From 73490437c42e5801c66314d0e6c5d12f16f5dec2 Mon Sep 17 00:00:00 2001
From: Kai Cataldo <kai@kaicataldo.com>
Date: Fri, 29 May 2020 16:33:56 -0400
Subject: [PATCH] chore: check version lazily in babel-eslint-parser

---
 eslint/babel-eslint-parser/src/index.js | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/eslint/babel-eslint-parser/src/index.js b/eslint/babel-eslint-parser/src/index.js
index bc140f09a8f8..2da046b0f05f 100644
--- a/eslint/babel-eslint-parser/src/index.js
+++ b/eslint/babel-eslint-parser/src/index.js
@@ -1,6 +1,6 @@
 import semver from "semver";
 import {
-  version as CURRENT_BABEL_VERSION,
+  version as babelCoreVersion,
   parseSync as babelParse,
 } from "@babel/core";
 import packageJson from "../package.json";
@@ -12,17 +12,19 @@ import convert from "./convert";
 import analyzeScope from "./analyze-scope";
 import visitorKeys from "./visitor-keys";
 
-const SUPPORTED_BABEL_VERSION_RANGE =
-  packageJson.peerDependencies["@babel/core"];
-const IS_RUNNING_SUPPORTED_VERSION = semver.satisfies(
-  CURRENT_BABEL_VERSION,
-  SUPPORTED_BABEL_VERSION_RANGE,
-);
+let isRunningSupportedVersion;
 
 function baseParse(code, options) {
-  if (!IS_RUNNING_SUPPORTED_VERSION) {
+  if (typeof isRunningSupportedVersion !== "boolean") {
+    isRunningSupportedVersion = semver.satisfies(
+      babelCoreVersion,
+      packageJson.peerDependencies["@babel/core"],
+    );
+  }
+
+  if (!isRunningSupportedVersion) {
     throw new Error(
-      `babel-eslint@${packageJson.version} does not support @babel/core@${CURRENT_BABEL_VERSION}. Please downgrade to babel-eslint@^10 or upgrade to @babel/core@${SUPPORTED_BABEL_VERSION_RANGE}`,
+      `@babel/eslint-parser@${packageJson.version} does not support @babel/core@${babelCoreVersion}. Please upgrade to @babel/core@${packageJson.peerDependencies["@babel/core"]}`,
     );
   }