name: Run mypy_primer

on:

# Only run on PR, since we diff against main

pull_request:

paths:

- ".github/workflows/mypy_primer.yml"

- ".github/workflows/mypy_primer_comment.yml"

- "numpy/**/*.pyi"

- "numpy/_typing/*.py"

- "numpy/typing/*.py"

- "!numpy/typing/tests/**"

- "numpy/py.typed"

concurrency:

group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}

cancel-in-progress: true

permissions:

contents: read

jobs:

mypy_primer:

name: Run

runs-on: ubuntu-latest

strategy:

matrix:

shard-index: [0] # e.g. change this to [0, 1, 2] and --num-shards below to 3

fail-fast: false

steps:

- uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2

with:

path: numpy_to_test

fetch-depth: 0

- uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0

with:

python-version: "3.12"

- name: Install dependencies

# To update: replace commit hash (no tags/releases available, use HEAD of master)

run: pip install git+https://github.com/hauntsaninja/mypy_primer.git@05f73ec3d85bb4f55676f3c57f2c3e5136228977 # HEAD of master on 2026-03-04

- name: Run mypy_primer

shell: bash

run: |

cd numpy_to_test

MYPY_VERSION=$(grep mypy== requirements/typing_requirements.txt | sed -n 's/mypy==\([^;]*\).*/\1/p')

echo "new commit"

git checkout $GITHUB_SHA

git rev-list --format=%s --max-count=1 HEAD

MERGE_BASE=$(git merge-base $GITHUB_SHA origin/$GITHUB_BASE_REF)

git worktree add ../numpy_base $MERGE_BASE

cd ../numpy_base

echo "base commit"

git rev-list --format=%s --max-count=1 HEAD

echo ''

cd ..

# fail action if exit code isn't zero or one

# TODO: note that we don't build numpy, so if a project attempts to use the

# numpy mypy plugin, we may see some issues involving version skew.

(

mypy_primer \

--new v${MYPY_VERSION} --old v${MYPY_VERSION} \

--known-dependency-selector numpy \

--old-prepend-path numpy_base --new-prepend-path numpy_to_test \

--num-shards 1 --shard-index ${{ matrix.shard-index }} \

--additional-flags="--python-version=3.12" \

--debug \

--output concise \

| tee diff_${{ matrix.shard-index }}.txt

) || [ $? -eq 1 ]

- if: ${{ matrix.shard-index == 0 }}

name: Save PR number

run: |

echo ${{ github.event.pull_request.number }} | tee pr_number.txt

- name: Upload mypy_primer diff + PR number

uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1

if: ${{ matrix.shard-index == 0 }}

with:

name: mypy_primer_diffs-${{ matrix.shard-index }}

path: |

diff_${{ matrix.shard-index }}.txt

pr_number.txt

- name: Upload mypy_primer diff

uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1

if: ${{ matrix.shard-index != 0 }}

with:

name: mypy_primer_diffs-${{ matrix.shard-index }}

path: diff_${{ matrix.shard-index }}.txt

join_artifacts:

name: Join artifacts

runs-on: ubuntu-latest

needs: [mypy_primer]

permissions:

contents: read

steps:

- name: Merge artifacts

uses: actions/upload-artifact/merge@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1

with:

name: mypy_primer_diffs

pattern: mypy_primer_diffs-*

delete-merged: true