Changelog

Unreleased

0.8.2

  • Add a -q/--quiet flag to decrease verbosity.

  • Log messages printed during slyp runs are now sent to stderr. stdout is reserved for linting messages and for fixer output when running on stdin.

  • Minor bugfix to the matching AST linter: some nodes were skipped when analyzing ifs.

  • Fix matching AST linter short-circuiting too early upon finding one error.

0.8.1

  • Bugfix: clear stale caches which could be incorrectly used in v0.8.0

0.8.0

  • Fix an ordering bug under libcst version 1.5.0 . New validation prevents the generation of invalid if nodes, which slyp was generating and then fixing. This applies to certain cases in which an if was not followed by a space, as in if(x): pass. These cases may now require two runs to converge.

  • Add fixer behavior to add a -> None return type annotation to __init__ methods which have no return type annotation.

0.7.1

  • Fix a bug in which list(reversed(foo)) was transformed to reversed(foo).

  • Improve the handling of whitespace when wrapping concatenated strings

0.7.0

  • New autofixing behavior has been added, inspired by the rules of flake8-comprehensions. The following autofixing behaviors are newly added:

    • Calls to dict(), list(), and tuple() with no arguments are replaced with the relevant literals, {}, [], and ().

    • Calls to set() and list() on generator expressions are converted to set and list comprehensions.

    • Calls to dict() with keyword arguments are converted to dict literal syntax. e.g., dict(x=1) becomes {"x": 1}

    • Calls to set() and frozenset() whose argument is a builtin which produces an iterable are unwrapped. e.g., set(list(foo())) becomes set(foo())

    • Calls to list() whose argument is a builtin which produces a list are unwrapped. e.g., list(sorted(foo)) becomes sorted(foo)

Note

The new transformation can be unsafe in certain rare cases. Specifically, the builtin names can be rebound to user-defined callables. This would potentially result in the fixer converting a meaningful call to these user-defined values.

This can only occur if you rebind very well-known names, e.g., def dict(...): ...

Because there are no well-known cases in which such name shadowing is important or essential, this is not considered a bug. Just don’t shadow these builtin names like that. You can always disable fixing with comments for certain lines.

0.6.1

  • Enable autofixing of some concatenated strings which combine f-strings with simple strings, as long as no extra escaping is needed

  • Autofixing can be disabled with comments containing slyp: disable, slyp: disable=format, or fmt: off. Inverse comments, slyp: enable and fmt: on can be used to re-enable autofixing.

0.6.0

  • Unexpected errors encountered when parsing files are now reported as failures, rather than causing slyp to abort

  • Replace E110 with autofixer behavior, which rewrites the return of a known-None variable immediately after testing it to return None instead

  • Replace W102 with autofixer behavior, which parenthesizes multiline concatenated strings in dict elements

  • Replace W103 with autofixer behavior, which parenthesizes multiline concatenated strings in tuple, list, and set literals if there is more than one element

  • Add the --only flag, enabling --only=lint or --only=fix to run only the linting or fixing

  • Add basic support for reading data from stdin, in which case - --only must be used - if --only=fix, then the resulting file is always written to stdout

  • Implement an additional check for unnecessary string concatenation, E101

0.5.0

  • Replace the W101 lint with autofixer behavior, which will insert the necessary parentheses

  • Improve the way that files are handled to read only once from disk per file

  • slyp now processes files in parallel and produces its output at the end of its run (with some simple sorting)

0.4.1

  • Fix passing file caching to correctly record successes after a failure

  • The cache implementation has been improved to cache by file contents rather than path, allowing duplicate files to share a cache entry

0.4.0

  • Various performance improvements, especially for fixing

  • slyp will now cache results for files which pass all checks in .slyp_cache, thus avoiding rechecking files which pass and have not changed

    • this behavior can be disabled with --no-cache

    • the cache is maintained independently for each possible set of --enable/--disable options passed to slyp

    • projects which fully pass slyp checking should experience the greatest improvement – as great as 50x faster on sizable production codebases with a populated cache

0.3.0

  • Fix the handling of parenthesized lambdas in the fixer. The innermost parentheses arounda lambda are now preserved.

  • Minor speed enhancements.

  • Fix the handling of autofixing in certain expressions when there is no whitespace between a hard keyword and a parenthesis, inserting spaces when necessary.

  • Fix unnecessarily parenthesized with and from ... import ... statements.

  • Preserve parentheses immediately under unary operations, as they may aid readability.

  • Remove W120. It is automatically fixed by the latest black versions.

  • In restricted cases, the fixer will now automatically join implicitly concatenated strings when there is no newline. This autofix covers some cases of E100.

0.2.2

  • Preserve the innermost parentheses when used inside of splat-argument expansion. e.g., foo(*("a b".split())) is NOT fixed to foo(*"a b".split()). This is semantically equivalent to the version with the parentheses removed, but not as obvious to readers.

0.2.1

  • Fix unnecessary paren fixer aggressively fixing Comparison nodes. Add this to the set of nodes which retain their innermost parens.

0.2.0

  • Improve handling on non-UTF8 files under --use-git-ls

  • Helptext (slyp --help) now does not list all linting codes. Use slyp --list to view this data.

  • Introduce autofixer behavior. Fixing is always run before linting, so that emitted lint errors are accurate to the fixed file.

    • The first autofixer has been added: remove unnecessary parentheses for expressions wrapped in multiple parentheses.

0.1.2

  • Add W120 for catching unparenthesized multiline annotations on parameters

0.1.1

  • If CST traversal hits recursion depth, this is now reported as an internal error without aborting the entire run of slyp

  • W103 now ignores a multiline string join which is the only string inside of a container type.

0.1.0

  • --disable and --enable now support the special string “all” to refer to all codes. Explicit enables and disables are given higher precedence than “all”.

  • Add E110 for catching the return of a known-None variable immediately after testing it (prefer to return None, not the variable name)

  • --disable and --disable now support categories, as in --disable W to disable all warnings.

  • The E101, E102, and E103 codes have each been downgraded to warnings (W category) but are still enabled by default

  • The matching AST checker now considers the triviality and proximity of matching AST nodes. By default, only the check for non-trivial adjacent branches is enabled.

    • Add W201, W202, and W203 to describe the disabled checks

    • Triviality is defined as a heuristic which captures simple expressions and statements (e.g. return None is a trivial statement)

  • Add support for --enable to turn on disabled codes

0.0.3

  • Add --disable for turning off specific codes

  • Various minor speed improvements, resulting in ~5% faster runs on large codebases

  • Invert verbosity control by removing -q/--quiet and adding -v/--verbose. Verbose output is now opt-in, not opt-out.

0.0.2

  • Add pre-commit-hooks config, allowing use with pre-commit

0.0.1

  • Initial release