Auto-resolve modal dependency overlay conflicts

.github/workflows/propagate.yml

@@ -29,6 +29,9 @@ jobs:
           fetch-depth: 0
           token: ${{ steps.create_token.outputs.token }}
 
+      - name: Install uv
+        uses: astral-sh/setup-uv@v4
+
       - name: Attempt merge and push, or open PR on conflict
         env:
           GH_TOKEN: ${{ steps.create_token.outputs.token }}
@@ -37,16 +40,7 @@ jobs:
           git config user.name "github-actions[bot]"
           git config user.email "github-actions[bot]@users.noreply.github.com"
 
-          git checkout "$BRANCH"
-
-          if git merge origin/main --no-edit; then
-            echo "Merge succeeded, pushing to $BRANCH"
-            git push origin "$BRANCH"
-          else
-            echo "Merge conflict detected, opening PR"
-            git merge --abort
-
-            # Create a temporary branch for the PR
+          open_propagation_pr() {
             TEMP_BRANCH="auto-merge/main-to-${BRANCH}-$(date +%Y%m%d%H%M%S)"
             git checkout -b "$TEMP_BRANCH" origin/main
 
@@ -64,4 +58,120 @@ jobs:
           🤖 Generated by the propagate workflow
           PREOF
               )"
+          }
+
+          unresolved_conflicts() {
+            git diff --name-only --diff-filter=U | sort
+          }
+
+          conflicts_are_modal_overlay() {
+            [ "$BRANCH" = "modal" ] || return 1
+
+            conflicts="$(unresolved_conflicts)"
+            [ -n "$conflicts" ] || return 1
+
+            while IFS= read -r file; do
+              case "$file" in
+                pyproject.toml|uv.lock) ;;
+                *) return 1 ;;
+              esac
+            done <<< "$conflicts"
+          }
+
+          add_modal_dependency() {
+            python3 <<'PY'
+          from pathlib import Path
+          import subprocess
+          import tomllib
+
+          def is_modal_dependency(dependency: str) -> bool:
+              return dependency.split(";", 1)[0].strip().lower().startswith("modal")
+
+
+          def modal_dependency_from_branch() -> str:
+              try:
+                  result = subprocess.run(
+                      ["git", "show", ":2:pyproject.toml"],
+                      check=True,
+                      capture_output=True,
+                      text=True,
+                  )
+              except subprocess.CalledProcessError:
+                  return "modal>=0.73.162"
+
+              dependencies = tomllib.loads(result.stdout).get("project", {}).get("dependencies", [])
+              return next((dependency for dependency in dependencies if is_modal_dependency(dependency)), "modal>=0.73.162")
+
+
+          path = Path("pyproject.toml")
+          text = path.read_text()
+          data = tomllib.loads(text)
+
+          dependencies = data.get("project", {}).get("dependencies", [])
+          if any(is_modal_dependency(dependency) for dependency in dependencies):
+              raise SystemExit(0)
+
+          lines = text.splitlines()
+          start = next(
+              (index for index, line in enumerate(lines) if line.strip() == "dependencies = ["),
+              None,
+          )
+          if start is None:
+              raise SystemExit("Could not find project dependencies in pyproject.toml")
+
+          end = next(
+              (index for index in range(start + 1, len(lines)) if lines[index].strip() == "]"),
+              None,
+          )
+          if end is None:
+              raise SystemExit("Could not find end of project dependencies in pyproject.toml")
+
+          insert_at = end
+          for index in range(start + 1, end):
+              if lines[index].strip().startswith('"psycopg2-binary'):
+                  insert_at = index
+                  break
+
+          lines.insert(insert_at, f'    "{modal_dependency_from_branch()}",')
+          path.write_text("\n".join(lines) + "\n")
+          PY
+          }
+
+          resolve_modal_overlay() {
+            if unresolved_conflicts | grep -qx "pyproject.toml"; then
+              git checkout --theirs pyproject.toml
+            fi
+
+            add_modal_dependency
+
+            if unresolved_conflicts | grep -qx "uv.lock"; then
+              git checkout --ours uv.lock
+            fi
+
+            uv lock
+            git add pyproject.toml uv.lock
+
+            remaining_conflicts="$(unresolved_conflicts)"
+            if [ -n "$remaining_conflicts" ]; then
+              echo "Conflicts remain after modal overlay resolution:"
+              echo "$remaining_conflicts"
+              return 1
+            fi
+
+            git commit --no-edit
+            git push origin "$BRANCH"
+          }
+
+          git checkout "$BRANCH"
+
+          if git merge origin/main --no-edit; then
+            echo "Merge succeeded, pushing to $BRANCH"
+            git push origin "$BRANCH"
+          elif conflicts_are_modal_overlay; then
+            echo "Merge conflict only affects the modal dependency overlay; resolving automatically"
+            resolve_modal_overlay
+          else
+            echo "Merge conflict detected, opening PR"
+            git merge --abort
+            open_propagation_pr
           fi