Chore: fail if >1 migration scripts start with the same version

Author: georgesittas

.pre-commit-config.yaml

@@ -23,3 +23,9 @@ repos:
         files: *files
         require_serial: true
         exclude: ^(tests/fixtures)
+      - id: check-migration-duplicates
+        name: Check migration duplicates
+        language: script
+        entry: ./scripts/check_migration_duplicates.sh
+        files: ^sqlmesh/migrations/v\d{4}_.*\.py$
+        pass_filenames: false

scripts/check_migration_duplicates.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+# Check for duplicate migration version numbers in SQLMesh
+
+# Extract version numbers from migration files and check for duplicates
+duplicates=$(ls sqlmesh/migrations/v[0-9][0-9][0-9][0-9]_*.py 2>/dev/null | \
+    sed 's/.*\/v\([0-9]\{4\}\)_.*/\1/' | \
+    sort | uniq -d)
+
+if [ -n "$duplicates" ]; then
+    echo "Error: Duplicate migration version(s) found:" >&2
+    for version in $duplicates; do
+        echo "  Version v$version appears in:" >&2
+        ls sqlmesh/migrations/v${version}_*.py | sed 's/^/    - /' >&2
+    done
+    exit 1
+fi
+
+exit 0