From e57783863113d35e6398984e74de0060e4da9362 Mon Sep 17 00:00:00 2001
From: wisp3rwind <17089248+wisp3rwind@users.noreply.github.com>
Date: Sat, 17 Dec 2022 22:20:33 +0100
Subject: [PATCH 1/3] add mypy tox environment and dependencies

---
 setup.py |  9 +++++++++
 tox.ini  | 10 +++++++++-
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/setup.py b/setup.py
index d49ed65b2..a6984ffd2 100755
--- a/setup.py
+++ b/setup.py
@@ -119,6 +119,15 @@ setup(
             'flake8-docstrings',
             'pep8-naming',
         ],
+        'mypy': [
+            'mypy',
+            'types-Pillow',
+            'types-urllib3',
+            'types-beautifulsoup4',
+            'types-PyYAML',
+            'types-requests',
+            'types-Flask-Cors',
+        ],
 
         # Plugin (optional) dependencies:
         'absubmit': ['requests'],
diff --git a/tox.ini b/tox.ini
index 1c0a984ed..861101e0f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,7 +4,7 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = py38-{cov,lint}, docs
+envlist = py38-{cov,lint,mypy}, docs
 
 [_test]
 deps = .[test]
@@ -13,15 +13,23 @@ deps = .[test]
 deps = .[lint]
 files = beets beetsplug beet test setup.py docs
 
+[_mypy]
+deps =
+    .[mypy]
+    .[test]
+
 [testenv]
 deps =
     {test,cov}: {[_test]deps}
     lint: {[_lint]deps}
+    mypy: {[_mypy]deps}
 passenv = INTEGRATION_TEST
 commands =
     test: python -bb -m pytest -rs {posargs}
     cov: coverage run -m pytest -rs {posargs}
     lint: python -m flake8 {posargs} {[_lint]files}
+    mypy: mypy -p beets -p beetsplug
+    mypy: mypy test
 
 [testenv:docs]
 basepython = python3.10

From d604c7e175ed117162681d09770f81ae8677a9f4 Mon Sep 17 00:00:00 2001
From: wisp3rwind <17089248+wisp3rwind@users.noreply.github.com>
Date: Sat, 17 Dec 2022 22:23:06 +0100
Subject: [PATCH 2/3] add mypy to actions, but allow failure

---
 .github/workflows/ci.yaml | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index b3472e412..96b230c59 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -54,6 +54,15 @@ jobs:
         run: |
           tox -vv -e py-cov
 
+      - name: Test latest Python version with tox and mypy
+        if: matrix.python-version == '3.10'
+        # continue-on-error is not ideal since it doesn't give a visible
+        # warning, but there doesn't seem to be anything better:
+        # https://github.com/actions/toolkit/issues/399
+        continue-on-error: true
+        run: |
+          tox -vv -e py-mypy
+
       - name: Test nightly Python version with tox
         if: matrix.python-version == '3.11-dev'
         # continue-on-error is not ideal since it doesn't give a visible

From d15c5c4ba246d5866c945342cc09b29d2e849c5c Mon Sep 17 00:00:00 2001
From: wisp3rwind <17089248+wisp3rwind@users.noreply.github.com>
Date: Sat, 17 Dec 2022 22:32:30 +0100
Subject: [PATCH 3/3] mypy: ignore_missing_imports = True

---
 .mypy.ini | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .mypy.ini

diff --git a/.mypy.ini b/.mypy.ini
new file mode 100644
index 000000000..b47e5dff3
--- /dev/null
+++ b/.mypy.ini
@@ -0,0 +1,5 @@
+[mypy]
+# FIXME: Would be better to actually type the libraries (if under our control),
+# or write our own stubs. For now, silence errors
+ignore_missing_imports = True
+