subscribe (Observer) の onError 各種 Operator よりまず subscribe (Observer) の onError です。Observable.throw でエラーを流してみましょう。 import { Observable } from 'rx'; Observable .throw(new Error('ERROR!!')) .subscribe( value => console.log(`onNext: ${value}`), error => console.log(`onError: ${error}`), () => console.log('onCompleted') ); // onError: Error: ERROR!! import { Observable } from 'rx'; Observable .from([1,
![RxJS の Operators (6) - Observable のエラーハンドリング - Qiita](https://cdn-ak-scissors.b.st-hatena.com/image/square/39810eeea3e2e9b7e02a315ad94b7deffc6a7b63/height=288;version=1;width=512/https%3A%2F%2Fqiita-user-contents.imgix.net%2Fhttps%253A%252F%252Fcdn.qiita.com%252Fassets%252Fpublic%252Fadvent-calendar-ogp-background-7940cd1c8db80a7ec40711d90f43539e.jpg%3Fixlib%3Drb-4.0.0%26w%3D1200%26mark64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZ3PTk3MiZoPTM3OCZ0eHQ9UnhKUyUyMCVFMyU4MSVBRSUyME9wZXJhdG9ycyUyMCUyODYlMjklMjAtJTIwT2JzZXJ2YWJsZSUyMCVFMyU4MSVBRSVFMyU4MiVBOCVFMyU4MyVBOSVFMyU4MyVCQyVFMyU4MyU4RiVFMyU4MyVCMyVFMyU4MyU4OSVFMyU4MyVBQSVFMyU4MyVCMyVFMyU4MiVCMCZ0eHQtYWxpZ249bGVmdCUyQ3RvcCZ0eHQtY29sb3I9JTIzM0EzQzNDJnR4dC1mb250PUhpcmFnaW5vJTIwU2FucyUyMFc2JnR4dC1zaXplPTU2JnM9YWI0MjBiOTY3ZTQzNmIyMjNmMzYwNjFmZjdkMTMyMTI%26mark-x%3D120%26mark-y%3D96%26blend64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZoPTc2Jnc9OTcyJnR4dD0lNDBib3V6dXlhJnR4dC1jb2xvcj0lMjMzQTNDM0MmdHh0LWZvbnQ9SGlyYWdpbm8lMjBTYW5zJTIwVzYmdHh0LXNpemU9MzYmdHh0LWFsaWduPWxlZnQlMkN0b3Amcz1lM2U5YTAxOTM4NDI3MTczZDMyNDhmNGYxMzY1NjU4MA%26blend-x%3D120%26blend-y%3D500%26blend-mode%3Dnormal%26s%3D50c0dc41f9ccd8080c9b4e1349d05c8c)