Add version checks

.github/workflows/validate.yml

@@ -15,14 +15,15 @@ permissions:
   pull-requests: read
 
 jobs:
-  # Main filter detecting where in the repo changes have been made, allowing us to be smart about how we respond
+
   detect-changes:
     runs-on: ubuntu-latest
     outputs:
       lint: ${{ steps.check.outputs.lint }}
     steps:
       - uses: actions/checkout@v4
 
+      # Take different actions depending on what changed
       - uses: dorny/paths-filter@v3
         id: check
         with:
@@ -31,7 +32,33 @@ jobs:
               - 'tb_pulumi/**'
               - '.github/workflows/validate.yml'
 
-  # Run Ruff against tb_pulumi
+  detect-versions:
+    runs-on: ubuntu-latest
+    outputs:
+      branch-exists: ${{ steps.branch-exists.outputs.exists }}
+      version: v${{ steps.version.outputs.value }}
+    steps:
+      # Detect version from pyproject.toml
+      - uses: SebRollen/[email protected]
+        id: version
+        with:
+          file: pyproject.toml
+          field: project.version
+      - uses: GuillaumeFalourd/branch-exists@v1
+        id: branch-exists
+        with:
+          branch: v${{ steps.version.outputs.value }}
+
+  # Fail on version collision
+  version-collision:
+    needs: detect-versions
+    runs-on: ubuntu-latest
+    if: needs.detect-versions.outputs.branch-exists == 'true'
+    steps:
+      - name: "Error: version collision"
+        run: exit 1
+
+  # Run Ruff, our linter, against tb_pulumi
   lint:
     needs: detect-changes
     runs-on: ubuntu-latest
@@ -44,3 +71,17 @@ jobs:
         with:
           src: './tb_pulumi'
           args: 'format --check'
+
+  # Cut a new branch if there isn't one with this version number
+  # cut-version-branch:
+  #   needs: detect-versions
+  #   runs-on: ubuntu-latest
+  #   permissions:
+  #     contents: write
+  #   if: needs.detect-versions.outputs.branch-exists == 'false'
+  #   steps:
+  #     - name: Create a new version branch
+  #       uses: peterjgrainger/[email protected]
+  #       with:
+  #         branch: ${{ needs.detect-versions.outputs.version }}
+  #         sha: ${{ github.event.pull_request.head.sha }}