### Set up a Python Project and Virtual Environment

Source: https://pyre-check.org/docs/getting-started

Creates a new project directory, sets up a Python virtual environment, activates it, and installs the pyre-check package.

```Shell
mkdir my_project && cd my_project
python3 -m venv ~/.venvs/venv
source ~/.venvs/venv/bin/activate
pip install pyre-check
```

--------------------------------

### Install Watchman and Python (Ubuntu/Debian)

Source: https://pyre-check.org/docs/getting-started

Installs Python 3, pip, venv, and Watchman using apt-get on Ubuntu, Mint, or Debian systems.

```Shell
sudo apt-get install python3 python3-pip python3-venv watchman
```

--------------------------------

### Install Wheel and Setuptools Packages

Source: https://pyre-check.org/docs/pysa-quickstart

Installs the 'wheel' and upgrades 'setuptools' to resolve 'invalid command bdist_wheel' errors during installation.

```bash
(pysa) $ pip3 install wheel
(pysa) $ python3.8 -m pip install --upgrade setuptools
```

--------------------------------

### Pyre Check Output Example

Source: https://pyre-check.org/docs/installation

This shows example output from the 'pyre check' command, indicating successful setup and no type errors found.

```Shell
(tp) cooper@TESTFAC-1FMHLI2:/mnt/c/path/to/repo$ pyre --source-directory . check
 ƛ Setting up a `.pyre_configuration` with `pyre init` may reduce overhead.  
 ƛ No type errors found
```

--------------------------------

### Install Python Development Headers and Setuptools

Source: https://pyre-check.org/docs/pysa-quickstart

Installs necessary development headers for Python and upgrades setuptools to resolve compilation errors during package installation.

```bash
$ sudo apt install python3.8-dev -y
$ source ~/.venvs/pysa/bin/activate
$ (pysa) python3.8 -m pip install --upgrade setuptools
```

--------------------------------

### Install Watchman and Python (macOS)

Source: https://pyre-check.org/docs/getting-started

Installs Python 3 and Watchman using Homebrew on macOS, which are prerequisites for using Pyre.

```Shell
brew install python3 watchman
```

--------------------------------

### Start SAPP Server

Source: https://pyre-check.org/docs/pysa-quickstart

Spawns the SAPP web server, making the analysis results accessible via a web UI at http://localhost:5000.

```Bash
(pysa) $ sapp server
```

--------------------------------

### Install Pyre and SAPP

Source: https://pyre-check.org/docs/pysa-quickstart

Installs the pyre-check and fb-sapp Python packages within the activated virtual environment using pip.

```Bash
(pysa) $ pip install pyre-check fb-sapp
```

--------------------------------

### Install Python Packages

Source: https://pyre-check.org/docs/pysa-quickstart

Installs or upgrades the setuptools and wheel Python packages using pip. These are required dependencies for Pyre and Pysa.

```Bash
$ python3.8 -m pip install --upgrade setuptools
$ pip3 install wheel
```

--------------------------------

### Initialize Pyre Configuration

Source: https://pyre-check.org/docs/getting-started

Initializes Pyre in the current project directory, creating the necessary configuration files (.pyre_configuration and .watchmanconfig).

```Shell
pyre init
```

--------------------------------

### Setup Pyre-check Development Environment

Source: https://pyre-check.org/docs/installation

Sets up the local development environment for Pyre-check, including compiling the binary and running unit tests. This script is part of the build-from-source process.

```bash
$ cd pyre-check
$ ./scripts/setup.sh --local
```

--------------------------------

### Install Python Client Dependencies and Run Tests

Source: https://pyre-check.org/docs/installation

Installs the necessary dependencies for the Python client from a requirements file and executes the Python tests. This is used to verify the setup for testing Python client changes.

```bash
$ cd /path/to/pyre-check
$ pip install -r requirements.txt
$ ./scripts/run-python-tests.sh
```

--------------------------------

### Install pyre-check in Virtual Environment

Source: https://pyre-check.org/docs/pysa-quickstart

Ensures pyre-check is installed within the activated virtual environment to avoid permission errors.

```bash
$ source ~/.venvs/pysa/bin/activate
(pysa) $ pip install pyre-check
```

--------------------------------

### Initialize Pysa and SAPP

Source: https://pyre-check.org/docs/pysa-quickstart

Initializes Pysa and SAPP for the current project, setting up the necessary environment and configuration for Pysa analysis.

```Bash
(pysa) $ pyre init-pysa
```

--------------------------------

### Set Up Virtual Environment

Source: https://pyre-check.org/docs/pysa-quickstart

Creates a Python virtual environment named 'pysa' in the user's home directory and activates it for isolated package management.

```Bash
$ python3.8 -m venv ~/.venvs/pysa
$ source ~/.venvs/pysa/bin/activate
```

--------------------------------

### Install Pyre-check (Non-Nightly)

Source: https://pyre-check.org/docs/pysa-quickstart

If Pysa is not working, ensure you are not using a nightly version of Pyre. Uninstall `pyre-check-nightly` and install the stable `pyre-check` package.

```Shell
(pysa) $ pip uninstall pyre-check-nightly
(pysa) $ pip install pyre-check
```

--------------------------------

### Update Python on Ubuntu

Source: https://pyre-check.org/docs/pysa-quickstart

Updates the system package list and installs Python 3.8, its virtual environment package, development headers, and pip on Ubuntu systems.

```Bash
$ sudo apt-get update
$ sudo apt install python3.8 python3.8-venv python3.8-dev python3-pip -y
```

--------------------------------

### Example Pyre Configuration Structure

Source: https://pyre-check.org/docs/configuration

An example of the .pyre_configuration JSON file. It specifies source directories and search paths for Pyre to analyze Python code and external libraries.

```JSON
{
  "source_directories": [
    "."
  ],
  "search_path": [
    "/external/library",
    {"site-package": "foo"}
  ]
}
```

--------------------------------

### Create Virtual Environment with Python 3.8

Source: https://pyre-check.org/docs/pysa-quickstart

Creates a virtual environment for Pysa using Python 3.8, ensuring the 'ensurepip' module is available.

```bash
$ sudo apt install python3.8-venv python3.8-dev -y
$ rm -rf ~/.venvs/pysa
$ python3.8 -m venv ~/.venvs/pysa
```

--------------------------------

### Install Pyre-check on Ubuntu with venv

Source: https://pyre-check.org/docs/installation

This sequence of commands demonstrates setting up a Python virtual environment on Ubuntu, installing pyre-check using pip, and activating the environment.

```Bash
$ sudo apt install python3-venv build-essential python3-dev libpython3-dev
$ python3 -m venv /tmp/tp
$ /tmp/tp/bin/pip install --upgrade pip setuptools wheel
$ /tmp/tp/bin/pip install pyre-check
$ source /tmp/tp/bin/activate
```

--------------------------------

### Configure Pyre for External Libraries

Source: https://pyre-check.org/docs/pysa-quickstart

Add the path to an external library to your `.pyre_configuration` if it wasn't installed with pip and is being used via `module.path.function_name`.

```JSON
{
  "source_directories": [
    "."
  ],
  "search_path": [
    "path/to/external/library"
  ],
  "taint_models_path": "~/.venvs/pysa/lib"
}
```

--------------------------------

### Run Pyre Type Checker

Source: https://pyre-check.org/docs/getting-started

Creates a Python file with a type error and then runs Pyre to detect and report the type checking issues.

```Shell
echo "i: int = 'string'" > test.py
pyre
```

--------------------------------

### Clone Pyre-check Repository

Source: https://pyre-check.org/docs/installation

Clones the Pyre-check source code repository from GitHub. This is the first step for building from source.

```bash
$ git clone https://github.com/facebook/pyre-check
```

--------------------------------

### Run Pysa Analysis

Source: https://pyre-check.org/docs/pysa-quickstart

Executes Pysa analysis on the project without verification and saves the results to a specified directory './pysa-runs'.

```Bash
(pysa) $ pyre analyze --no-verify --save-results-to ./pysa-runs
```

--------------------------------

### Analyze Project with SAPP

Source: https://pyre-check.org/docs/pysa-quickstart

Run the `sapp analyze` command to import issues and traces into SAPP. This output indicates if the analysis is proceeding correctly.

```Shell
(pysa) $ sapp analyze
```

--------------------------------

### Pyre Command Line Examples

Source: https://pyre-check.org/docs/configuration

Demonstrates how to run Pyre commands with common flags, such as specifying the source directory and running in non-interactive mode.

```bash
$ pyre --source-directory "." --noninteractive check  
$ pyre --source-directory "." restart  
```

--------------------------------

### Install Pyre-check via Pip

Source: https://pyre-check.org/docs/installation

Installs the Pyre-check tool using pip within a virtual environment. This is the recommended method for macOS and Linux users.

```bash
(venv) $ pip install pyre-check
```

--------------------------------

### Python Source Summary Example

Source: https://pyre-check.org/docs/pysa-implementation-details

Demonstrates how Pysa infers a source summary for a function that returns tainted data. It starts with a model for a 'source' function and shows how Pysa analyzes 'returns_source' and 'wraps_source' to infer their respective source summaries.

```Python
def source() -> TaintSource[UserControlled]: ...
```

```Python
def returns_source():  
  return source()  
```

```Python
def returns_source() -> TaintSource[UserControlled]: ...
```

```Python
def wraps_source():  
  return returns_source()  
```

```Python
def wraps_source() -> TaintSource[UserControlled]  
```

--------------------------------

### Recreate Virtual Environment

Source: https://pyre-check.org/docs/pysa-quickstart

Provides steps to delete and recreate the virtual environment to fix issues related to corrupted type stubs, such as the 'zlib.pyi is not a directory' error.

```bash
(pysa) $ deactivate
$ rm -rf ~/.venvs/pysa
```

--------------------------------

### Clone Pyre-check Repository

Source: https://pyre-check.org/docs/installation

This snippet shows how to clone the pyre-check repository from GitHub and navigate to its root directory using Git.

```Bash
git clone https://github.com/facebook/pyre-check.git
cd pyre-check
```

--------------------------------

### Analyze Pysa Results with SAPP

Source: https://pyre-check.org/docs/pysa-quickstart

Ingests the Pysa analysis results (taint-output.json) into SAPP for further processing and analysis.

```Bash
(pysa) $ sapp analyze ./pysa-runs/taint-output.json
```

--------------------------------

### Start Pyre Server with External Source Analysis

Source: https://pyre-check.org/docs/querying-pyre

Provides commands to stop existing Pyre servers and start a new one with specific flags to ensure external sources are analyzed, which is crucial for accurate Pysa analysis.

```Shell
$ pyre servers stop # Stop existing pyre servers
$ pyre --no-saved-state start --wait-on-initialization --analyze-external-sources
```

--------------------------------

### Resolve Pyre Client Not Found Error

Source: https://pyre-check.org/docs/pysa-quickstart

Demonstrates how to resolve the 'Could not find a pyre client' error by ensuring the pyre executable is in the PATH of the activated virtual environment.

```bash
(pysa) $ pip install pyre-check
(pysa) $ cd demo-project
(pysa) $ pyre analyze --no-verify
ƛ Error: Could not find a pyre client.
(pysa) $ which pyre
/usr/local/bin/pyre
(pysa) $ deactivate
(pysa) $ zsh
$ source ~/.venvs/pysa/bin/activate
(pysa) $ which pyre
/Users/unixname/.venvs/pysa/bin/
```

--------------------------------

### Serve SAPP with Source Directory

Source: https://pyre-check.org/docs/pysa-quickstart

When SAPP Web UI shows 'No file found for filename.py', use the `--source-directory` flag with `sapp server` to provide the path to your project's source code.

```Shell
(pysa) $ sapp server --source-directory path/to/project_source_code
```

--------------------------------

### Initialize Pyre inside Docker Container

Source: https://pyre-check.org/docs/installation

These commands show the manual input required when initializing Pyre inside the Docker container, specifying paths for the pyre binary and typeshed.

```Shell
ƛ No `pyre.bin` found, enter the path manually: /home/opam/pyre-check/source/_build/default/main.exe
ƛ Unable to locate typeshed, please enter its root: /home/opam/pyre-check/stubs/typeshed/typeshed-master
```

--------------------------------

### Run Pyre Check on WSL

Source: https://pyre-check.org/docs/installation

This snippet shows how to navigate to a local repository directory within the activated WSL environment and run the pyre check command.

```Bash
$ cd /mnt/c/path/to/repo
$ pyre --source-directory . check
```

--------------------------------

### Build Pyre-check Docker Image

Source: https://pyre-check.org/docs/installation

This command builds a Docker image with the tag 'pyre-check' from the current directory, which contains the pyre-check source code.

```Shell
docker build -t pyre-docker .
```

--------------------------------

### Check for Pysa Issues in taint-output.json

Source: https://pyre-check.org/docs/pysa-quickstart

Confirm if Pysa has identified any issues in your project by checking the `taint-output.json` file for the presence of the 'issue' keyword.

```Shell
(pysa) $ cat taint-output.json | grep "issue"
```

--------------------------------

### Format String Examples for Cache Keys

Source: https://pyre-check.org/docs/pysa-model-dsl

Provides examples of using format strings with variables like class_name and function_name to construct dynamic cache keys for WriteToCache and CrossRepositoryTaintAnchor clauses.

```Python
WriteToCache(kind="cache_name", name=f"{class_name}:{function_name}")
```

```Python
CrossRepositoryTaintAnchor[TaintSink[Thrift], f"{class_name}:{function_mame}", f"formal({parameter_position + 1})"]
```

--------------------------------

### Compile and Test Pyre-check Changes

Source: https://pyre-check.org/docs/installation

Compiles the Pyre-check source code and runs all unit tests after making code modifications. This is done within the 'source' directory of the cloned repository.

```bash
$ cd source
$ make
$ make test
```

--------------------------------

### Pysa Model Annotation Example

Source: https://pyre-check.org/docs/pysa-tips

Provides an example of how to add taint annotations to stubbed external code, specifically marking HttpRequest.COOKIES and HttpRequest.GET as TaintSource[UserControlled].

```Python
django.http.request.HttpRequest.COOKIES: TaintSource[UserControlled]
django.http.request.HttpRequest.GET: TaintSource[UserControlled]
```

--------------------------------

### Check Python Version for SAPP

Source: https://pyre-check.org/docs/pysa-quickstart

Verify that your Python version is 3.8 or later to resolve `SyntaxError: future feature annotations is not defined` when running `sapp` commands.

```Shell
$ python3 --version
```

--------------------------------

### Python Examples for String Combine Rule

Source: https://pyre-check.org/docs/pysa-advanced

These Python code examples illustrate scenarios where user-controlled data ('uc') flows into strings that are formatted or concatenated, potentially leading to SQL injection. The examples cover f-strings, string concatenation, the '%' operator, and `str.format`, all of which can be detected by the string combine rule.

```Python
def issue():
  uc = user_controlled()
  f"SELECT {uc} FROM async_query"
  "SELECT " + uc + " FROM async_query"
  "SELECT %s FROM async_query" % uc
  "SELECT {} FROM async_query".format(uc)
```

--------------------------------

### Taint Analysis Configuration Options

Source: https://pyre-check.org/docs/pysa-advanced

Provides an example of the `options` section in `taint.config` for setting analysis thresholds. This includes parameters like `maximum_model_source_tree_width`.

```JSON
{
  "sources": [],
  "sinks": [],
  "features": [],
  "rules": [],
  "options": {
    "maximum_model_source_tree_width": 10,
    "maximum_model_sink_tree_width": 10,
    "maximum_model_tito_tree_width": 10
  }
}
```

--------------------------------

### Run Pyre-check Docker Container

Source: https://pyre-check.org/docs/installation

This command runs a new Docker container named 'pyre-container' from the 'pyre-docker' image. It mounts a local directory to '/src' inside the container and runs interactively.

```Shell
docker run \
--name pyre-container \
-v /path/to/your/directory:/src \
-t -i \
pyre-check
```

--------------------------------

### Reactivate Pyre Environment (zsh)

Source: https://pyre-check.org/docs/pysa-quickstart

For shells like zsh, after uninstalling a nightly version, you may need to deactivate the current environment, source the Pyre environment script, and then reinstall the stable version.

```Shell
(pysa) $ pip uninstall pyre-check-nightly
(pysa) $ deactivate
$ zsh
(pysa) $ source ~/.venvs/pysa/bin/activate
(pysa) $ pip install pyre-check
```

--------------------------------

### Run Pysa Analysis

Source: https://pyre-check.org/docs/pysa-explore

This command initiates Pysa's static analysis on your codebase and saves the results to a specified directory. Ensure Pysa is installed and configured for your project.

```Shell
$ pyre analyze --save-results-to /tmp/output_dir
```

--------------------------------

### Model urllib.request.urlopen Signature - Full Match

Source: https://pyre-check.org/docs/pysa-basics

Provides an example of a Pysa model for the `urllib.request.urlopen` function, matching its full signature including keyword-only arguments.

```Python
def urllib.request.urlopen(url: TaintSink[HTTPClientRequest], data, timeout, *, cafile, capath, cadefault, context): ...
```

--------------------------------

### Get Function and Method Definitions with Pyre Query

Source: https://pyre-check.org/docs/querying-pyre

The `defines` command lists all function and method definitions within a given module or class. It returns the name, parameters, and return annotation for each definition.

```shell
$ pyre query "defines(a.C)"
```

```shell
$ pyre query "defines(a)"
```

--------------------------------

### ModelQuery with fully_qualified_name.matches

Source: https://pyre-check.org/docs/pysa-model-dsl

Demonstrates a `ModelQuery` using the `fully_qualified_name.matches` predicate to find entities whose fully qualified names start with 'foo'.

```Python
ModelQuery(
  name = "get_starting_with_foo",
  find = ...,
  where = [
    fully_qualified_name.matches("foo.*")
  ],
  model = ...
)
```

--------------------------------

### Skip Model Validation in Pyre Analyze

Source: https://pyre-check.org/docs/pysa-quickstart

Instructs to use the '--no-verify' flag with 'pyre analyze' to skip model validation and potentially resolve analysis errors.

```bash
$ pyre analyze --no-verify
```

--------------------------------

### Pyre Model Query Example

Source: https://pyre-check.org/docs/querying-pyre

Demonstrates how to use the ModelQuery feature in Pyre to find functions matching specific criteria and apply taint models. It shows the Pyre query syntax and the expected JSON response.

```Python
ModelQuery(
    name = "get_foo_sources",
    find = "functions",
    where = [
        name.matches("foo")
    ],
    model = [
        Parameters(TaintSource[Test])
    ]
)
```

--------------------------------

### Model File Annotations Example

Source: https://pyre-check.org/docs/pysa-basics

Illustrates how annotations are applied in model files (e.g., `.pysa`) to combine inferred models with declared models, allowing multiple annotations for a single property.

```Python
django.http.request.HttpRequest.COOKIES: TaintSource[UserControlled]
django.http.request.HttpRequest.COOKIES: TaintSource[Cookies]
```

--------------------------------

### Class Attribute Example

Source: https://pyre-check.org/docs/pysa-model-dsl

Illustrates how attributes, including constructor-initialized ones like `self.y`, are handled when using the `attributes` find clause.

```Python
class C:
  x = ...

  def __init__(self):
    self.y = ...

```

--------------------------------

### Batch Multiple Pyre Queries

Source: https://pyre-check.org/docs/querying-pyre

This example illustrates how to use the `batch` command to execute multiple Pyre queries simultaneously. It shows a batch query combining `less_or_equal` and `join` operations and the resulting list of responses.

```Shell
$ pyre query "batch(less_or_equal(int, str), join(int, str))"
```

--------------------------------

### Python Stub File Example

Source: https://pyre-check.org/docs/types-in-python

Demonstrates a Python stub file (`.pyi`) with a function signature and a `__getattr__` definition. This shows how Pyre handles partially complete stub files, where undefined attributes are treated as `Any`.

```Python
# my_dynamic_module.pyi
def dynamic_function() -> int: ...
```

```Python
# my_stub.pyi
from typing import Any
foo: int = 42
# Parameter needs to be typed as `str` and return type needs to be `Any`
def __getattr__(name: str) -> Any: ...
```

```Python
# my_source.py
import my_stub
reveal_type(my_stub.foo)        # Reveals `int`
reveal_type(my_stub.undefined)  # Reveals `Any`
```

--------------------------------

### Query Types in a Python File

Source: https://pyre-check.org/docs/querying-pyre

This example demonstrates how to query the types of expressions within a Python file using Pyre. It shows the command to execute and the expected JSON output detailing the types and their locations.

```Shell
$ pyre query "types(path='a.py')"
```

--------------------------------

### Python Source Code for Pysa Analysis

Source: https://pyre-check.org/docs/pysa-running

This Python code defines functions to get an image from a URL and convert it, demonstrating user input as a taint source and os.system as a taint sink.

```Python
# static_analysis_example/source.py  
  
import os  
  
def get_image(url):
    command = "wget -q https:{}".format(url)
    return os.system(command)
  
def convert():
    image_link = input("image link: ")
    image = get_image(image_link)

```

--------------------------------

### Evaluate Expression Type using Pyre Query

Source: https://pyre-check.org/docs/querying-pyre

Demonstrates the `type` Pyre query command, which evaluates and returns the type of a given expression. Includes an example query for a list containing an integer and an empty string.

```Shell
$ pyre query "type([1 + 2, ''])"
```

--------------------------------

### Pysa Feature Annotation Non-Contagious Example

Source: https://pyre-check.org/docs/pysa-advanced

This example demonstrates that `@AddFeatureToState` is not contagious. The feature is not propagated when `security_check` is called via a wrapper function.

```Python
def security_check_wrapper():
  return security_check()

x = some_source()
if security_check_wrapper():
    some_sink(x)
```

--------------------------------

### Pysa Sanitizer Example

Source: https://pyre-check.org/docs/pysa-advanced

This example demonstrates the use of a Pysa sanitizer to prevent taint propagation. The `@Sanitize` decorator marks a function as a sanitizer for a specific taint type.

```Python
@Sanitize(TaintInTaintOut[TaintSink[RemoteCodeExecution]])
def shlex.quote(x): ...
```

--------------------------------

### Pysa Feature Annotation Example

Source: https://pyre-check.org/docs/pysa-advanced

This example shows how `@AddFeatureToState` annotates data flow. When `security_check()` is called, the `via:security_check` feature is added to local variables, enabling filtering.

```Python
x = some_source()
if security_check():
    some_sink(x)
```

--------------------------------

### Pysa Call Graph Filtering Example

Source: https://pyre-check.org/docs/pysa-advanced

This example illustrates how Pysa's `@Entrypoint` decorator filters the call graph. Only functions called directly or indirectly by an entrypoint are analyzed.

```Python
@Entrypoint
def my_file.MyClass.class_entrypoint(): ...

@Entrypoint
def func_entrypoint(): ...
```

--------------------------------

### Sanitize HttpRequest GET Attribute

Source: https://pyre-check.org/docs/pysa-basics

This Python code demonstrates sanitizing the 'GET' attribute of an `HttpRequest` object. The `Sanitize` annotation indicates that all taint passing through `HttpRequest.GET` will be removed.

```Python
django.http.request.HttpRequest.GET: Sanitize
```

--------------------------------

### Model Django HttpRequest GET Taint Source

Source: https://pyre-check.org/docs/pysa-basics

Demonstrates how to specify a taint source for the 'GET' attribute of Django's HttpRequest object using its fully qualified name.

```Python
django.http.request.HttpRequest.GET: TaintSource[UserControlled]
```

--------------------------------

### Pysa Issue Broadening Example

Source: https://pyre-check.org/docs/pysa-advanced

Demonstrates how Pysa flags issues even when only a part of an object is tainted. In this example, a dictionary `d` has one tainted key-value pair, and Pysa correctly identifies this as a valid flow to the sink.

```Python
d = {"a": source(), "b": "foo"}  
sink(d) # `d` itself is not tainted, but `d["a"]` is, thus we emit an issue.
```

--------------------------------

### Configure Pyre Command Alias and Binary Path

Source: https://pyre-check.org/docs/installation

Sets up bash aliases and environment variables to run the Pyre command from anywhere and point to the compiled binary. This is crucial for making the 'pyre' command accessible after building from source.

```bash
$ echo "alias pyre='PYTHONPATH="/path/to/pyre-check/..:$PYTHONPATH" python -m pyre_check.client.pyre'" >> ~/.bashrc
$ echo "export PYRE_BINARY=/path/to/pyre-check/source/_build/default/main.exe" >> ~/.bashrc
$ source ~/.bashrc
```

--------------------------------

### Python Tito Propagation Example

Source: https://pyre-check.org/docs/pysa-advanced

Illustrates a 'Taint In Taint Out' (TITO) scenario in Python where taint propagates through multiple function calls. This example demonstrates how Pysa might track taint through chained function calls like `baz` calling `bar` which calls `foo`.

```python
def foo(x):
  return x
def bar(x):
  return foo(x)
def baz(x):
  return bar(x)
```

--------------------------------

### Create Executable Script for VSCode Plugin Development

Source: https://pyre-check.org/docs/installation

Creates a bash script to act as the 'pyre' executable for VSCode plugin development. This bypasses shell aliases, allowing VSCode to find the correct Pyre client.

```bash
#!/bin/bash
PYTHONPATH="/path/to/pyre-check/..:$PYTHONPATH" python -m pyre_check.client.pyre "$@"
```

--------------------------------

### Initialize Pyre Configuration

Source: https://pyre-check.org/docs/configuration

Command to generate an initial Pyre configuration file in the project directory. This sets up the basic structure for Pyre's type checking.

```Shell
pyre init
```

--------------------------------

### Save Pyre Server State

Source: https://pyre-check.org/docs/querying-pyre

Illustrates how to save the current state of a Pyre server for later use and how to load it to start a new server without re-analyzing project files. Includes commands for saving, stopping, and loading.

```Shell
$ pyre query "save_server_state('my_saved_state')"
$ pyre stop
$ pyre --load-initial-state-from my_saved_state start
```

--------------------------------

### Get Issues for a Callable

Source: https://pyre-check.org/docs/pysa-explore

Retrieves all security issues associated with a specific callable. This function returns a list of issue objects.

```Python
>>> get_issues('foo.bar.log_errors')
```

--------------------------------

### Execute Pyre Query

Source: https://pyre-check.org/docs/querying-pyre

Shows how to execute a Pyre query from the command line, specifically querying for a model defined by 'get_foo_sources' within a specified directory. Includes the command and its JSON output.

```Shell
$ pyre query "model_query(path='/absolute/path/to/test_pysa/directory', query_name='get_foo_sources')"
```

--------------------------------

### Pyre Error: Unexpected Keyword Argument

Source: https://pyre-check.org/docs/errors

Shows an example of Pyre flagging an unexpected keyword argument passed during a function call.

```Python
def foo(integer: int, string: str) -> None: ...

foo(1, "one")  # no error
foo(string="one", integer=1)  # no error
foo(integer=1, undefined="one")  # type error
```

--------------------------------

### Python Sink Summary Example

Source: https://pyre-check.org/docs/pysa-implementation-details

Illustrates Pysa's inference of sink summaries, tracking how function arguments flow into sinks. It shows an initial model for a 'sink' function and how Pysa analyzes 'calls_sink' and 'wraps_sink' to infer their sink summaries.

```Python
def sink(arg: TaintSink[RemoteCodeExecution]): ...
```

```Python
def calls_sink(arg):  
  sink(arg)  
```

```Python
def calls_sink(arg: TaintSink[RemoteCodeExecution]): ...
```

```Python
def wraps_sink(arg):  
  calls_sink(arg)  
```

```Python
def wraps_sink(arg: TaintSink[RemoteCodeExecution]): ...
```

--------------------------------

### Start Pysa Model Explorer

Source: https://pyre-check.org/docs/pysa-explore

Launches the interactive Pysa Model Explorer script. This script requires Pysa analysis results to be generated beforehand. It provides a command-line interface for querying taint models.

```Python
python3 -i scripts/explore_pysa_models.py
```

--------------------------------

### Get Types in File using Pyre Query

Source: https://pyre-check.org/docs/querying-pyre

Explains the `types` Pyre query command, which returns all resolved types for specified files. Notes that paths must be relative to the `pyre_configuration`.

```Shell
$ pyre query "types('path1', 'path2', ...)"
```

--------------------------------

### Get Global Leaks with Pyre Query

Source: https://pyre-check.org/docs/querying-pyre

The `global_leaks` command identifies mutations to global variables and class attributes within specified functions or methods. If no callables are provided, it performs no operation.

```shell
# a.py  
class A:  
    my_class_variable: int = 3  
  
    def foo(self) -> None:  
        pass  
  
```

--------------------------------

### Get Attributes of a Class with Pyre Query

Source: https://pyre-check.org/docs/querying-pyre

The `attributes` command retrieves a list of attributes for a given class. It requires the class name as an argument. The output includes the annotation and name of each attribute.

```shell
$ pyre query "attributes(a.C)"
```

--------------------------------

### Source/Sink Sanitizer Example

Source: https://pyre-check.org/docs/pysa-basics

Demonstrates how Source/Sink sanitizers are used to sanitize functions belonging to the source/sink trace. It shows a scenario where user input is passed through a safe rendering function, and how Pysa issues are avoided by modeling taint flow.

```Python
def render_string_safe(string: str):
  safe_strings_list = ["safe", "string", "list"]
  if string in safe_strings_list:
    return render(string)

def render_input_view(request: HttpRequest):
  user_input = request.GET["user_input"]
  return render_string_safe(user_input)

```

```Python
def render_string_safe(string: Sanitize[TaintSink[XSS]]): ...
```

--------------------------------

### Pysa Configuration File

Source: https://pyre-check.org/docs/pysa-running

This configuration file tells Pysa which directories contain the source code to analyze and where to find the taint model files.

```JSON
# static_analysis_example/.pyre_configuration

{
  "source_directories": ["."],
  "taint_models_path": "stubs/taint"
}

```

--------------------------------

### Add Scripts Directory to PATH for VSCode Development

Source: https://pyre-check.org/docs/installation

Adds the directory containing the custom 'pyre' executable script to the system's PATH environment variable. This ensures that the 'pyre' command can be found and executed by VSCode.

```bash
$ echo 'PATH="/path/to/pyre-check/scripts:$PATH"' >> ~/.bashrc
$ source ~/.bashrc
```

--------------------------------

### Constructor and Property Setter Modeling

Source: https://pyre-check.org/docs/pysa-basics

Shows how to use `LocalReturn` instead of `Updates[self]` for constructors and property setters, as they are treated as returning `self` by Pysa.

```Python
def MyClass.__init__(self, argument: TaintInTaintOut[LocalReturn]): ...
```

```Python
@foo.setter
def MyClass.foo(self, value: TaintInTaintOut[LocalReturn]): ...
```

--------------------------------

### Python Annotation for Class Attribute Source

Source: https://pyre-check.org/docs/pysa-basics

Illustrates annotating a class attribute in Python to be recognized as a taint source. This example marks the `COOKIES` attribute of `HttpRequest` as a 'Cookies' source.

```Python
django.http.request.HttpRequest.COOKIES: TaintSource[Cookies]  

```

--------------------------------

### Pyre Query: Less or Equal Type Comparison

Source: https://pyre-check.org/docs/querying-pyre

Demonstrates the usage of the 'less_or_equal' Pyre query command to check type compatibility between classes. It shows examples of checking if a subclass is compatible with a superclass.

```Shell
$ pyre query "less_or_equal(a.D, a.C)"
{"response":{"boolean":true}}

$ pyre query "less_or_equal(a.C, a.D)"
{"response":{"boolean":true}}
```

--------------------------------

### Initial Django Code for Taint Analysis

Source: https://pyre-check.org/docs/pysa-false-positives-negatives

This Python code snippet shows an initial Django application structure where user input is processed and potentially executed. It serves as the baseline for demonstrating taint analysis.

```Python
from django.http import HttpRequest, HttpResponse

class Runner:
    def run(self, command: str) -> None:
        eval(command)

def get_command(request: HttpRequest) -> str:
    command = request.GET["command"]
    return command

def execute_command(runner: Runner, command):
    runner.run(command)

def start(request: HttpRequest):
    command = get_command(request)
    runner = Runner()
    execute_command(runner, command)

```

--------------------------------

### Using via-type on Attributes and Globals

Source: https://pyre-check.org/docs/pysa-features

This Python example illustrates applying `via-type` to class attributes or global variables. A standalone `ViaTypeOf` is a shorthand for `TaintInTaintOut[ViaTypeOf]`, simplifying the annotation process.

```Python
my_module.MyClass.source: TaintSource[Test, ViaTypeOf] = ...
```

```Python
my_module.MyClass.sink: TaintSource[Test, ViaTypeOf] = ...
```

```Python
my_module.MyClass.my_attribute: ViaTypeOf = ...
```

--------------------------------

### Example: GraphQLSourceGenerator for Graphene Resolvers

Source: https://pyre-check.org/docs/pysa-model-generators

The GraphQLSourceGenerator generates models for graphene-style GraphQL resolver functions, annotating them with UserControlled and ReturnedToUser. It mirrors the functionality of RESTApiSourceGenerator and ExitNodeGenerator for GraphQL contexts.

```Python
from typing import Any, Callable, List

from pysa.model_generators.model_generator import ModelGenerator
from pysa.model_generators.utils import CallableModel


class GraphQLSourceGenerator(ModelGenerator):
    def __init__(self):
        super().__init__(name="GraphQLSourceGenerator")

    def _get_graphql_resolvers(self) -> List[Callable[..., Any]]:
        # Placeholder for logic to find and return all graphene resolver functions
        pass

    def _get_models(self) -> List[CallableModel]:
        models: List[CallableModel] = []
        for resolver in self._get_graphql_resolvers():
            # Annotate resolvers with UserControlled for arguments and ReturnedToUser for return values
            models.append(
                CallableModel(
                    callable=resolver,
                    parameter_names=ParameterSpec.from_callable(resolver),
                    taint_in=[("UserControlled", "*")],
                    taint_out=[("ReturnedToUser", "return")],
                )
            )
        return models

    def generate_models(self) -> List[str]:
        return [model.to_string() for model in self._get_models()]

```

--------------------------------

### Pysa Taint Models

Source: https://pyre-check.org/docs/pysa-running

These Pysa model files link source code to taint configuration, defining 'input' as a UserControlled source and 'os.system' as a RemoteCodeExecution sink.

```Python
# static_analysis_example/stubs/taint/core_privacy_security/general.pysa

# model for raw_input
def input(__prompt) -> TaintSource[UserControlled]: ...

# model for os.system
def os.system(command: TaintSink[RemoteCodeExecution]): ...

```