From feafa4c5f31487e784e221ec383451c40ef45370 Mon Sep 17 00:00:00 2001
From: Anthony Fu <anthonyfu117@hotmail.com>
Date: Tue, 24 May 2022 16:08:04 +0800
Subject: [PATCH] fix: improve dts writing to prevent loops

---
 playground/package.json |  3 ++-
 src/core/ctx.ts         | 41 ++++++++++++++++++++++++++++++++---------
 src/core/unplugin.ts    |  3 +++
 3 files changed, 37 insertions(+), 10 deletions(-)

diff --git a/playground/package.json b/playground/package.json
index c981560..ee26d16 100644
--- a/playground/package.json
+++ b/playground/package.json
@@ -1,7 +1,8 @@
 {
   "private": true,
   "scripts": {
-    "dev": "vite --open"
+    "dev": "vite --open",
+    "build": "vite build"
   },
   "dependencies": {
     "@vueuse/core": "^8.5.0",
diff --git a/src/core/ctx.ts b/src/core/ctx.ts
index 6baa6e4..2fdb2c5 100644
--- a/src/core/ctx.ts
+++ b/src/core/ctx.ts
@@ -4,6 +4,7 @@ import { slash, throttle, toArray } from '@antfu/utils'
 import { createFilter } from '@rollup/pluginutils'
 import { isPackageExists } from 'local-pkg'
 import type { Import } from 'unimport'
+// @ts-expect-error types
 import { vueTemplateAddon } from 'unimport/addons'
 import { createUnimport, scanDirExports } from 'unimport'
 import MagicString from 'magic-string'
@@ -73,12 +74,32 @@ export function createContext(options: Options = {}, root = process.cwd()) {
     })
   }
 
-  const writeConfigFiles = throttle(500, false, () => {
-    if (dts)
-      fs.writeFile(dts, generateDTS(dts), 'utf-8')
-    if (eslintrc.enabled && eslintrc.filepath)
-      fs.writeFile(eslintrc.filepath, generateESLintConfigs(unimport.getImports(), eslintrc), 'utf-8')
-  })
+  function generateESLint() {
+    return generateESLintConfigs(unimport.getImports(), eslintrc)
+  }
+
+  const writeConfigFilesThrottled = throttle(500, false, writeConfigFiles)
+
+  let lastDTS: string | undefined
+  let lastESLint: string | undefined
+  function writeConfigFiles() {
+    const promises: any[] = []
+    if (dts) {
+      const content = generateDTS(dts)
+      if (content !== lastDTS) {
+        lastDTS = content
+        promises.push(fs.writeFile(dts, generateDTS(dts), 'utf-8'))
+      }
+    }
+    if (eslintrc.enabled && eslintrc.filepath) {
+      const content = generateESLint()
+      if (content !== lastESLint) {
+        lastESLint = content
+        promises.push(fs.writeFile(eslintrc.filepath, content, 'utf-8'))
+      }
+    }
+    return Promise.all(promises)
+  }
 
   async function scanDirs() {
     if (dirs?.length) {
@@ -91,7 +112,7 @@ export function createContext(options: Options = {}, root = process.cwd()) {
         ] as Import[]
       })
     }
-    writeConfigFiles()
+    writeConfigFilesThrottled()
   }
 
   async function transform(code: string, id: string) {
@@ -102,7 +123,7 @@ export function createContext(options: Options = {}, root = process.cwd()) {
     if (!s.hasChanged())
       return
 
-    writeConfigFiles()
+    writeConfigFilesThrottled()
 
     return {
       code: s.toString(),
@@ -118,9 +139,11 @@ export function createContext(options: Options = {}, root = process.cwd()) {
     dirs,
     filter,
     scanDirs,
-    generateConfigFiles: writeConfigFiles,
+    writeConfigFiles,
+    writeConfigFilesThrottled,
     transform,
     generateDTS,
+    generateESLint,
   }
 }
 
diff --git a/src/core/unplugin.ts b/src/core/unplugin.ts
index 9f27f6b..9c855cc 100644
--- a/src/core/unplugin.ts
+++ b/src/core/unplugin.ts
@@ -16,6 +16,9 @@ export default createUnplugin<Options>((options) => {
     async buildStart() {
       await ctx.scanDirs()
     },
+    async buildEnd() {
+      await ctx.writeConfigFiles()
+    },
     vite: {
       async handleHotUpdate({ file }) {
         if (ctx.dirs?.some(dir => file.startsWith(dir)))