Are pysa users expected to copy configuration files?

Question

Facebook's Pysa tool looks useful, in the Pysa tutorial exercises they refer to files that are provided in the pyre-check repository using a relative path to include a path outside of the exercise directory.

https://github.com/facebook/pyre-check/blob/master/pysa_tutorial/exercise1/.pyre_configuration

{
    "source_directories": ["."],
    "taint_models_path": ["."],
    "search_path": [
        "../../stubs/"
    ],
    "exclude": [
        ".*/integration_test/.*"
    ]
}

There are stubs provided for Django in the pyre-check repository which if I know the path where pyre check is installed I can hard-code in my .pyre_configuration and get something working but another developer may install pyre-check differently.

Is there a better way to refer to these provided stubs or should I copy them to the repository I'm working on?

Answer 1

Many projects have a standard development environment, allowing for hard coded paths in the .pyre_configuration file. These will usually point into the venv, or some other standard install location for dependencies.

For projects without a standard development environment, you could trying incorporating pyre init into your setup scripts. pyre init will setup a fresh .pyre_configuration file with paths that correspond to the current install of pyre. For additional configuration you want to add on top of the generated .pyre_configuration file (such as a pointer to local taint models), you can hand write a .pyre_configuration.local, which will act as an overlay and overwrite/add to the content of .pyre_configuration.

Answer 2

Pyre-check looks for the stubs in the directory specified by the typeshed directive in the configuration file.

The easiest way is to move stubs provided for Django in the pyre-check repository to the typeshed directory that is in the pyre-check directory.

For example, if you have installed pyre-check to the ~/.local/lib directory, move the django directory from ~/.local/lib/pyre_check/stubs to ~/.local/lib/pyre_check/typeshed/third_party/2and3/ and make sure your .pyre_configuration file will look like this:

{
  "source_directories": ["~/myproject"],
  "taint_models_path": "~/myproject/taint",
  "typeshed": "~/.local/lib/pyre_check/typeshed"
}

In this case, your Django stubs directory will be ~/.local/lib/pyre_check/typeshed/third_parth/2and3/django

Pyre-check uses the following algorithm to traverse across the typeshed directory:

1. If it contains the third_party subdirectory, it uses a legacy method: enters just the two subdirectories: stdlib and third_party and there looks for any subdirectory except those with names starting with 2 but not 2and3, and looks for the modules in those subdirectories like 2and3, e.g. in third_party/2and3/
2. Otherwise, it enters the subdirectories stubs and stdlib, and looks for modules there, e.g. in stubs/, but not in stubs/2and3/.

That's why specifying multiple paths may be perplexing and confusing, and the easiest way is to setup the typeshed directory to ~/.local/lib/pyre_check/typeshed/ and move django to third_parth/2and3, so it will be ~/.local/lib/pyre_check/typeshed/third_parth/2and3/django.

Also don't forget to copy the .pysa files that you need to the taint_models_path directory. Don't set it up to the directory of the Pyre-check, create your own new directory and copy only those files that are relevant to you.