salazaar

Make your codebase speak snake'ish! 🐍

salazaar is a library that transpiles JavaScript code into syntax-correct Python code.

Main goal is to help you migrate legacy, untyped JS projects into the modern Python ecosystem as smoothly as possible.

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Features

• Converts JavaScript code to Python code
• Focuses on generating code that's ready to execute (with some manual tweaks)
• Eases the transition from JS to Python for large codebases

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Usage

There are 2 options to use salazaar:

• as library

      import salazaar
      js_code = "let result = true ? 1: 0"
  
      # unsafe_fixes & comments are optional arguments
      py_code = salazaar.translate(js_code, unsafe_fixed=True, comments=False)
  
      assert "result = 1 if True else 0"

• in command line

  > "let result = 1" | python -m salazaar
  result = 1 if True else 0

How it works

salazaar works by converting JavaScript AST to valid Python AST.

It uses esprima-python as JavaScript AST reader.

What salazaar implements are rules for converting AST, many of which are opinionated. Those languages differ and many features needs to be replaces with something "sensible" in Python language.

Except for syntax salazaar also allows for functions/methods conversion. To check which functions are translated please unsafe_fixes Unfortunately library doesn't infer JS types so those conversions are based on names and syntax. That's why those are categorized as "unsafe_fixes". It's best to be carefull with them and check how they perform for given code base.

unsafe_fixes

Here is currently implemented list of JavaScript functions converted

• .toString
• Array.join
• Array.push
• Array.slice
• Array.sort
• JSON.parse
• JSON.stringify
• regex literals
• string.concat
• string.match
• string.matchAll
• string.replace
• string.split
• string.substr
• string.substring
• string.test
• string.toLowerCase
• string.toUpperCase
• string.trim

Limitations

• Not a Silver Bullet: The tool is designed to simplify, not fully automate, the migration process.
• Type Inference: No automatic JS type inference; some function calls may not convert directly.
• Built-in Libraries: Many JS built-ins are not translated and may need custom handling.
• Variable Scoping: Differences in global/non-local variables and var behavior may require manual adjustments.

Documentation

• Example translations and requirements are documented in the tests/markdown directory.
• These markdown files serve as both documentation and a specification for running test suite

Contributing

If you are interested in this project feel free to contribute! Please open issues for bugs or feature requests, and submit pull requests to help improve salazaar.

License

MIT License. See LICENSE for details.