Fix ESLint for K6

Author: alexeyr

.eslintrc

@@ -8,8 +8,8 @@ extends:
   - prettier
 
 globals:
-  __DEBUG_SERVER_ERRORS__: true
-  __SERVER_ERRORS__: true
+  __DEBUG_SERVER_ERRORS__: writable
+  __SERVER_ERRORS__: writable
 
 parserOptions:
   # We have @babel/eslint-parser from eslint-config-shakacode, but don't use Babel in the main project
@@ -77,3 +77,23 @@ overrides:
     rules:
       # Allows Jest mocks before import
       import/first: off
+  - files: "k6/**/*.{js,ts}"
+    globals:
+      # See https://github.com/grafana/k6-docs/blob/65d9f8a9a53f57a4f416763f8020d0c7f40eb976/docs/sources/.eslintrc.js
+      __ENV: readonly
+      __VU: readonly
+      __ITER: readonly
+      console: readonly
+      open: readonly
+      window: readonly
+      setInterval: readonly
+      clearInterval: readonly
+      setTimeout: readonly
+      clearTimeout: readonly
+    rules:
+      "import/extensions":
+        - error
+        - ignorePackages
+      "import/no-unresolved":
+        - error
+        - { ignore: ["k6.*"] }

k6/_util.js

@@ -2,7 +2,6 @@ export const url = (path) => `${__ENV.BASE_URL ?? "http://localhost:3000"}/${pat
 
 /** @type {(envVar: string) => boolean} */
 const envToBoolean = (envVar) => {
-// eslint-disable-next-line no-undef -- __ENV is provided by k6
   const value = __ENV[envVar];
   return !!value && ['true', '1', 'yes'].includes(value.toLowerCase());
 };

k6/root.js

@@ -1,7 +1,5 @@
-/* eslint-disable import/no-unresolved */
 import { check } from 'k6';
 import http from 'k6/http';
-/* eslint-enable import/no-unresolved */
 import { defaultOptions, url } from './_util.js';
 
 export const options = defaultOptions(false);