fix(is-parenthesized): don't crash on Program (mysticatea#31)

Author: fisker

src/is-parenthesized.js

@@ -94,6 +94,8 @@ export function isParenthesized(
 
     if (
         node == null ||
+        // `Program` can't be parenthesized
+        node.parent == null ||
         // `CatchClause.param` can't be parenthesized, example `try {} catch (error) {}`
         (node.parent.type === "CatchClause" && node.parent.param === node)
     ) {

test/is-parenthesized.js

@@ -209,6 +209,12 @@ describe("The 'isParenthesized' function", () => {
                 "body.0.handler.param": false,
             },
         },
+        {
+            code: "foo;",
+            expected: {
+                "body.0.parent": false,
+            },
+        },
     ]) {
         describe(`on the code \`${code}\``, () => {
             for (const key of Object.keys(expected)) {