From 2df9a4b9db44ae831562c7fc2f7753fe2764731f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Joaqu=C3=ADn=20S=C3=A1nchez?= <userquin@gmail.com>
Date: Sun, 30 Jul 2023 20:47:29 +0200
Subject: [PATCH] fix(nuxt): test `watch` paths against all layer `srcDir`s
 (#22307)

---
 packages/nuxt/src/core/nuxt.ts       | 11 ++++++++---
 packages/schema/src/config/common.ts |  5 +++--
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/packages/nuxt/src/core/nuxt.ts b/packages/nuxt/src/core/nuxt.ts
index 9aa9a65dfc..5654f56572 100644
--- a/packages/nuxt/src/core/nuxt.ts
+++ b/packages/nuxt/src/core/nuxt.ts
@@ -1,4 +1,4 @@
-import { join, normalize, resolve } from 'pathe'
+import { join, normalize, relative, resolve } from 'pathe'
 import { createDebugger, createHooks } from 'hookable'
 import type { LoadNuxtOptions } from '@nuxt/kit'
 import { addBuildPlugin, addComponent, addPlugin, addVitePlugin, addWebpackPlugin, installModule, loadNuxtConfig, logger, nuxtCtx, resolveAlias, resolveFiles, resolvePath, tryResolveModule, useNitro } from '@nuxt/kit'
@@ -349,12 +349,17 @@ async function initNuxt (nuxt: Nuxt) {
     }
 
     // User provided patterns
+    const layerRelativePaths = nuxt.options._layers.map(l => relative(l.config.srcDir || l.cwd, path))
     for (const pattern of nuxt.options.watch) {
       if (typeof pattern === 'string') {
-        if (pattern === path) { return nuxt.callHook('restart') }
+        // Test (normalised) strings against absolute path and relative path to any layer `srcDir`
+        if (pattern === path || layerRelativePaths.includes(pattern)) { return nuxt.callHook('restart') }
         continue
       }
-      if (pattern.test(path)) { return nuxt.callHook('restart') }
+      // Test regular expressions against path to _any_ layer `srcDir`
+      if (layerRelativePaths.some(p => pattern.test(p))) {
+        return nuxt.callHook('restart')
+      }
     }
 
     // Core Nuxt files: app.vue, error.vue and app.config.ts
diff --git a/packages/schema/src/config/common.ts b/packages/schema/src/config/common.ts
index d5801081f2..80df36c583 100644
--- a/packages/schema/src/config/common.ts
+++ b/packages/schema/src/config/common.ts
@@ -365,8 +365,9 @@ export default defineUntypedSchema({
   /**
    * The watch property lets you define patterns that will restart the Nuxt dev server when changed.
    *
-   * It is an array of strings or regular expressions, which will be matched against the file path
-   * relative to the project `srcDir`.
+   * It is an array of strings or regular expressions. Strings should be either absolute paths or
+   * relative to the `srcDir` (and the `srcDir` of any layers). Regular expressions will be matched
+   * against the path relative to the project `srcDir` (and the `srcDir` of any layers).
    *
    * @type {Array<string | RegExp>}
    */