Use filter instead of if statement

Author: mrmckeb

packages/react-scripts/scripts/utils/verifyPackageTree.js

@@ -19,7 +19,7 @@ const isESLintPluginEnabled = process.env.DISABLE_ESLINT_PLUGIN !== 'true';
 // in the tree will likely break your setup.
 // This is a relatively low-effort way to find common issues.
 function verifyPackageTree() {
-  let depsToCheck = [
+  const depsToCheck = [
     // These are packages most likely to break in practice.
     // See https://github.com/facebook/create-react-app/issues/1795 for reasons why.
     // I have not included Babel here because plugins typically don't import Babel (so it's not affected).
@@ -28,11 +28,8 @@ function verifyPackageTree() {
     'jest',
     'webpack',
     'webpack-dev-server',
-  ];
-
-  if (isESLintPluginEnabled) {
-    depsToCheck = [...depsToCheck, 'babel-eslint', 'eslint'];
-  }
+    ...(isESLintPluginEnabled && ['babel-eslint', 'eslint']),
+  ].filter(Boolean);
 
   // Inlined from semver-regex, MIT license.
   // Don't want to make this a dependency after ejecting.