iOS Test Runner Plugin Interface

Overview

This directory contains the protobuf, and the generated C++ and Python files. The protobuf defines the gRPC interface for the communication between XCTest and iOS Test Runner (defined in src/ios/build/bots/scripts) in order to support the video recording plugin feature when running EarlGrey tests.

Note: Files ending with pb2_grpc.py and pb2.py are auto-generated and SHOULD NOT be manually edited.

We use the built-in XCTestObservation to notify our iOS Test Runner about different lifecycles of a test case through gRPC connections. The main test lifecycles defined by Apple are:

            testBundleWillStart:
            — — — testSuiteWillStart:
            — — — — — — testCaseWillStart:
            — — — — — — testCase:didRecord:XCTIssue
            — — — — — — testCase:didRecord:XCTExpectedFailure
            — — — — — — testCaseDidFinish:
            — — — testSuite:didRecord:XCTIssue
            — — — testSuite:didRecord:XCTExpectedFailure
            — — — testSuiteDidFinish:
            testBundleDidFinish:

Googlers can find more information in the design doc

Updating Protobuf Files

First, make your changes in the test_plugin_service.proto file. Ensure that your changes are backward compatible. Then follow the below instructions to re-generate the code in both Python and C++

Python Instruction

TODO(crbug.com/40236071): instead of manually generating the python files every time, add support for generating them in the grpc_library gn template so that they are auto-generated during build time

install grpcio-tools by running (you only need to do this once) python -m pip install grpcio-tools
Regenate python code by running python -m grpc_tools.protoc -I. --python_out=. --grpc_python_out=. test_plugin_service.proto

C++ Instruction

No work needs to be done. C++ files are dynamically generated during runtime using the grpc_library template in BUILD.gn.