diff --git a/.eslintrc.js b/.eslintrc.js
index 668fac4..818fa85 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -3,15 +3,11 @@ module.exports = {
     es6: true,
     node: true,
   },
-  extends: [
-    'google',
-  ],
   parserOptions: {
     ecmaVersion: 2018,
     sourceType: 'module',
   },
-  rules: {
-    'arrow-parens': ['error', 'as-needed'],
-    'indent': ['error', 2, {'MemberExpression': 1}],
-  },
+  extends: [
+    '@sup39/basic',
+  ],
 };
diff --git a/lib/index.js b/lib/index.js
index 98fb885..7e3fe4c 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -2,8 +2,10 @@ const {parseAttrs, attrConcat} = require('./utils.js');
 const {inlineAttrsApplyRules} = require('./rules.js');
 
 /**
- * @param {MarkdownIt} md
- * @param {{deliminator: string, re: RegExp}} opts
+ * @type {import('markdown-it').PluginWithOptions<{
+ *   deliminator?: string,
+ *   re?: RegExp,
+ * }>}
  */
 function pluginAttr(md, opts={}) {
   const deliminator = opts.deliminator || '{';
diff --git a/lib/rules.js b/lib/rules.js
index a7433b0..d05d1e4 100644
--- a/lib/rules.js
+++ b/lib/rules.js
@@ -1,7 +1,17 @@
+/**
+ * @typedef {import('markdown-it/lib/token')} Token
+ */
 const {
   findOpenToken, find, rfind, rfindIndex, attrConcat,
 } = require('./utils.js');
 
+/**
+ * @type {{
+ *   name: string
+ *   disabled?: boolean
+ *   handler(token: Token, i: number, tokens: Token[], iBlock: number, blockTokens: Token[]): void
+ * }[]}
+ */
 const inlineAttrsApplyRules = [
   {
     name: 'first_child',
@@ -22,9 +32,9 @@ const inlineAttrsApplyRules = [
   },
   {
     name: 'after_inline_block',
-    handler(token, i, tokens, iBlock, blockTokens) {
+    handler(token, i, tokens) {
       // find non-empty text token
-      const iC = rfindIndex(tokens, i-1, t=>t.type!=='text'||t.content);
+      const iC = rfindIndex(tokens, i-1, t=>t.type!=='text'||!!t.content);
       const tokenC = iC>=0 && tokens[iC];
       if (!tokenC) return;
       // check tokenC type
diff --git a/lib/utils.js b/lib/utils.js
index b6d167c..f26a66a 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -1,8 +1,12 @@
+/**
+ * @typedef {import('markdown-it/lib/token')} Token
+ */
+
 /**
  * @param {string} s - input string
  * @param {RegExp} re - regular expression for attributes
  * @param {number} [limit=65536] - limit of attribute count
- * @return {{attr: [string, string][]}|null}
+ * @return {{attrs: [string, string][], index: number}|null}
  */
 function parseAttrs(s, re, limit=65536) {
   let count = 0;
@@ -30,7 +34,7 @@ function parseAttrs(s, re, limit=65536) {
 }
 
 /**
- * @param {Token} tokens - tokens
+ * @param {Token[]} tokens - tokens
  * @param {number} i - index of close token
  * @return {Token|null} - open token
  */
@@ -46,11 +50,12 @@ function findOpenToken(tokens, i) {
 }
 
 /**
- * @param {Array} arr
+ * @template T
+ * @param {T[]} arr
  * @param {number} startIndex
- * @param {function(any, number): boolean} test
- * @param {function(any, number): boolean} [constraint]
- * @return {any|undefined} element;
+ * @param {(elm: T) => boolean} test
+ * @param {(elm: T) => boolean} [constraint]
+ * @return {T|undefined} element;
  */
 function find(arr, startIndex, test, constraint=()=>true) {
   for (let i=startIndex, len=arr.length; i<len; i++) {
@@ -58,15 +63,15 @@ function find(arr, startIndex, test, constraint=()=>true) {
     if (!constraint(elm)) return;
     if (test(elm)) return elm;
   }
-  return;
 }
 
 /**
- * @param {Array} arr
+ * @template T
+ * @param {T[]} arr
  * @param {number} startIndex
- * @param {function(any, number): boolean} test
- * @param {function(any, number): boolean} [constraint]
- * @return {any|undefined} element;
+ * @param {(elm: T) => boolean} test
+ * @param {(elm: T) => boolean} [constraint]
+ * @return {T|undefined} element;
  */
 function rfind(arr, startIndex, test, constraint=()=>true) {
   for (let i=startIndex; i>=0; i--) {
@@ -74,14 +79,14 @@ function rfind(arr, startIndex, test, constraint=()=>true) {
     if (!constraint(elm)) return;
     if (test(elm)) return elm;
   }
-  return;
 }
 
 /**
- * @param {Array} arr
+ * @template T
+ * @param {T[]} arr
  * @param {number} startIndex
- * @param {function(any, number): boolean} test
- * @param {function(any, number): boolean} [constraint]
+ * @param {(elm: T) => boolean} test
+ * @param {(elm: T) => boolean} [constraint]
  * @return {number} index ?? -1;
  */
 function rfindIndex(arr, startIndex, test, constraint=()=>true) {
diff --git a/package.json b/package.json
index 7919471..4d71442 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@sup39/markdown-it-attr",
-  "version": "1.2.0",
+  "version": "1.2.1",
   "description": "A markdown-it plugin to write id, classes, and attributes",
   "keywords": [
     "markdown",
@@ -19,9 +19,9 @@
     "lib/"
   ],
   "devDependencies": {
+    "@sup39/eslint-config-basic": "^0.1.0",
     "@sup39/markdown-it-raw-table": "^1.0.0",
     "eslint": "^7.17.0",
-    "eslint-config-google": "^0.14.0",
     "markdown-it": "^12.0.4",
     "mocha": "^8.2.1"
   }
diff --git a/yarn.lock b/yarn.lock
index 03785d7..ce6d8d5 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -38,6 +38,11 @@
     minimatch "^3.0.4"
     strip-json-comments "^3.1.1"
 
+"@sup39/eslint-config-basic@^0.1.0":
+  version "0.1.0"
+  resolved "https://registry.yarnpkg.com/@sup39/eslint-config-basic/-/eslint-config-basic-0.1.0.tgz#4b445515ddf8e70766a7b790db1314c621829b39"
+  integrity sha512-+YJBNJ59T3WMAG5+M6zZJj341SfyCOlq3FuvUsZWy72ESKUCcMpl1LFUuy86K7iPeGGUs8Kex4f4EQrex1DBGg==
+
 "@sup39/markdown-it-raw-table@^1.0.0":
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/@sup39/markdown-it-raw-table/-/markdown-it-raw-table-1.0.0.tgz#a8de8f03df60cba9430cc1c3f011e0b0eb05bcf6"
@@ -312,11 +317,6 @@ escape-string-regexp@^1.0.5:
   resolved "https://registry.yarnpkg.com/escape-string-regexp/-/escape-string-regexp-1.0.5.tgz#1b61c0562190a8dff6ae3bb2cf0200ca130b86d4"
   integrity sha1-G2HAViGQqN/2rjuyzwIAyhMLhtQ=
 
-eslint-config-google@^0.14.0:
-  version "0.14.0"
-  resolved "https://registry.yarnpkg.com/eslint-config-google/-/eslint-config-google-0.14.0.tgz#4f5f8759ba6e11b424294a219dbfa18c508bcc1a"
-  integrity sha512-WsbX4WbjuMvTdeVL6+J3rK1RGhCTqjsFjX7UMSMgZiyxxaNLkoJENbrGExzERFeoTpGw3F3FypTiWAP9ZXzkEw==
-
 eslint-scope@^5.1.1:
   version "5.1.1"
   resolved "https://registry.yarnpkg.com/eslint-scope/-/eslint-scope-5.1.1.tgz#e786e59a66cb92b3f6c1fb0d508aab174848f48c"