Improve diagnostics for invalid proto files

[pubudu91]

When the proto file is invalid, the grpc command crashes. It would be better if we can have proper error messages for the failures.

For example, in my case, the issue was I hadn't defined a type that I had used in another type:

message PaginatedUser {
    int64 count = 1;
    repeated User list = 2;
    Pagination pagination = 3;
}

The User wasn't defined in the file. The output from the grpc command was as follows:

bal grpc --input resources/user_service.proto
Downloading the protoc executor file - protoc-3.21.7-osx-x86_64.exe
Download successfully completed. Executor file path - /var/folders/_w/76qx789d5hj633snw3c8fswr0000gp/T/protoc-3.21.7-osx-x86_64.exe
Successfully extracted the library files.
Jul 12, 2023 11:27:00 AM io.ballerina.protoc.protobuf.cmd.GrpcCmd generateBalFile
SEVERE: An error occurred when generating the proto descriptor.
io.ballerina.protoc.protobuf.exception.CodeGeneratorException: Invalid command syntax. Stream closed
	at io.ballerina.protoc.protobuf.utils.BalFileGenerationUtils.handleProcessExecutionErrors(BalFileGenerationUtils.java:110)
	at io.ballerina.protoc.protobuf.utils.BalFileGenerationUtils.generateDescriptor(BalFileGenerationUtils.java:83)
	at io.ballerina.protoc.protobuf.cmd.DescriptorsGenerator.generateRootDescriptor(DescriptorsGenerator.java:148)
	at io.ballerina.protoc.protobuf.cmd.GrpcCmd.generateBalFile(GrpcCmd.java:251)
	at io.ballerina.protoc.protobuf.cmd.GrpcCmd.execute(GrpcCmd.java:165)
	at java.base/java.util.Optional.ifPresent(Optional.java:183)
	at io.ballerina.cli.launcher.Main.main(Main.java:53)
Caused by: java.io.IOException: Stream closed
	at java.base/java.io.BufferedInputStream.getBufIfOpen(BufferedInputStream.java:176)
	at java.base/java.io.BufferedInputStream.read(BufferedInputStream.java:342)
	at java.base/sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)
	at java.base/sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)
	at java.base/sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
	at java.base/java.io.InputStreamReader.read(InputStreamReader.java:181)
	at java.base/java.io.BufferedReader.fill(BufferedReader.java:161)
	at java.base/java.io.BufferedReader.readLine(BufferedReader.java:326)
	at java.base/java.io.BufferedReader.readLine(BufferedReader.java:392)
	at io.ballerina.protoc.protobuf.utils.BalFileGenerationUtils.handleProcessExecutionErrors(BalFileGenerationUtils.java:105)
	... 6 more

An error occurred when generating the proto descriptor. Invalid command syntax. Stream closed

This has 2 problems:

• The grpc command has crashed. This is not a good look to have the runtime crash.
• No explanation for the failure. Only says invalid command syntax.

[Abhi132004]

Hii ballerina team , I would like to work on this task

[Abhi132004]

done with the task kindly check.

[ThisaruGuruge]

Hi @Abhi132004! 🚀

We value your contributions and look forward to collaborating with you.
To help you get started, here are some essential resources:

• Understanding Ballerina Platform: Learn what Ballerina is all about: Ballerina Platform
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Remember, no contribution is too small, and your feedback is invaluable. Feel free to ask questions, propose ideas, or report issues. Together, we can make Ballerina even better!

Happy coding! 🎉

[ThisaruGuruge]

done with the task kindly check.

Hi @Abhi132004

You have to do the fix and send a PR to the ballerina-platform organization repository. Please look into the resources provided before working on the issue. Feel free to ask any questions you have regarding this issue.