Test against upgraded dependencies

The scheduled cron job will include upgraded dependencies in the
build matrix and the workflow will allow this as an option.

.github/workflows/pytest.yml

@@ -8,16 +8,44 @@ on:
   pull_request:
     branches: [ main ]
   workflow_dispatch:
+    inputs:
+      upgraded:
+        description: "Include upgraded dependencies in build matrix"
+        default: false
+        type: boolean
   schedule:
     - cron: "0 0 * * *"
 
 jobs:
-  build:
+  info:
+    name: Collect information & changes data
+    outputs:
+      dependencies: ${{ steps.info.outputs.dependencies }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: Collect information
+        id: info
+        run: |
+          dependencies='["pinned", "upgraded"]'
+
+          if [[ "${{ github.event_name }}" == "push" ]] || \
+             [[ "${{ github.event_name }}" == "pull_request" ]] || \
+             [[ "${{ github.event.inputs.upgraded }}" == "false" ]];
+          then
+            dependencies='["pinned"]'
+          fi
 
+          # Output & sent to GitHub Actions
+          echo "dependencies: ${dependencies}"
+          echo "dependencies=${dependencies}" >> $GITHUB_OUTPUT
+  build:
     runs-on: ubuntu-latest
+    needs:
+      - info
     strategy:
       fail-fast: false
       matrix:
+        dependencies: ${{ fromJSON(needs.info.outputs.dependencies) }}
         python-version: ["3.12"]
 
     steps:
@@ -29,7 +57,21 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
+
+        if [[ "${{ matrix.dependencies }}" == "upgraded" ]];
+        then
+          echo "unpinning dependencies"
+          ./script/unfreeze
+        fi
+
         pip install -r requirements.test.txt
+
+        if [[ "${{ matrix.dependencies }}" == "upgraded" ]];
+        then
+          ./script/freeze
+          echo "dependency changes after upgrade:"
+          git diff requirements.test.txt
+        fi
     - name: Test with pytest
       run: |
         pytest

script/unfreeze

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+
+set -e
+
+cd "$(dirname "$0")/.."
+
+cat requirements.test.txt | \
+	sed 's/==.*//' > requirements.test.txt.tmp && \
+	mv requirements.test.txt.tmp requirements.test.txt