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Releases: facebook/pyrefly

v0.20.0

16 Jun 19:40
@lolpack lolpack
0.20.0
5bea083

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v0.20.0

Pyrefly 0.20.0

Status : ALPHA
Release date: 16 June 2025

Pyrefly 0.20.0 represents 165 commits from 21 contributors and focuses on stability, friendlier diagnostics, and CLI quality-of-life.

Special thanks to @TheRustyPickle, @ducdetronquito, @pt2302, @akmalsoliev and every reviewer, tester and bug-reporter who helped make this release!

✨ New & Improved

Area What’s new
Diagnostics & error messages •We now print a snippet of source code in each message, highlighting the error location. You can control error message verbosity with the new --output-format=min-text and --output-format=full-text options.
•Add tests to keep Error Kinds in sync with documentation, in addition to reclassifying Error Kinds previously reported as Unknown (#477).
• Import errors are now shown on separate lines with source hints, thanks to the new BindingsBuilder::error_multiline helper (commit 2bba00f).
•TypeVar reveal output is shorter and clearer – no more variance=PInvariant noise (#225).
Editor support •Basic support for Semantic Highlighting, a highly requested feature (#218). More improvements to come in future releases.
Configuration / CLI • New flags --replace-imports-with-any and --ignore-missing-source let you suppress noisy import errors without editing config files (#480 → closes #460 & #462).
Type-system smarts • Conflicting Required/NotRequired qualifiers in a single TypedDict field now surface an explicit error (#447→ fixes #414).
Project workflow • pyrefly init edits an existing pyproject.toml in-place instead of appending duplicate [tool.pyrefly] sections (#336).

🐛 Other notable bug fixes

  • Panics fixed:
    • Missing NoneType stub when running with --python-version 3.9 (#56).
    • Starred targets in augmented assignments no longer crash the checker (#468).
  • Hover & go-to-definition no longer crash the LSP on keyword-only or pattern-match bindings.
  • Build is quiet again on nightly Rust; cleaned up stray clippy warnings.

🚨 Potentially breaking

  • Flag & message renames – some diagnostics switched from snake-case to kebab-case and new CLI flags were introduced (#480). Update any scripts that parse pyrefly check --help or grep error kinds.
  • The TypedDict qualifier rule (#447) may surface new errors where both Required and NotRequired were previously accepted.

📦 Upgrade

pip install --upgrade pyrefly==0.20.0

🖊️ Contributors in this release

@rchen152, @grievejia, @stroxler, @ajaymiranda, @connernilsen, @pt2302, @kinto0, @yangdanny97, @ndmitchell, @migeed-z, @hugovk, @dtolnay, @Alex-Aron, @Adist319, @zachmullen, @grantlouisherman, @rubmary, @dluo, @maggiemoss, @kinto0, @SamChou19815

Contributors

zachmullen, stroxler, and 21 other contributors
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v0.19.0

10 Jun 20:02
@lolpack lolpack
0.19.0
b1a9987

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v0.19.0

Pyrefly 0.19.0

Status : ALPHA

Release date: 9 June 2025

Pyrefly 0.19.0 packs a week’s worth of fixes and quality‑of‑life improvements into 128 commits from 19 contributors, touching 153 files.

Thank you @ajaymiranda @Adist319 @Alex-Aron @zachmullen for your contributions!

✨ New & Improved

Area What’s new
Editor support • Neovim integration — first‑class LSP support plus a helper command to install/update the server (#227).
• Neovim now respects pyrefly.toml and remote config overrides (#442).
Configuration UX • Eliminates misleading “Extra keys” parse errors in pyrefly.toml (#441).
• Added validation that a TypedDict field cannot be both Required and NotRequired (#414).
Diagnostics • reveal_type messages are now INFO‑level instead of errors, so they no longer fail CI runs when you’re just inspecting types (#304).
• isinstance() checks involving Union[...] are now inferred correctly (#426).
Type‑system smarts • Better handling of Self generics in chained method calls (#152).
• Fixed constrained TypeVar attribute access (#318).
• Fixed failure when calling methods on a plain TypeVar (#150).
Stub & third‑party typing • Works with inline stub files that live beside their implementation (#419).
• Correctly recognises pandas-stubs generic aliases such as Index without type arguments (#427).

🐛 Other notable bug fixes

  • Duplicate “NoReturn / Never” return‑annotation error reduced to a single authoritative report (#425).
  • Numerous minor LSP crashes and hover glitches fixed.
  • Documentation on website and CLI cleanup

🚨 Potentially breaking

  • The new TypedDict qualifier rule (#414) will surface errors in code that previously passed silently.
  • If you relied on reveal_type raising an error exit status, update scripts to look for an info‑level diagnostic instead (#304).

📦 Upgrade

pip install --upgrade pyrefly==0.19.0

🖊️ Contributors in this release

@Adist319, @Alex-Aron, @connernilsen, @yangdanny97, @dluo , @dtolnay, @hugovk, @grantlouisherman, @grievejia, @kinto0, @maggiemoss, @ndmitchell, @rchen152, @rubmary, @SamChou19815, @stroxler, @migeed-z

Contributors

zachmullen, stroxler, and 17 other contributors
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