flowcompass 0.1.1

A tool to generate flow diagrams from source code

📘 Project Documentation: Python Function Execution Flow Tracer

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📌 Overview

This tool statically analyzes a Python codebase to trace the full execution flow of a given top-level function. It parses all files, identifies all function definitions and call relationships, and generates:

• A printable tree view of the function call hierarchy.
• A nested JSON report with detailed metadata for each function.
• A html flow chart with the function call hierarchy and detailed codeflow.

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Installation

pip install flowcompass

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⚙️ Command-Line Usage

flowcompass \
  --source-dir ./my_project \
  --function-name create_book_api

Available Flags

Flag	Description	Default
--source-dir	Path to root codebase	Required
--function-name	Function to trace	Required
--include-external	Include undefined/external calls	False
--skip-threaded	Skip threaded/parallel calls	False
--output-json	Output path for JSON report	<function_name>_report.json
--print-tree	Print tree to stdout	True

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🧪 Example

Given the function create_book_api, the output might be:

create_book_api (app.py) [Main api handler for creating book]
|-- validate_input (helpers/create_book_helper.py) [validates the input given by user]
|   |-- input_validation (utility/inputvalidator.py) [simple input check]
|-- format_response (helpers/format_response.py) []

JSON saved as:

create_book_api_report.json

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✅ Key Features

Feature	Description
Recursive Analysis	Builds a full tree of function calls starting from any named function.
Source-Aware	Resolves internal calls across multiple files and directories.
External Call Detection	Optionally includes external library or undefined calls.
Threaded Call Tracking	Detects calls made via Thread, ThreadPoolExecutor.submit(), etc.
Recursion Detection	Flags recursive calls to avoid infinite loops.
Call Metadata	Captures function name, docstring, file, line number, call line, and source code.

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🏗️ Architecture

1. Function Indexer

• Walks through all .py files in the provided directory.
• Uses ast to find all top-level and class-level function definitions.
• Stores them in a function index:
  Dict[str, List[FunctionMeta]]

2. AST Analyzer

• Recursively visits ast.Call nodes within a function body.
• Resolves which functions are being called (via name or attribute).
• Creates a tree of FunctionCallNode objects representing call flow.

3. Call Tree Builder

• Builds a call tree with these fields:
  • func_name, qualified_name, file_path, lineno, call_line
  • threaded, external_call, is_recursive
  • child_calls: nested list of other FunctionCallNodes

4. Output Renderer

• Tree print view using |-- format.
• JSON export for structured output or further integration.

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🧩 JSON Output Schema

Each node in the call tree has this format:

{
  "func_name": "validate_input",
  "qualified_name": "helpers.input.validate_input",
  "file_path": "helpers/input.py",
  "lineno": 12,
  "call_line": 25,
  "func_docstring": "Validates the input",
  "func_code": "def validate_input(...): ...",
  "call_order": 1,
  "external_call": false,
  "is_recursive": false,
  "threaded": false,
  "child_calls": [ ... ]
}

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🧵 Threaded Call Detection

The tool detects function calls passed into:

• executor.submit(...)
• threading.Thread(target=...)

These are flagged as:

"threaded": true

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🚧 Handling Edge Cases

Case	Handling Strategy
External calls	Skipped by default, include with --include-external
Threaded calls	Included by default, skip with --skip-threaded
Recursive calls	Tracked with visited set and is_recursive flag
Function name collisions	Disambiguated via file + qualified name
Missing root function	Graceful error message

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🔄 Future Enhancements

Idea	Description
HTML report	Interactive call tree in browser
Graphviz/DOT export	For visual flow diagrams
Full class-method resolution	Map all method calls to their class
Asynchronous (async def) support	Track coroutine flows

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🧠 Requirements

• Python 3.6+
• No external libraries required — uses ast, os, json, argparse