---

name: joblib-stub-updater description: > Detects changes between joblib versions by comparing git diffs, analyzes API changes (new/modified/removed functions, classes, parameters), and updates corresponding .pyi stub files. Use when joblib releases a new version and stubs need to be synchronized, or when the user mentions "update stubs", "joblib upgrade", "sync stubs with joblib", or "check joblib changes". license: MIT compatibility: Requires git, uv, and Python 3.11+. Internet access needed to fetch joblib releases. allowed-tools: Bash(git:) Bash(uv:) Read Write

Joblib Stub Updater

This skill helps maintain type stubs for joblib by detecting API changes between versions and updating .pyi files accordingly.

Workflow Overview

Copy1. Detect Version Change  →  2. Generate Diff  →  3. Analyze Changes  →  4. Update Stubs  →  5. Validate

Step 1: Check Current and Latest Versions

First, determine what versions we're working with:

Copy# Check currently stubbed version (from pyproject.toml or installed)
uv run python -c "import joblib; print(joblib.__version__)"

# Check latest available version from PyPI
curl -s https://pypi.org/pypi/joblib/json | uv run python -c "import sys, json; print(json.load(sys.stdin)['info']['version'])"

Step 2: Clone Joblib and Generate Diff

Clone the joblib repository and generate a diff between versions:

Copy# Clone joblib to a temp directory (skip if already exists)
if [ ! -d /tmp/joblib-source ]; then
    git clone --depth=100 https://github.com/joblib/joblib.git /tmp/joblib-source
fi

# Navigate to the repository and update tags
cd /tmp/joblib-source
git fetch --tags

# List available tags
git tag --sort=-v:refname | head -20

# Generate diff between two versions (e.g., 1.3.0 to 1.4.0)
git diff <OLD_TAG>..<NEW_TAG> -- joblib/*.py joblib/**/*.py

Step 3: Analyze API Changes

Run the analysis script to identify what changed:

Copyuv run python skills/joblib-stub-updater/scripts/analyze_changes.py \
    --old-version <OLD_TAG> \
    --new-version <NEW_TAG> \
    --joblib-path /tmp/joblib-source

The script will output:

• New exports: Functions/classes added to __all__ or public API
• Removed exports: Functions/classes removed from public API
• Signature changes: Parameters added, removed, or type-changed
• New modules: Entirely new .py files
• Deprecated items: Functions/classes marked as deprecated

Manual Diff Analysis

If the script is unavailable, manually analyze the diff:

Copy# Navigate to joblib source (assumes Step 2 completed)
cd /tmp/joblib-source

# Focus on public API changes
git diff <OLD_TAG>..<NEW_TAG> -- joblib/__init__.py

# Check specific module changes
git diff <OLD_TAG>..<NEW_TAG> -- joblib/memory.py
git diff <OLD_TAG>..<NEW_TAG> -- joblib/parallel.py

# Look for signature changes (def lines)
git diff <OLD_TAG>..<NEW_TAG> -- 'joblib/*.py' | grep -E '^\+.*def |^\-.*def '

Step 4: Update Stub Files

For each identified change, update the corresponding .pyi file:

Adding New Function

Copy# In src/joblib-stubs/<module>.pyi
def new_function(
    param1: str,
    param2: int = ...,
    *,
    keyword_only: bool = ...,
) -> ReturnType: ...

Adding New Class

Copyclass NewClass:
    attr: ClassVar[int]
    
    def __init__(self, param: str) -> None: ...
    def method(self, arg: int) -> str: ...

Modifying Signatures

When a function signature changes:

1. Check the new signature in joblib source
2. Update parameter types and return type
3. Add overloads if the function has multiple valid signatures

Copy@overload
def func(x: int) -> int: ...
@overload  
def func(x: str) -> str: ...
def func(x: int | str) -> int | str: ...

Removing Deprecated Items

If something is removed:

1. Check if it's in stubs
2. Remove from .pyi file
3. Remove from __init__.pyi re-exports if applicable

Step 5: Validate Changes

After updating stubs, run full validation:

Copycd /path/to/joblib-stubs

# Format and lint
uv run poe lint

# Type check with both checkers
uv run poe pyright
uv run poe mypy

# Run affected tests
uv run pytest src/tests/test_<module>.py -v

Example: Complete Update Flow

Scenario: Update from joblib 1.3.2 to 1.4.0

Copy# 1. Setup - Clone joblib repository
if [ ! -d /tmp/joblib-source ]; then
    git clone --depth=100 https://github.com/joblib/joblib.git /tmp/joblib-source
fi
cd /tmp/joblib-source
git fetch --tags

# 2. Generate diff
git diff 1.3.2..1.4.0 -- 'joblib/*.py' > /tmp/joblib-diff.patch

# 3. Review public API changes
git diff 1.3.2..1.4.0 -- joblib/__init__.py
git diff 1.3.2..1.4.0 -- joblib/parallel.py | head -100

# 4. Check new function signatures
git show 1.4.0:joblib/parallel.py | grep -A 20 "def new_function"

# 5. Update stub - Navigate back to stub repository
cd /home/phi/git/python/repo/joblib-stubs
# Edit src/joblib-stubs/parallel.pyi to add new_function

# 6. Validate
uv run poe lint && uv run poe pyright && uv run poe mypy

Change Categories & Actions

Tips

1. Always verify runtime behavior first:

   Copyuv run python -c "import inspect; from joblib import X; print(inspect.signature(X))"
   

2. Check if default values matter for types:

   Copy# If default is None, the type should include None
   def func(param: str | None = ...) -> str: ...
   

3. Handle *args and **kwargs properly:

   Copydef func(*args: Any, **kwargs: Any) -> Result: ...
   

4. Use _typeshed.pyi for complex internal types

5. Write tests for new additions following the patterns in AGENTS.md

Reference Files

• REFERENCE.md - Detailed stub writing conventions
• analyze_changes.py - Automated change analysis script