diff --git a/other-packages/eslint-config-saber/index.js b/other-packages/eslint-config-saber/index.js
index 2a1aee8d7..8191e3b73 100644
--- a/other-packages/eslint-config-saber/index.js
+++ b/other-packages/eslint-config-saber/index.js
@@ -36,6 +36,7 @@ module.exports = {
           requireLast: false
         }
       }
-    ]
+    ],
+    '@typescript-eslint/prefer-includes': 'off'
   }
 }
diff --git a/packages/saber/src/Compiler.ts b/packages/saber/src/Compiler.ts
index b939b1711..0ffdf4063 100644
--- a/packages/saber/src/Compiler.ts
+++ b/packages/saber/src/Compiler.ts
@@ -17,6 +17,7 @@ export class Compiler extends EventEmitter {
 
   injectToWebpack(config: WebpackChain) {
     const ID = `compiler-${this.type}`
+    // eslint-disable-next-line @typescript-eslint/no-this-alias
     const context = this
     config.plugin(ID).use(
       class {
diff --git a/packages/saber/src/plugins/config-css.js b/packages/saber/src/plugins/config-css.js
index 2d934785b..3d0e8f8be 100644
--- a/packages/saber/src/plugins/config-css.js
+++ b/packages/saber/src/plugins/config-css.js
@@ -150,7 +150,7 @@ exports.apply = api => {
               name: 'styles',
               // necessary to ensure async chunks are also extracted
               test: m => {
-                return /css\/mini-extract/.test(m.type)
+                return m.type && m.type.includes('css/mini-extract')
               },
               chunks: 'all',
               enforce: true
diff --git a/packages/saber/src/plugins/emit-runtime-polyfills.js b/packages/saber/src/plugins/emit-runtime-polyfills.js
index a5289ef85..7a8d76dd8 100644
--- a/packages/saber/src/plugins/emit-runtime-polyfills.js
+++ b/packages/saber/src/plugins/emit-runtime-polyfills.js
@@ -18,6 +18,7 @@ exports.apply = api => {
           polyfills,
           'utf8'
         )
+        // eslint-disable-next-line require-atomic-updates
         previousPolyfills = polyfills
       }
     })
diff --git a/packages/saber/src/plugins/extend-browser-api.js b/packages/saber/src/plugins/extend-browser-api.js
index 43ad66135..e608fd9d9 100644
--- a/packages/saber/src/plugins/extend-browser-api.js
+++ b/packages/saber/src/plugins/extend-browser-api.js
@@ -24,14 +24,20 @@ exports.apply = api => {
         cwd: api.resolveCwd(),
         ignoreInitial: true
       })
+      const onAdd = async filename => {
+        api.browserApi.add(api.resolveCwd(filename))
+        await api.browserApi.reload()
+      }
+      const onRemove = async filename => {
+        api.browserApi.delete(api.resolveCwd(filename))
+        await api.browserApi.reload()
+      }
       watcher
-        .on('add', async filename => {
-          api.browserApi.add(api.resolveCwd(filename))
-          await api.browserApi.reload()
+        .on('add', filename => {
+          onAdd(filename)
         })
-        .on('unlink', async filename => {
-          api.browserApi.delete(api.resolveCwd(filename))
-          await api.browserApi.reload()
+        .on('unlink', filename => {
+          onRemove(filename)
         })
     }
   })
diff --git a/packages/saber/src/plugins/extend-node-api.js b/packages/saber/src/plugins/extend-node-api.js
index cdd087045..38e16e20c 100644
--- a/packages/saber/src/plugins/extend-node-api.js
+++ b/packages/saber/src/plugins/extend-node-api.js
@@ -4,6 +4,10 @@ const { log, colors } = require('saber-log')
 
 const ID = 'builtin:extend-node-api'
 
+function __noopHandler__(arg) {
+  return arg
+}
+
 exports.name = ID
 
 exports.apply = api => {
@@ -58,35 +62,38 @@ exports.apply = api => {
       }
     })
 
-    if (api.dev && !/node_modules/.test(nodeApiFile)) {
+    if (api.dev && !nodeApiFile.includes('node_modules')) {
+      const onChange = async action => {
+        updateNodeApi()
+        // Remove all child pages
+        api.pages.removeWhere(page => page.internal.parent)
+        await Promise.all(
+          [...api.pages.values()].map(async page => {
+            // Recreate the page
+            api.pages.createPage(page)
+            // A page has been created
+            await api.hooks.onCreatePage.promise(page)
+          })
+        )
+        // All pages are created
+        await api.hooks.onCreatePages.promise()
+        // Emit pages
+        await api.hooks.emitPages.promise()
+        // Emit route file
+        await api.hooks.emitRoutes.promise()
+        log.warn(
+          `${action[0].toUpperCase()}${action.substring(1)} ${nodeApiFile}`
+        )
+        // Because you might also update webpack config in saber-node.js
+        // Which we can't (?) automatically reload
+        log.warn(`You probably need to restart the server.`)
+      }
       require('chokidar')
         .watch(nodeApiFile, {
           ignoreInitial: true
         })
-        .on('all', async action => {
-          await updateNodeApi()
-          // Remove all child pages
-          api.pages.removeWhere(page => page.internal.parent)
-          await Promise.all(
-            [...api.pages.values()].map(async page => {
-              // Recreate the page
-              api.pages.createPage(page)
-              // A page has been created
-              await api.hooks.onCreatePage.promise(page)
-            })
-          )
-          // All pages are created
-          await api.hooks.onCreatePages.promise()
-          // Emit pages
-          await api.hooks.emitPages.promise()
-          // Emit route file
-          await api.hooks.emitRoutes.promise()
-          log.warn(
-            `${action[0].toUpperCase()}${action.substring(1)} ${nodeApiFile}`
-          )
-          // Because you might also update webpack config in saber-node.js
-          // Which we can't (?) automatically reload
-          log.warn(`You probably need to restart the server.`)
+        .on('all', action => {
+          onChange(action)
         })
     }
   }
@@ -94,7 +101,3 @@ exports.apply = api => {
   handleNodeApiFile(path.join(api.theme, 'saber-node.js'), 'theme-node-api')
   handleNodeApiFile(api.resolveCwd('saber-node.js'), 'user-node-api')
 }
-
-function __noopHandler__(arg) {
-  return arg
-}
diff --git a/packages/saber/src/plugins/layouts.js b/packages/saber/src/plugins/layouts.js
index c617a7bbe..0853f3b65 100644
--- a/packages/saber/src/plugins/layouts.js
+++ b/packages/saber/src/plugins/layouts.js
@@ -58,6 +58,25 @@ exports.apply = api => {
       const watchLayouts = (dir, layouts) => {
         const chokidar = require('chokidar')
 
+        const onRemoveDir = async dir => {
+          if (!dir) {
+            Object.keys(layouts).forEach(name => {
+              delete layouts[name]
+            })
+            await writeLayouts(themeLayouts, userLayouts)
+          }
+        }
+
+        const onAddLayout = async file => {
+          setLayout(layouts, path.join(dir, file))
+          await writeLayouts(themeLayouts, userLayouts)
+        }
+
+        const onRemoveLayout = async file => {
+          setLayout(layouts, path.join(dir, file), true)
+          await writeLayouts(themeLayouts, userLayouts)
+        }
+
         // Clear the layouts object when the layouts directory is removed
         chokidar
           .watch('.', {
@@ -68,30 +87,23 @@ exports.apply = api => {
             },
             ignoreInitial: true
           })
-          .on('unlinkDir', async dir => {
-            if (!dir) {
-              Object.keys(layouts).forEach(name => {
-                delete layouts[name]
-              })
-              await writeLayouts(themeLayouts, userLayouts)
-            }
+          .on('unlinkDir', dir => {
+            onRemoveDir(dir)
           })
 
         // Add/Remove layout components
         chokidar
           .watch('*.{vue,js}', { cwd: dir, ignoreInitial: true })
-          .on('add', async file => {
-            setLayout(layouts, path.join(dir, file))
-            await writeLayouts(themeLayouts, userLayouts)
+          .on('add', file => {
+            onAddLayout(file)
           })
-          .on('unlink', async file => {
-            setLayout(layouts, path.join(dir, file), true)
-            await writeLayouts(themeLayouts, userLayouts)
+          .on('unlink', file => {
+            onRemoveLayout(file)
           })
       }
 
       // No need to watch theme layouts if it's from an npm package
-      if (!/node_modules/.test(themeLayoutsDir)) {
+      if (!themeLayoutsDir.includes('node_modules')) {
         watchLayouts(themeLayoutsDir, themeLayouts)
       }
 
diff --git a/packages/saber/src/plugins/source-pages.js b/packages/saber/src/plugins/source-pages.js
index af1bfeb55..844c2d249 100644
--- a/packages/saber/src/plugins/source-pages.js
+++ b/packages/saber/src/plugins/source-pages.js
@@ -29,6 +29,7 @@ exports.apply = api => {
           .map(async file => {
             file.relative = file.path
             file.absolute = path.join(pagesDir, file.relative)
+            // eslint-disable-next-line require-atomic-updates
             file.content = await fs.readFile(file.absolute, 'utf8')
             log.verbose(`Found page`, colors.dim(file.absolute))
             return file
@@ -81,6 +82,7 @@ exports.apply = api => {
 
           log.verbose(`Emitting page ${outPath}`)
           await fs.outputFile(outPath, newContentHash, 'utf8')
+          // eslint-disable-next-line require-atomic-updates
           page.internal.saved = true
         })
       )
@@ -126,9 +128,15 @@ exports.apply = api => {
         await api.hooks.emitRoutes.promise()
       }
 
-      watcher.on('add', handler('add'))
-      watcher.on('unlink', handler('remove'))
-      watcher.on('change', handler('change'))
+      watcher.on('add', () => {
+        handler('add')
+      })
+      watcher.on('unlink', () => {
+        handler('remove')
+      })
+      watcher.on('change', () => {
+        handler('change')
+      })
     }
   })
 }
diff --git a/packages/saber/src/plugins/transformer-markdown.js b/packages/saber/src/plugins/transformer-markdown.js
index 624301fa1..4499898a2 100644
--- a/packages/saber/src/plugins/transformer-markdown.js
+++ b/packages/saber/src/plugins/transformer-markdown.js
@@ -1,32 +1,6 @@
 const ConfigChain = require('../config-chain')
 const resolvePackage = require('../utils/resolvePackage')
 
-exports.name = 'builtin:transformer-markdown'
-
-exports.apply = api => {
-  api.transformers.add('markdown', {
-    extensions: ['md'],
-    transform(page) {
-      const { frontmatter, body } = require('../utils/parseFrontmatter')(
-        page.content,
-        page.internal.absolute
-      )
-      Object.assign(page, frontmatter)
-      page.content = body
-      page.content = renderMarkdown(api, page)
-    },
-    getPageComponent(page) {
-      return `
-        <template>
-        <layout-manager>
-          ${page.content || ''}
-        </layout-manager>
-        </template>
-      `
-    }
-  })
-}
-
 function renderMarkdown(api, page) {
   const { configDir } = api
   const { markdown = {} } = api.config
@@ -113,3 +87,29 @@ function renderMarkdown(api, page) {
 
   return md.render(page.content, env)
 }
+
+exports.name = 'builtin:transformer-markdown'
+
+exports.apply = api => {
+  api.transformers.add('markdown', {
+    extensions: ['md'],
+    transform(page) {
+      const { frontmatter, body } = require('../utils/parseFrontmatter')(
+        page.content,
+        page.internal.absolute
+      )
+      Object.assign(page, frontmatter)
+      page.content = body
+      page.content = renderMarkdown(api, page)
+    },
+    getPageComponent(page) {
+      return `
+        <template>
+        <layout-manager>
+          ${page.content || ''}
+        </layout-manager>
+        </template>
+      `
+    }
+  })
+}
diff --git a/packages/saber/src/utils/assetsAttribute.ts b/packages/saber/src/utils/assetsAttribute.ts
index f12c076ec..0652a6950 100644
--- a/packages/saber/src/utils/assetsAttribute.ts
+++ b/packages/saber/src/utils/assetsAttribute.ts
@@ -6,7 +6,7 @@ import { slash, isAbsoluteUrl } from 'saber-utils'
  * When it's an absolute url or starting with `/`
  * `/path` is used to reference files in static folder
  */
-const isExternal = (str: string) => isAbsoluteUrl(str) || /^\//.test(str)
+const isExternal = (str: string) => isAbsoluteUrl(str) || str.startsWith('/')
 
 const MARK = '@@!!SABER_ASSET_MARK_e5968b9a!!@@'
 
@@ -42,7 +42,4 @@ const requireAssets = (str: string) =>
     return `require("${p1}")`
   })
 
-export {
-  prefixAssets,
-  requireAssets
-}
+export { prefixAssets, requireAssets }
diff --git a/packages/saber/src/utils/getPermalink.js b/packages/saber/src/utils/getPermalink.js
index 41ee8ca88..4725df4a3 100644
--- a/packages/saber/src/utils/getPermalink.js
+++ b/packages/saber/src/utils/getPermalink.js
@@ -1,5 +1,13 @@
 // @ts-check
 
+/**
+ * Left-pad '0' to number that is smaller than 10
+ * @param {number} input
+ */
+function padZero(input) {
+  return input < 10 ? `0${input}` : input
+}
+
 // Default:
 // about.md => /about.html
 // about/index.md => /about
@@ -54,11 +62,3 @@ module.exports = (localeNames, page, permalinks) => {
     .replace(/^\/index(\.html)?$/, '/')
     .replace(/\/index(\.html)?$/, '')
 }
-
-/**
- * Left-pad '0' to number that is smaller than 10
- * @param {number} input
- */
-function padZero(input) {
-  return input < 10 ? `0${input}` : input
-}
diff --git a/packages/saber/src/utils/serveDir.js b/packages/saber/src/utils/serveDir.js
index f6e9bcde7..60761cf42 100644
--- a/packages/saber/src/utils/serveDir.js
+++ b/packages/saber/src/utils/serveDir.js
@@ -7,7 +7,7 @@ const serveStatic = require('serve-static')
 module.exports = function({ dir, host, port } = {}) {
   const server = polka()
   server.use(serveStatic(dir))
-  server.use(async (req, res, next) => {
+  server.use((req, res, next) => {
     if (req.method !== 'GET') return next()
     createReadStream(path.join(dir, '404.html')).pipe(res)
   })
diff --git a/packages/saber/src/vue-renderer/index.js b/packages/saber/src/vue-renderer/index.js
index e5e8a039e..f8e84a470 100644
--- a/packages/saber/src/vue-renderer/index.js
+++ b/packages/saber/src/vue-renderer/index.js
@@ -5,10 +5,27 @@ const { SyncWaterfallHook } = require('tapable')
 const { readJSON } = require('./utils')
 const renderHTML = require('./render-html')
 
+function runCompiler(compiler) {
+  return new Promise((resolve, reject) => {
+    compiler.run((err, stats) => {
+      if (err) return reject(err)
+      resolve(stats)
+    })
+  })
+}
+
 function resolveVueApp(...args) {
   return path.join(__dirname, '../../vue-app', ...args)
 }
 
+function removeTrailingSlash(input) {
+  if (input === '/') {
+    return input
+  }
+
+  return input.replace(/\/$/, '')
+}
+
 const ID = 'vue-renderer'
 
 export class VueRenderer {
@@ -476,6 +493,7 @@ export class VueRenderer {
     })
 
     server.get('/_saber/visit-page', async (req, res) => {
+      // eslint-disable-next-line
       let [, pathname, hash] = /^([^#]+)(#.+)?$/.exec(req.query.route) || []
       pathname = removeTrailingSlash(pathname)
       const fullPath = pathname + (hash || '')
@@ -565,20 +583,3 @@ export class VueRenderer {
     return server.handler
   }
 }
-
-function runCompiler(compiler) {
-  return new Promise((resolve, reject) => {
-    compiler.run((err, stats) => {
-      if (err) return reject(err)
-      resolve(stats)
-    })
-  })
-}
-
-function removeTrailingSlash(input) {
-  if (input === '/') {
-    return input
-  }
-
-  return input.replace(/\/$/, '')
-}