ImageCompressionFlutter.dummyCallNativeCode shouldn't be able to return null

[zmuranaka]

image_compression_flutter/lib/src/interface.dart

Lines 13 to 30 in fb9880f

	@protected
	Future dummyCallNativeCode(
	String method,
	Map<String, dynamic> data,
	Future<ic.ImageFile> Function() callback,
	) async {
	try {
	// Invoke will work only on Web, otherwise it will execute callback
	final result = await _channel.invokeMethod(method, data);
	if (result is Map) {
	return ImageFileExtension.decode(result);
	}
	return null;
	} on MissingPluginException catch (_) {
	return await callback();
	}
	}

This method should not return null. It currently returns null if result is not a Map, but none of the other places that use this method expect null and will unexpectedly throw if they receive null.

Here is a list of all the places that call dummyCallNativeCode but do not handle receiving null:

image_compression_flutter/lib/src/compressor_io.dart

Line 18 in fb9880f

return await dummyCallNativeCode(

image_compression_flutter/lib/src/compressor_io.dart

Line 36 in fb9880f

return await dummyCallNativeCode(

image_compression_flutter/lib/src/compressor_io.dart

Line 54 in fb9880f

return await dummyCallNativeCode(

image_compression_flutter/lib/src/compressor_io.dart

Line 74 in fb9880f

return await dummyCallNativeCode(

image_compression_flutter/lib/src/interface.dart

Line 34 in fb9880f

return await dummyCallNativeCode(