Validate NEWS files with rstcheck.

.github/workflows/python-linters.yml

@@ -44,3 +44,17 @@ jobs:
       run: >-
         python -m tox
       env: ${{ matrix.env }}
+
+  news_format:
+    name: Check NEWS format
+    runs-on: ubuntu-18.04
+    steps:
+    - uses: actions/checkout@master
+    - name: Set up Python
+      uses: actions/setup-python@v1
+      with:
+        version: 3.7
+    - name: Install nox
+      run: pip install nox
+    - name: Check NEWS format
+      run: nox -s validate_news

noxfile.py

@@ -1,6 +1,7 @@
 """Release time helpers, executed using nox.
 """
 
+import glob
 import io
 import subprocess
 
@@ -30,6 +31,18 @@ def get_author_list():
     return sorted(authors, key=lambda x: x.lower())
 
 
+# -----------------------------------------------------------------------------
+# Ad-hoc commands
+# -----------------------------------------------------------------------------
+@nox.session
+def validate_news(session):
+    session.install("rstcheck")
+
+    news_files = sorted(glob.glob("news/*"))
+
+    session.run("rstcheck", *news_files)
+
+
 # -----------------------------------------------------------------------------
 # Commands used during the release process
 # -----------------------------------------------------------------------------

pyproject.toml

@@ -8,7 +8,7 @@ filename = "NEWS.rst"
 directory = "news/"
 title_format = "{version} ({project_date})"
 issue_format = "`#{issue} <https://github.com/pypa/pip/issues/{issue}>`_"
-template = "news/_template.rst"
+template = "tools/automation/news/template.rst"
 type = [
   { name = "Process",                   directory = "process", showcontent = true },
   { name = "Deprecations and Removals", directory = "removal", showcontent = true },