feat(plugin): make plugin a "no-op" in unsupported browsers

src/Plugin.spec.ts

@@ -193,15 +193,17 @@ describe('Plugin', () => {
       expect(result).not.toContain(expectedArgs);
     });
 
-    it('should throw an error if an unsupported browser family is used', () => {
+    it('should log a warning if an unsupported browser family is used', () => {
       // arrange
       const args = ['--flag1', '--flag2'];
       // act
-      const act = () => plugin.ensureBrowserFlags(firefox, args);
+      plugin.ensureBrowserFlags(firefox, args);
       // assert
-      expect(act).toThrowError(
-        `An unsupported browser family was used: ${firefox.name}`
-      );
+      verify(
+        loggerMock.warn(
+          `HAR recording is not supported in this browser: ${firefox.name}`
+        )
+      ).once();
     });
 
     it('should throw an error when Electron is used and switches are missed', () => {
@@ -236,6 +238,8 @@ describe('Plugin', () => {
     } as SaveOptions;
 
     it('should log an error message when the connection is corrupted', async () => {
+      // arrange
+      plugin.ensureBrowserFlags(chrome, []);
       // act
       await plugin.saveHar(options);
       // assert
@@ -400,6 +404,19 @@ describe('Plugin', () => {
       verify(harExporterMock.end()).once();
       verify(fileManagerMock.removeFile(tempFilePath)).once();
     });
+
+    it('should be a no-op if an unsupported browser family is used', async () => {
+      // arrange
+      plugin.ensureBrowserFlags(firefox, []);
+      await plugin.recordHar({
+        rootDir: '/'
+      });
+
+      // act
+      await plugin.saveHar(options);
+      // assert
+      verify(fileManagerMock.createFolder(options.outDir)).never();
+    });
   });
 
   describe('recordHar', () => {
@@ -493,6 +510,26 @@ describe('Plugin', () => {
       // assert
       verify(harExporterMock.write(request)).never();
     });
+
+    it('should be a no-op if an unsupported browser family is used', async () => {
+      const request = new NetworkRequest(
+        '1',
+        'https://example.com',
+        'https://example.com',
+        '1'
+      );
+      when(harExporterFactoryMock.create(anything())).thenResolve(
+        resolvableInstance(harExporterMock)
+      );
+      when(networkObserverMock.subscribe(anyFunction())).thenCall(callback =>
+        callback(request)
+      );
+      plugin.ensureBrowserFlags(firefox, []);
+      // act
+      await plugin.recordHar(options);
+      // assert
+      verify(harExporterMock.write(request)).never();
+    });
   });
 
   describe('disposeOfHar', () => {
@@ -539,5 +576,17 @@ describe('Plugin', () => {
       // assert
       verify(networkObserverMock.unsubscribe()).never();
     });
+
+    it('should be a no-op if an unsupported browser family is used', async () => {
+      // arrange
+      plugin.ensureBrowserFlags(firefox, []);
+      await plugin.recordHar({
+        rootDir: '/'
+      });
+      // act
+      await plugin.disposeOfHar();
+      // assert
+      verify(harExporterMock.end()).never();
+    });
   });
 });

src/Plugin.ts

@@ -44,6 +44,7 @@ export class Plugin {
   private networkObservable?: Observer<NetworkRequest>;
   private addr?: Addr;
   private _connection?: Connection;
+  private supported?: boolean;
 
   constructor(
     private readonly logger: Logger,
@@ -57,9 +58,10 @@ export class Plugin {
     browser: Cypress.Browser,
     args: string[]
   ): string[] {
-    if (!this.isSupportedBrowser(browser)) {
-      throw new Error(
-        `An unsupported browser family was used: ${browser.name}`
+    this.supported = this.isSupportedBrowser(browser);
+    if (!this.supported) {
+      this.logger.warn(
+        `HAR recording is not supported in this browser: ${browser.name}`
       );
     }
 
@@ -77,14 +79,18 @@ export class Plugin {
   }
 
   public async recordHar(options: RecordOptions): Promise<void> {
-    await this.closeConnection();
-
     if (!this.addr) {
       throw new Error(
         `Please call the 'ensureBrowserFlags' before attempting to start the recording.`
       );
     }
 
+    if (!this.supported) {
+      return;
+    }
+
+    await this.closeConnection();
+
     this.exporter = await this.exporterFactory.create(options);
     this._connection = this.connectionFactory.create({
       ...this.addr,
@@ -99,6 +105,10 @@ export class Plugin {
   }
 
   public async saveHar(options: SaveOptions): Promise<void> {
+    if (!this.supported) {
+      return;
+    }
+
     const filePath = join(options.outDir, options.fileName);
 
     if (!this._connection) {
@@ -130,6 +140,10 @@ export class Plugin {
   }
 
   public async disposeOfHar(): Promise<void> {
+    if (!this.supported) {
+      return;
+    }
+
     await this.networkObservable?.unsubscribe();
     delete this.networkObservable;