feat: add presubmit validation for generated types

Makefile

@@ -391,4 +391,14 @@ BILLING_ACCOUNT ?= 010E8D-490B6B-088E1C
 operator-e2e-tests:
 	export TEST_ORG_ID=${ORG_ID}
 	export TEST_BILLING_ACCOUNT_ID=${BILLING_ACCOUNT}
-	cd operator/tests/e2e/ && go test --project-id=${PROJECT_ID}
+	cd operator/tests/e2e/ && go test --project-id=${PROJECT_ID}
+
+# Generate Go types for direct resources specified in the config files located under `dev/tools/controllerbuilder/config`.
+.PHONY: generate-types
+generate-types:
+	cd dev/tools/controllerbuilder && \
+	./generate-proto.sh && \
+	for config in config/*.yaml; do \
+		go run . generate-types --config $$config; \
+	done
+	dev/tasks/fix-gofmt 

scripts/validate-prereqs.sh

@@ -93,3 +93,18 @@ if [[ "${changed_file_count}" != "0" ]] || [[ "${added_reference_doc_file_count}
     git ls-files --others --exclude-standard scripts/generate-google3-docs/resource-reference/generated/
     exit 1
 fi
+
+### This check ensures that the generated Go types for direct resources are not manually modified by accident.
+### Ensures that the code generation tools can be safely re-run.
+make generate-types
+changed_file_count=$(git diff --name-only | wc -l)
+if [[ "${changed_file_count}" != "0" ]]; then
+    echo "Full diff:"
+    git diff
+    echo "ERROR: The generated types are outdated. Run 'make generate-types' to update them."
+    echo "If you need to modify any types, first move them out of the generated file."
+    echo "Then run 'make generate-types' again to ensure the generated file remains unchanged."
+    echo "Affected files:"
+    git diff --name-only
+    exit 1
+fi