test: unitest for cortex cpp

[nguyenhoangthuan99]

We need create unitest for done ticket. For now we will use Gtest to write unitest

Unitest can run locally and add to CI pipeline When building debug mode will include test, release wont including it Subtask:

• [x] Cmake build test option
• [ ] CI build and run unitest (Need dev ops)
• [ ] Unitest for utils folder
• [ ] Unitest for commands
• [ ] Unitest for sever service
  • [ ] models services
    • [ ] model pull
    • [ ] model start
    • [ ] model stop
    • [ ] model list
    • [ ] model get
  • [ ] engines services
    • [ ] engine install
    • [ ] engine list
    • [ ] engine get
  • [ ] chat services
    • [ ] stream chat
    • [ ] non stream chat
• [ ] Unitest for engines
  • [ ] llamacpp
  • [ ] tensorrt-llm
  • [ ] onnx

[nguyenhoangthuan99]

Update:

• under development in this branch https://github.com/janhq/cortex/tree/feat-background-process-server/engine/test
• when build add an option to decide build test or not: cmake .. -DCMAKE_BUILD_TEST=ON source code here. Default is OFF -> no build test