chore: eslint config to prevent usage of import.meta.env.X without optional chaining or qTest

Author: maiieul

eslint.config.mjs

@@ -133,6 +133,64 @@ export default tseslint.config(
       'qwik-local/loop-style': 'error',
     },
   },
+  {
+    // Webpack-safety: every `import.meta.env.X` access must use optional chaining.
+    // Applies to both core and qwik-router source — non-Vite consumers ship both.
+    files: ['packages/qwik/src/**/*.{ts,tsx}', 'packages/qwik-router/src/**/*.{ts,tsx}'],
+    ignores: ['**/*.unit.*', '**/*.spec.*', '**/*.d.ts'],
+    rules: {
+      'no-restricted-syntax': [
+        'error',
+        {
+          selector:
+            "MemberExpression[object.type='MemberExpression']" +
+            "[object.object.type='MetaProperty']" +
+            "[object.property.name='env']" +
+            ':not([optional=true])',
+          message:
+            'Use `import.meta.env?.X` (optional chaining). Non-Vite consumers (webpack, ' +
+            'plain Node, etc.) ship our published bundles where `import.meta.env` is ' +
+            'undefined and `.X` access throws a TypeError.',
+        },
+      ],
+    },
+  },
+  {
+    // Test-mode gating: prefer the `qTest` const over `import.meta.env?.TEST`.
+    // Scoped to qwik core only. qwik-router source can't reach `qTest` (it's in core's
+    // internal `shared/utils/qdev`, not part of the public API), so this rule doesn't
+    // apply there — its `import.meta.env?.TEST` usage is intentional.
+    files: ['packages/qwik/src/**/*.{ts,tsx}'],
+    ignores: ['**/*.unit.*', '**/*.spec.*', '**/*.d.ts'],
+    rules: {
+      'no-restricted-syntax': [
+        'error',
+        {
+          selector:
+            "MemberExpression[object.type='MemberExpression']" +
+            "[object.object.type='MetaProperty']" +
+            "[object.property.name='env']" +
+            ':not([optional=true])',
+          message:
+            'Use `import.meta.env?.X` (optional chaining). Non-Vite consumers (webpack, ' +
+            'plain Node, etc.) ship our published bundles where `import.meta.env` is ' +
+            'undefined and `.X` access throws a TypeError.',
+        },
+        {
+          selector:
+            'MemberExpression[optional=true]' +
+            "[object.type='MemberExpression']" +
+            "[object.object.type='MetaProperty']" +
+            "[object.property.name='env']" +
+            "[property.name='TEST']",
+          message:
+            'Use the `qTest` const from `<...>/shared/utils/qdev` instead of ' +
+            '`import.meta.env?.TEST`. `qTest` reads `globalThis.qTest` (webpack-safe) AND ' +
+            'lets Terser fold it via `global_defs` for prod tree-shaking.',
+        },
+      ],
+    },
+  },
   {
     files: ['packages/qwik/src/server/**/*.ts'],
     ignores: ['packages/qwik/src/server/qwik-copy.ts'],