31 @@
+import { ErrorUtils } from './ErrorUtils';
+
 export class Loader {
-  public static load<T>(path: string): T | undefined {
-    const module = this.interopRequireDefault(
-      // eslint-disable-next-line @typescript-eslint/no-var-requires -- `ts-node` does not handle the dynamic imports like `import(path)`
-      require(/* webpackIgnore: true */ path)
-    );
+  public static async load<T>(path: string): Promise<T | undefined> {
+    let module: unknown;
+
+    try {
+      module = require(/* webpackIgnore: true */ path);
+    } catch (err) {
+      const stack = ErrorUtils.isError(err) ? err.stack : undefined;
+
+      if (
+        !stack?.includes('[ERR_REQUIRE_ESM]') &&
+        !stack?.includes(
+          'SyntaxError: Cannot use import statement outside a module'
+        )
+      ) {
+        throw err;
+      }
+
+      module = (await import(/* webpackIgnore: true */ path)).default;
+    }
 
-    return module?.default as T | undefined;
+    return this.interopRequireDefault<T | undefined>(module);
   }
 
-  private static interopRequireDefault(obj: unknown): {
-    default: unknown;
-  } {
+  private static interopRequireDefault<T>(m: unknown): T | undefined {
     // @ts-expect-error unknown is not assignable to the module type
-    return obj?.__esModule ? obj : { default: obj };
+    return m && m.__esModule && m.default ? m.default : m;
   }
 }