use esm

scripts/integration-tests/e2e-babel.sh

@@ -20,18 +20,21 @@ cd ../..
 #                                   TEST                                       #
 #==============================================================================#
 
-if [ "$BABEL_8_BREAKING" = true ] ; then
-  # This option is removed in Babel 8
-  sed -i 's/allowDeclareFields: true,\?/\/* allowDeclareFields: true *\//g' babel.config.js
-fi
-
 startLocalRegistry "$PWD"/scripts/integration-tests/verdaccio-config.yml
 
 # We only bump dependencies in the top-level package.json, because workspaces
 # already use the workspace: protocol so will get the version in the monorepo
 # and not from npm.
 node "$PWD"/scripts/integration-tests/utils/bump-babel-dependencies.js
 
+if [ "$BABEL_8_BREAKING" = true ] ; then
+  # This option is removed in Babel 8
+  sed -i 's/allowDeclareFields: true,\?/\/* allowDeclareFields: true *\//g' babel.config.js
+
+  # Babel 8 only supports ESM
+  make use-esm
+fi
+
 # Build and test
 YARN_ENABLE_IMMUTABLE_INSTALLS=false make -j test-ci