🐛 Copy the result data instead of referencing directly

[AlexV525]

When a const map was delivered in the call result, modifying the data would be unsupported since the data is unmodifiable.

iris_method_channel_flutter/lib/src/platform/io/iris_method_channel_internal_io.dart

Line 374 in 418b5d4

result.data['observerIntPtr'] = IrisEventHandlerHandle(eventHandlerIntPtr);

The above line might throw:

Unhandled Exception: Unsupported operation: Cannot modify unmodifiable map

[AlexV525]

cc @littleGnAl

[littleGnAl]

Thanks @AlexV525, I'm no longer working for Agora. I think the new maintainer will take a look at your PR.
BTW, I'm not sure if you encountered any issues, but I think this error might not occur based on the current implementation.

[AlexV525]

BTW, I'm not sure if you encountered any issues, but I think this error might not occur based on the current implementation.

For maintainers: the error will occur when an unexpected Agora exception is thrown and the native api result is an empty map.

[littleGnAl]

I think this is an error that could theoretically occur, but has not actually happened, right?

The data is returned here:

iris_method_channel_flutter/lib/src/platform/io/iris_method_channel_internal_io.dart

Line 277 in 418b5d4

return CallApiResult(irisReturnCode: irisReturnCode, data: const {});

iris_method_channel_flutter/lib/src/platform/io/iris_method_channel_internal_io.dart

Line 291 in 418b5d4

return CallApiResult(irisReturnCode: -1, data: const {});

I would personally suggest the following fixes:

1. Not to return a const map for these cases rather than make a copy for the data.
2. The CallApiResult should be designed as an immutable class, rather than assign the new value to the map directly, it's better to make a copy of the result , e.g.,

  CallApiResult createNativeEventHandler(IrisMethodCall methodCall) {
        ...
        return CallApiResult(
          irisReturnCode: result.irisReturnCode,
          data: {
            'observerIntPtr': IrisEventHandlerHandle(eventHandlerIntPtr),
            ...result.data
          },
          rawData: result,
        );
  }

Anyway, I think the new maintainer will make a decision about it.

[AlexV525]

I think this is an error that could theoretically occur, but has not actually happened, right?

Unfortunately, this is an exception I've encountered while debugging.

The CallApiResult should be designed as an immutable class, rather than assign the new value to the map directly, it's better to make a copy of the result

It is, an immutable class does not mean it must be a constant class. But we can take another approach.

[AlexV525]

cc @peilinok