feat: make the rule fixable (#4)

Author: takenspc

README.md

@@ -36,6 +36,18 @@ Via CLI
 textlint --rule no-hankaku-kana README.md
 ```
 
+## Fixable
+
+[![Textlint fixable](https://img.shields.io/badge/textlint-fixable-green.svg?style=social)](https://textlint.github.io/) 
+
+`textlint --fix` での自動修正に対応しています。
+
+*   NFCで表現できる濁点・半濁点はNFCに修正
+    *   例：ﾊﾟﾝﾀﾞはパンダに修正
+*   NFCで表現できない濁点・半濁点はNFDに修正
+    *   例：ｱﾞは[ア゙](https://ja.wikipedia.org/wiki/%E3%81%82%E3%82%99)に修正
+    *   例：ﾂﾟは[ツ゚](https://ja.wikipedia.org/wiki/%E3%83%84%E3%82%9C)に修正
+
 ## Changelog
 
 See [Releases page](https://github.com/textlint-ja/textlint-rule-no-hankaku-kana/releases).

src/textlint-rule-no-hankaku-kana.ts

@@ -6,7 +6,7 @@ import { TextlintRuleModule } from "@textlint/types";
 const HankakuRegExp = /([\uff61-\uff9f]+)/g;
 export type Options = {};
 export const report: TextlintRuleModule<Options> = function reporter(context) {
-    const { Syntax, RuleError, report, locator, getSource } = context;
+    const { Syntax, RuleError, fixer, report, locator, getSource } = context;
     const helper = new RuleHelper(context);
     return {
         [Syntax.Str](node) {
@@ -17,12 +17,17 @@ export const report: TextlintRuleModule<Options> = function reporter(context) {
             for (const match of nodeText.matchAll(HankakuRegExp)) {
                 const text = match[0];
                 const index = match.index ?? 0;
+                const range = [index, index + text.length] as const;
                 const ruleError = new RuleError(`Disallow to use 半角カタカナ: "${text}"`, {
-                    padding: locator.range([index, index + text.length])
+                    padding: locator.range(range),
+                    fix: fixer.replaceTextRange(range, text.normalize('NFKC')),
                 });
                 report(node, ruleError);
             }
         }
     }
 };
-export default report;
+export default {
+    linter: report,
+    fixer: report,
+};

test/textlint-rule-no-hankaku-kana-test.ts

@@ -16,6 +16,7 @@ tester.run("no-hankaku-kana", rule, {
     invalid: [
         {
             text: "ｶﾀｶﾅ",
+            output: "カタカナ",
             errors: [
                 {
                     message: `Disallow to use 半角カタカナ: "ｶﾀｶﾅ"`,
@@ -26,6 +27,7 @@ tester.run("no-hankaku-kana", rule, {
         // multiple hit items in a line
         {
             text: `ｶﾀｶﾅはゼンカクとﾊﾝｶｸがある`,
+            output: `カタカナはゼンカクとハンカクがある`,
             errors: [
                 {
                     message: `Disallow to use 半角カタカナ: "ｶﾀｶﾅ"`,
@@ -42,6 +44,7 @@ tester.run("no-hankaku-kana", rule, {
         // multiple match in multiple lines
         {
             text: "ｶﾀｶﾅ\nﾊﾝｶｸ",
+            output: "カタカナ\nハンカク",
             errors: [
                 {
                     message: `Disallow to use 半角カタカナ: "ｶﾀｶﾅ"`,
@@ -71,6 +74,26 @@ tester.run("no-hankaku-kana", rule, {
                     }
                 }
             ]
-        }
+        },
+        {
+            text: `NFCで表現できる濁点・半濁点はNFCに修正する：ﾊﾟﾝﾀﾞ`,
+            output: `NFCで表現できる濁点・半濁点はNFCに修正する：パンダ`,
+            errors: [
+                {
+                    message: `Disallow to use 半角カタカナ: "ﾊﾟﾝﾀﾞ"`,
+                    range: [25, 30]
+                },
+            ]
+        },
+        {
+            text: `NFCで表現できない濁点・半濁点はNFDに修正する：ｱ\u{ff9e}ﾂ\u{ff9f}`,
+            output: `NFCで表現できない濁点・半濁点はNFDに修正する：ア\u{3099}ツ\u{309a}`,
+            errors: [
+                {
+                    message: `Disallow to use 半角カタカナ: "ｱ\u{ff9e}ﾂ\u{ff9f}"`,
+                    range: [26, 30]
+                },
+            ]
+        },
     ]
 });