tools: add support for import assertions in linter

PR-URL: #39924
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Bradley Farias <bradley.meck@gmail.com>
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Zijian Liu <lxxyxzj@gmail.com>

Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Geoffrey Booth <webadmin@geoffreybooth.com>

.eslintrc.js

@@ -17,6 +17,7 @@ const hacks = [
   'eslint-plugin-node-core',
   'eslint-plugin-markdown',
   '@babel/eslint-parser',
+  '@babel/plugin-syntax-import-assertions',
 ];
 Module._findPath = (request, paths, isMain) => {
   const r = ModuleFindPath(request, paths, isMain);
@@ -36,6 +37,11 @@ module.exports = {
   plugins: ['markdown', 'node-core'],
   parser: '@babel/eslint-parser',
   parserOptions: {
+    babelOptions: {
+      plugins: [
+        Module._findPath('@babel/plugin-syntax-import-assertions'),
+      ],
+    },
     requireConfigFile: false,
     sourceType: 'script',
   },

test/es-module/test-esm-import-assertion-1.mjs

@@ -0,0 +1,7 @@
+// Flags: --experimental-json-modules --harmony-import-assertions
+import '../common/index.mjs';
+import { strictEqual } from 'assert';
+
+import secret from '../fixtures/experimental.json' assert { type: 'json' };
+
+strictEqual(secret.ofLife, 42);