Add tox env to validate requirements

This will check that our requirements are appropriately compiled.

.github/workflows/backend.yml

@@ -4,21 +4,21 @@ on:
   workflow_dispatch:
     paths:
       - '**.py'
-      - 'requirements/**.txt'
+      - 'requirements/**.in'
       - '**.html'
       - '**.mo'
       - '**.po'
   pull_request:
     paths:
       - '**.py'
-      - 'requirements/**.txt'
+      - 'requirements/**.in'
       - '**.html'
       - '**.mo'
       - '**.po'
   merge_group:
     paths:
       - '**.py'
-      - 'requirements/**.txt'
+      - 'requirements/**.in'
       - '**.html'
       - '**.mo'
       - '**.po'
@@ -34,6 +34,7 @@ jobs:
           - validate-migrations
           - validate-assets
           - validate-translations
+          - validate-requirements
           - unittest
 
     services:

tox.ini

@@ -172,7 +172,7 @@ commands=
 # Invoke with: tox -e validate-translations
 # Ensure that there are no changes to translatable strings that aren't
 # contained in the comitted portable object files.
-# This ultimate tests whether the generated django.mo file has changed
+# This ultimately tests whether the generated django.mo file has changed
 # (the django.po file will change because it includes the date it was
 # generated).
 # NOTE: Requires gettext. Will overwrite any existing
@@ -191,6 +191,24 @@ commands=
     git diff --quiet */locale/*/LC_MESSAGES/django.mo
 
 
+[testenv:validate-requirements]
+# Invoke with: tox -e validate-requirements
+# Ensure that there are no changes to dependencies in our requirements/*.in
+# files that haven't been compiled to the requirements/*.txt files.
+# NOTE: Will overwrite any existing requirements/*.txt files
+recreate=False
+envdir={toxworkdir}/unittest
+deps=
+    {[unittest-config]deps}
+setenv={[unittest-config]setenv}
+allowlist_externals=
+    ./compile-requirements.sh
+    git
+commands=
+    ./compile-requirements.sh
+    git diff --quiet requirements/*.txt
+
+
 [testenv:coverage]
 # Invoke with: tox -e coverage
 # Report out the coverage of changes on the current branch against the main