Typescript check for FFprobeKit.getMediaInformationAsync

[iclassPeter]

Description
Not functional issue, just typescript check. Typescript not match in argument of getMediaInformationAsync under FFprobeKit.

Expected behavior
The second argument of getMediaInformationAsync is in type ExecuteCallback = (session: Session) => void; but the session return should be MediaInformationSession. probably having same issue on getMediaInformationFromCommandAsync and getMediaInformationFromCommandArgumentsAsync under FFprobeKit.

Current behavior
Argument of type '(session: MediaInformationSession) => Promise' is not assignable to parameter of type 'ExecuteCallback'.
Types of parameters 'session' and 'session' are incompatible.
Type 'Session' is missing the following properties from type 'MediaInformationSession': getMediaInformation, setMediaInformation

To Reproduce

FFprobeKit.getMediaInformationAsync(
                        path, 
                        async (session:MediaInformationSession) => { 
                            const information:MediaInformation = await session.getMediaInformation();
                            const duration = information.getDuration();
                        }
)

Screenshots

Environment

• Platform: React Native
• Version: ^4.5.0 , full-gpl-lts
• Source branch: react native

[tanersener]

ExecuteCallback is used by other API methods as well. And, they don't return MediaInformationSession. For example, some methods return FFmpegSession. If I make this change they will complain. That's why it is defined as generic Session.

I can create separate Callbacks for each method, e.g. MediaInformationSessionCallback, FFprobeSessionCallback, FFmpegSessionCallback. Will that work for you, or will it make it too complicated?

[iclassPeter]

Separate Callbacks types would work. It might actually ease new user calling the api, as correct type helps autofill functions and confirm they are useable. Btw thank you for making this library.

---

P.S. I dont know what could be gone too complicated if changing type as I am new to typescript and sessions actually.

What I gone through without exact correct type:
I didnot know session.getMediaInformation return type MediaInformation from reading doc so I was confused on the [object] returned. I could only see [object] in console.log so I have looked into the declaration to find out what functions i could use.

[tanersener]

We have identical APIs across all platforms. These callback types are the same in all of them. Your problem is also a common one. Other platforms need to cast the session instance to the actual session type in order to call some of the methods, which is not very nice.

I'll mark this as an enhancement request and work on this. Thanks for reporting.

[iclassPeter]

One could use Type Assertions if feeling needed to remove the red underline, but it's not changing the way of finding out the type of session.

FFprobeKit.getMediaInformationAsync(
    path, 
    async (session) => {
        const information = await (session as MediaInformationSession).getMediaInformation();
        const duration = information.getDuration();
    }
);

[tanersener]

Yeah, you can use that if you are developing using TypeScript.

[tanersener]

Fixed in v4.5.1.

[aklemen]

Hi, could you please provide an example for calling FFprobeKit.getMediaInformationAsync() with appropriate types (in React Native)?

I noticed that in the new version v4.5.1 the executeCallback?: ExecuteCallback (which receives generic Session as an argument) has been changed to completeCallback?: FFprobeSessionCompleteCallback (which receives FFProbeSession as an argument). Should the type for FFprobeKit.getMediaInformationAsync()'s completeCallback be MediaInformationSessionCallback (with MediaInformationSession as in @iclassPeter's example)?

[tanersener]

@aklemen ffmpeg-kit-test project includes examples for most of the API methods. We don't have a typescript application yet. But typescript definitions are there, they will help you about the types.

[aklemen]

@tanersener I tried one of the examples before, but it didn't work (got error Typescript: undefined is not a function).
I cleared the npm cache and did a clean install of the RN app and now it works.

I'll leave this simple example (to get duration in seconds) here, if anyone needs it in the future.

FFprobeKit.getMediaInformation(filepath)
  .then(async (session: MediaInformationSession) => {
    const information: MediaInformation = await session.getMediaInformation();
    const durationInSeconds: number = information.getDuration();
  })
  .catch(error => console.error(error));

Thank you!