fix(oxc): tolerate stdout notices ahead of oxlint's JSON payload (#476)

* fix(oxc): tolerate stdout notices ahead of oxlint's JSON payload

Oxlint can print human-readable notices (e.g. "No files found to lint...")
to stdout before the JSON payload even when run with `-f json` — this
happens for any project where oxlint's default file discovery matches
zero files (e.g. a package that isn't opted into oxlint in a monorepo
with a default-deny root config). `parseOxlintOutput` called `JSON.parse`
on the raw stdout, so that leading notice broke parsing and the lint-run
RPC failed with "Oxlint returned invalid JSON" instead of reporting zero
diagnostics.

* fix(oxc): bridge RPC during local development

---------

Co-authored-by: yuyinws <lyc657508366@gmail.com>

Author: dvcolomban

packages/oxc/src/node/__tests__/lint-results.test.ts

@@ -106,3 +106,21 @@ it('accepts the null rule count emitted by recent oxlint versions', async () =>
     ),
   ).resolves.toMatchObject({ summary: { number_of_rules: null } })
 })
+
+it('skips the "no files found" notice oxlint prints to stdout ahead of the JSON payload', async () => {
+  const root = await createFixture()
+  const rawOutput = [
+    'No files found to lint. Please check your paths and ignore patterns.',
+    JSON.stringify({
+      diagnostics: [],
+      number_of_files: 0,
+      number_of_rules: 95,
+      threads_count: 11,
+      start_time: 0.03,
+    }),
+  ].join('\n')
+
+  await expect(parseOxlintOutput(rawOutput, root)).resolves.toMatchObject({
+    summary: { number_of_files: 0 },
+  })
+})

packages/oxc/src/node/utils/oxlint.ts

@@ -41,7 +41,14 @@ export async function ensureOxcGitignored(root: string) {
 }
 
 export async function parseOxlintOutput(rawOutput: string, root: string) {
-  const data = JSON.parse(rawOutput) as Record<string, unknown>
+  // Oxlint can print human-readable notices (e.g. "No files found to lint...") to stdout
+  // ahead of the JSON payload even in `-f json` mode. Skip to the first `{` so those notices
+  // don't break parsing.
+  const jsonStart = rawOutput.indexOf('{')
+  const data = JSON.parse(jsonStart === -1 ? rawOutput : rawOutput.slice(jsonStart)) as Record<
+    string,
+    unknown
+  >
   const summaryFields = [
     'number_of_files',
     'number_of_rules',

packages/oxc/src/nuxt.config.ts

@@ -1,6 +1,8 @@
 import { fileURLToPath } from 'node:url'
+import { viteDevBridge } from 'devframe/helpers/vite'
 import { defineNuxtConfig } from 'nuxt/config'
 import { alias } from '../../../alias'
+import { oxcDevframe } from './node/devframe'
 
 const BASE = '/__devtools-oxc/'
 
@@ -56,6 +58,9 @@ export default defineNuxtConfig({
   },
   vite: {
     base: BASE,
+    plugins: [
+      viteDevBridge({ ...oxcDevframe, basePath: '/' }, { base: BASE, devMiddleware: true }),
+    ],
     optimizeDeps: {
       include: ['modern-monaco', 'floating-vue'],
     },