Ensure that the arrow nodes have a location before using them. (#9003)

2018-11-12 17:10:49 -08:00
parent 4fcee1751a
commit cbbb3c7962
1 changed files with 3 additions and 1 deletions
--- a/packages/babel-generator/src/generators/methods.js
+++ b/packages/babel-generator/src/generators/methods.js
@@ -113,10 +113,12 @@ export function ArrowFunctionExpression(node: Object) {
  ) {
    if (
      this.format.retainLines &&
+      node.loc &&
+      node.body.loc &&
      node.loc.start.line < node.body.loc.start.line
    ) {
      this.token("(");
-      if (firstParam.loc.start.line > node.loc.start.line) {
+      if (firstParam.loc && firstParam.loc.start.line > node.loc.start.line) {
        this.indent();
        this.print(firstParam, node);
        this.dedent();