From 5664d341509f75b93d9eaf4aa436685ed80ea016 Mon Sep 17 00:00:00 2001
From: Remco de Boer <29308176+redeboer@users.noreply.github.com>
Date: Thu, 19 Jan 2023 14:32:07 +0100
Subject: [PATCH] DX: run `linkcheck` on GitHub Actions

See also https://github.com/ComPWA/repo-maintenance/issues/57
---
 .cspell/this-project.txt      |  1 +
 .github/workflows/ci-docs.yml | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/.cspell/this-project.txt b/.cspell/this-project.txt
index 0a388a44..d712f034 100644
--- a/.cspell/this-project.txt
+++ b/.cspell/this-project.txt
@@ -14,6 +14,7 @@ latexmk
 LATEXMKOPTS
 LATEXOPTS
 latexpdf
+linkcheck
 lualatex
 MAINT
 Mikhasenko
diff --git a/.github/workflows/ci-docs.yml b/.github/workflows/ci-docs.yml
index ad898f97..57b97d49 100644
--- a/.github/workflows/ci-docs.yml
+++ b/.github/workflows/ci-docs.yml
@@ -68,11 +68,32 @@ jobs:
           name: latex
           path: docs/_build/latex
 
+  linkcheck:
+    name: Check external links
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/cache@v3
+        with:
+          key: |
+            ${{ github.workflow }}-${{ github.job }}-${{ runner.os }}-${{ hashFiles('.constraints/py3.*.txt', 'setup.cfg') }}
+          path: |
+            ~/.cache/pip/
+      - uses: actions/setup-python@v4
+        with:
+          python-version: "3.8"
+      - name: Install Python dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install -c .constraints/py3.8.txt -e .[doc] tox
+      - run: tox -e linkcheck
+
   documentation:
     name: Run notebooks and build documentation
     needs:
       - html-fast
       - pdf-fast
+      - linkcheck
     if: github.event_name != 'pull_request'
     runs-on: ubuntu-22.04
     steps: