Localize messages support

[azu]

stylelint support reporting custom message that is defined by user.

{
  "color-hex-case": [ "lower", {
    "message": "Lowercase letters are easier to distinguish from numbers"
  } ],
  "indentation": [ 2, {
    "ignore": ["block"],
    "message": "Please use 2 spaces for indentation. Tabs make The Architect grumpy.",
    "severity": "warning"
  } ]
}

• https://github.com/stylelint/stylelint/blob/master/docs/user-guide/configuration.md#custom-messages

This feature is needed for textlint.
Because, I know that textlint is used in some web application and software.
These application require "custome message" feature I think.

Can someone has implementation idea?

---

Update(2018-01-21):

Goal

Primary, We want to support following cases.

• Localize messages
  • textlint should have Internationalisation(i18n) system
• Custom messages by textlint application user
  • Application user can modify message
  • For example, an app that use textlint can customize report message.
• improve message test by textlint-tester
  • ESLint support that use messageIds for testing
• (Optional) Lint messages by textlint-tester
  • Lint error message
  • message should be start capitalized?
  • We want to prepare minimal pattern as recommendation

Optional(if it is as possibe)

• Localize document link
• Localization and Plurals

[azu]

I think that a casual User not needed custome message.
But, i18n/L10n message help user to read error message.

I propose that

• The user define your local like en-US, ja-JP in .textlintrc
  • If the local is not defined, use os-locale by default.
• textlint pass the locale information to a rule via context object
• The rule can localize message by the locale.
  • textlint-rule-helper help the localization.

It is very small start.

[azu]

📝 textlint will provide custom message by custom plugin/settings, maybe

{
    "localize":{
       "rule-a": {
          "message-id": "localized message"
       }
    },
    {
	"rules": {
    	    "rule-a": true
        }
    }
}

[azu]

markuplint has localize function.

• markuplint/index.ts at 0f66234b3be36312e008591c290aa2fe77337996 · YusukeHirao/markuplint

const message = await messages(locale, 'error');

[azu]

ESLint get messageId feature.

• https://eslint.org/docs/developer-guide/working-with-rules#messageids

It will help to localize message.

• Could we put lint messages in rule metadata? · Issue #6740 · eslint/eslint
• New: Add context.report({ messageId }) (fixes #6740) by j-f1 · Pull Request #9165 · eslint/eslint
• Proposal: locale option and meta.messages revision · Issue #9870 · eslint/eslint

[azu]

I have thought about it and meta data for rule.

src/
- textlint.meta.json
- rule.js

textlint.meta.json:

{
  "messages": {
     "id-a": "message a {key}",
     "id-b": {
       "ja": "メッセージ B",
       "en": "Message B"
      }
   }
}

rule.js:

const meta = require("./textlint.meta.json");
export default function(context) {
    const { RuleError, localize, report} = context;
    return {
        [context.Syntax.Str](node) {
            const message = localize(meta.messages["id-a"], { key: "value"});
            report(node, new RuleError(message));
        },
        [context.Syntax.Paragraph](node) {
            const message = localize(meta.messages["id-b"]);
            report(node, new RuleError(message));
        }
    };
};

Design

dependency flow:

rule.js explicitly depend on textlint.meta.json by design.
It allow to bundle a single file that include textlint.meta.json.
It is fit for browser.

meta file:

textlint.meta.json is separataed file.
It cab be written meta object for the rule.
Maybe, it is useful location for Options Schemas.
External application that include textlint can read textlint.meta.json without executing rule.js.

message format:
ICU formatter is better?

• Message Syntax — FormatJS
• intl-messageformat - npm
• Formatting Messages - ICU User Guide

https://github.com/messageformat/messageformat depended on Intl.

• https://caniuse.com/#feat=internationalization

And, Node.js does not support full-icu by default

• https://gfx.hatenablog.com/entry/2018/04/26/122959

Overlay:

Custom messages by textlint application user

application user can modify textlint.meta.json before to lint text by the rule.

Problem

This design is depended on location of textlint.meta.json.
Some rule use flat directory.

[azu]

Option Schema is related

[azu]

https://github.com/secretlint/secretlint/blob/master/docs/secretlint-rule.md
Secretlint implment messageId system.
It works and TypeSafe