fix(nitro): stop the v3 path importing the optional h3 peer

.changeset/fix-v3-h3-optional-peer-leak.md

@@ -0,0 +1,5 @@
+---
+"evlog": patch
+---
+
+Fix `evlog/nitro/v3` pulling in the optional `h3` peer. The v3 plugin shared a deferred-drain helper from the v2 module, which imports `getHeaders` from `h3`, so the v3 bundle referenced `h3` even though the v3 runtime never uses it. Consumers that don't install `h3` directly (e.g. Nitro v3 / TanStack Start on Vite) failed to build with `"getHeaders" is not exported by "__vite-optional-peer-dep:h3:evlog"`. The helper now lives in an h3-free module, so the v3 path no longer references `h3`.

packages/evlog/src/nitro-v3/plugin.ts

@@ -7,7 +7,7 @@
 import { readCodeSnippetFromDisk } from '../shared/pretty-error-snippet.node'
 import { enrichErrorStackForDev } from '../shared/enrich-error-stack.node'
 import { shouldLog, getServiceForPath, extractErrorStatus } from '../nitro'
-import { extendDeferredDrain } from '../nitro/enrich-drain'
+import { extendDeferredDrain } from '../nitro/deferred-drain'
 import { normalizeRedactConfig } from '../redact'
 import { resolveEvlogConfigForNitroPlugin, setActiveNitroRuntime } from '../shared/nitroConfigBridge'
 import { bindStreamingResponseLifecycle, shouldDeferEmitForResponse } from '../shared/streamResponse'
@@ -71,7 +71,7 @@
   }
 }
 
 async function callDrainHook(
   hooks: Hooks,
   emittedEvent: WideEvent | null,
   event: HTTPEvent,
@@ -124,7 +124,7 @@
   }
 }
 
 async function callEnrichAndDrain(
   hooks: Hooks,
   emittedEvent: WideEvent | null,
   event: HTTPEvent,

packages/evlog/src/nitro/deferred-drain.ts

@@ -0,0 +1,12 @@
+/** @internal Extend drain lifetime on Cloudflare without blocking Nitro Node responses. */
+export function extendDeferredDrain(
+  drainPromise: Promise<unknown>,
+  waitUntil?: (promise: Promise<unknown>) => void,
+): void {
+  void drainPromise.catch((err) => {
+    console.error('[evlog] background drain failed:', err)
+  })
+  if (typeof waitUntil === 'function') {
+    waitUntil(drainPromise)
+  }
+}

packages/evlog/src/nitro/enrich-drain.ts

@@ -3,6 +3,7 @@ import { getHeaders } from 'h3'
 import { getGlobalPluginRunner } from '../logger'
 import type { EnrichContext, ServerEvent, WideEvent } from '../types'
 import { filterSafeHeaders } from '../utils'
+import { extendDeferredDrain } from './deferred-drain'
 
 function getSafeHeaders(event: ServerEvent): Record<string, string> {
   const allHeaders = getHeaders(event as Parameters<typeof getHeaders>[0])
@@ -55,19 +56,6 @@ function buildHookContext(event: ServerEvent): Omit<EnrichContext, 'event'> {
   }
 }
 
-/** @internal Extend drain lifetime on Cloudflare without blocking Nitro Node responses. */
-export function extendDeferredDrain(
-  drainPromise: Promise<unknown>,
-  waitUntil?: (promise: Promise<unknown>) => void,
-): void {
-  void drainPromise.catch((err) => {
-    console.error('[evlog] background drain failed:', err)
-  })
-  if (typeof waitUntil === 'function') {
-    waitUntil(drainPromise)
-  }
-}
-
 function resolveDeferredWaitUntil(event: ServerEvent): ((promise: Promise<unknown>) => void) | undefined {
   if (globalThis.navigator?.userAgent !== 'Cloudflare-Workers') return undefined
   const waitUntilCtx = event.context.cloudflare?.context ?? event.context

packages/evlog/test/nitro-v3/h3-peer-isolation.test.ts

@@ -0,0 +1,64 @@
+import { existsSync, readFileSync } from 'node:fs'
+import { dirname, resolve } from 'node:path'
+import { describe, expect, it } from 'vitest'
+
+const v3Plugin = resolve(__dirname, '../../dist/nitro/v3/plugin.mjs')
+const distExists = existsSync(v3Plugin)
+
+if (!distExists) {
+  console.warn('[evlog test] Skipping h3 peer isolation: dist/ not found. Run `pnpm --filter evlog run build` first.')
+}
+
+// h3 is legitimately imported by the v2 runtime chunks, so it can't be forbidden
+// dist-wide. Collect the chunks the v3 plugin actually reaches (it pulls in
+// shared root-level chunks via `../../*.mjs`) and forbid h3 only within that set.
+function collectV3Chunks(entry: string): string[] {
+  const seen = new Set<string>()
+  const relativeRe = /(?:import|export)\s+(?:[^'"]*?\sfrom\s+)?['"](\.[^'"]+)['"]|import\s*\(\s*['"](\.[^'"]+)['"]\s*\)/g
+
+  const walk = (file: string): void => {
+    if (seen.has(file)) return
+    seen.add(file)
+    let source: string
+    try {
+      source = readFileSync(file, 'utf8')
+    } catch {
+      return
+    }
+    let match: RegExpExecArray | null
+    while ((match = relativeRe.exec(source))) {
+      walk(resolve(dirname(file), match[1] ?? match[2]))
+    }
+  }
+
+  walk(entry)
+  return [...seen]
+}
+
+/**
+ * Regression: the v3 plugin reused `extendDeferredDrain` from `nitro/enrich-drain`,
+ * which imports `getHeaders` from the optional `h3` peer for the v2 runtime. v3
+ * consumers without a direct `h3` dependency hit the stubbed optional peer and
+ * failed to build with `"getHeaders" is not exported by "__vite-optional-peer-dep:h3:evlog"`.
+ * No chunk in the v3 plugin's graph may import `h3`.
+ */
+describe.skipIf(!distExists)('evlog/nitro/v3 avoids the optional h3 peer', () => {
+  it('no chunk reachable from the v3 plugin imports h3', () => {
+    const chunks = collectV3Chunks(v3Plugin)
+    expect(chunks.length).toBeGreaterThan(0)
+
+    const forbidden = [
+      'from "h3"',
+      'from \'h3\'',
+      'import("h3")',
+      'import(\'h3\')',
+    ]
+
+    for (const file of chunks) {
+      const src = readFileSync(file, 'utf8')
+      for (const needle of forbidden) {
+        expect(src, file).not.toContain(needle)
+      }
+    }
+  })
+})