textlintをnode.jsで動かす #Node.js

$ mkdir textlint-test
$ cd textlint-test
$ npm init --yes
$ npm install --save-dev textlint
$ npm install --save-dev textlint-rule-no-todo
$ npm install --save-dev textlint-rule-max-kanji-continuous-len
$ npm install --save-dev express
$ npm install --save-dev ejs
$ npm install --save-dev cors
$ mkdir views

app.js

// vim:set ts=2 et:
// https://qiita.com/chenglin/items/5e563e50d1c32dadf4c3 express.jsのcors対応
const TextLintEngine = require('textlint').TextLintEngine;
const express = require('express');
const cors = require('cors')
const bodyParser = require('body-parser');
const app = express();

// 他からAPIリクエストできるように許可
app.set("view engine", "ejs");

// postデータのjsonをパースするおまじない
app.use(bodyParser.urlencoded({
    extended: true
}));
app.use(bodyParser.json());

// allow cors
app.use(cors());

// 18080番ポートで待ちうける
app.listen(18080, () => {
    console.log('Running at Port 18080...');
});

//app.post('/api/request', (req, res, next) => {
app.post(['/api/request', '/textlint/api/request'], (req, res, next) => {
    const req_text = req.body.text;
    const options = {
      rules: [
        "no-todo",
        "max-kanji-continuous-len",
      ],
      rulesConfig: {
        "no-todo": true,
        "max-kanji-continuous-len": true,
      },
    };
    const engine = new TextLintEngine(options);
    engine.executeOnText(req_text).then(results => {
        res.json({
            messages: results[0].messages
        });
    });
});

app.get("/", function (req, res) {
  res.render("index.ejs");
});

// その他のリクエストに対する404エラー
app.use((req, res) => {
    var url = req.protocol + '://' + req.headers.host + req.url;
    console.log(url);
    res.sendStatus(404);
});

index.ejs

<!DOCTYPE html>
<html lang="ja">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css"
          integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">
    <script src="https://code.jquery.com/jquery-3.3.1.min.js"
        integrity="sha256-FgpCb/KJQlLNfOu91ta32o/NMZxltwRo8QtmkMRdAu8="
        crossorigin="anonymous"></script>
    <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"
        integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM"
        crossorigin="anonymous"></script>

</head>
<body>

<form>
<div class="form-group">
    <label for="lint_textarea">Example textarea</label>
    <textarea class="form-control" id="lint_textarea" rows="10" placeholder="Write something here..."></textarea>
    <button type="button" class="btn btn-primary" id="btn_lint">Save</button>
</div>
</form>

<div>
      <p><strong>lint結果</strong><p>
      <ul id="textlint_output"></ul>
</div>

<script type="text/javascript">

(function () {
    'use strict';

    $('#btn_lint').on('click',function () {
        let text = $('#lint_textarea').val();
        let textData = JSON.stringify(
            {
                'text': text,
            });
        let textlint_url = location.protocol + "//" + location.host + "/textlint/api/request";
        $.ajax({
            type: 'POST',
            url: textlint_url,
            data: textData,
            contentType: 'application/json',
        }).done(function (data, textStatus, jqXHR) {
            // https://qiita.com/georgeOsdDev@github/items/34197e63d0fad307fba6
            $("#textlint_output").empty();
            let lines = text.split('\n');
            data.messages.forEach(function(m){
                let li = document.createElement('li');
                $(li).text(m.line + "行目" + m.column + "文字目 [" + m.ruleId + "]: <" + m.message + ">「" + lines[m.line -1] + "」")
                $("#textlint_output").append(li);
            });
        }).fail(function (jqXHR, textStatus, errorThrown) {
            console.log("failed");
        });
    });
}());
</script>

</body>
</html>

$ node app.js
Running at Port 18080...