From 77f6dccef731a76dc1d7123972c2a84281efd8ca Mon Sep 17 00:00:00 2001
From: likui <2218301630@qq.com>
Date: Tue, 26 May 2020 14:54:45 +0800
Subject: [PATCH 1/2] feat: skip unused json watch apply

---
 src/node/server/serverPluginJson.ts | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/src/node/server/serverPluginJson.ts b/src/node/server/serverPluginJson.ts
index ded1adfe199f32..5840a867efb045 100644
--- a/src/node/server/serverPluginJson.ts
+++ b/src/node/server/serverPluginJson.ts
@@ -1,14 +1,30 @@
 import { ServerPlugin } from '.'
 import { readBody, isImportRequest } from '../utils'
 
-export const jsonPlugin: ServerPlugin = ({ app }) => {
+const usedJsonSet = new Set<string>()
+
+export const jsonPlugin: ServerPlugin = ({ app, resolver, watcher }) => {
   app.use(async (ctx, next) => {
     await next()
     // handle .json imports
     // note ctx.body could be null if upstream set status to 304
-    if (ctx.path.endsWith('.json') && isImportRequest(ctx) && ctx.body) {
-      ctx.type = 'js'
-      ctx.body = `export default ${await readBody(ctx.body)}`
+    if (ctx.path.endsWith('.json')) {
+      if (isImportRequest(ctx) && ctx.body) {
+        ctx.type = 'js'
+        ctx.body = `export default ${await readBody(ctx.body)}`
+      }
+      usedJsonSet.add(ctx.path)
+    }
+  })
+
+  watcher.on('change', (filePath) => {
+    if (filePath.endsWith('.json')) {
+      const publicPath = resolver.fileToRequest(filePath)
+
+      // skip unused
+      if (!usedJsonSet.has(publicPath)) return
+
+      watcher.handleJSReload(filePath)
     }
   })
 }

From b0601c33630f19ea4d98ff8524c9ebee07696fee Mon Sep 17 00:00:00 2001
From: likui <2218301630@qq.com>
Date: Tue, 26 May 2020 15:20:19 +0800
Subject: [PATCH 2/2] fix: skip check for json files

---
 src/node/server/serverPluginHmr.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/node/server/serverPluginHmr.ts b/src/node/server/serverPluginHmr.ts
index 385f9e9636dbe6..ad48ea17b822cb 100644
--- a/src/node/server/serverPluginHmr.ts
+++ b/src/node/server/serverPluginHmr.ts
@@ -183,6 +183,7 @@ export const hmrPlugin: ServerPlugin = ({
   watcher.on('change', (file) => {
     if (
       !(
+        file.endsWith('.json') ||
         file.endsWith('.vue') ||
         file.endsWith('.css') ||
         cssPreprocessLangRE.test(file)