feat: support eslint v9 flat config in plugin

.changeset/rich-peaches-punch.md

@@ -0,0 +1,5 @@
+---
+"@intlify/eslint-plugin-svelte": minor
+---
+
+feat: support eslint v9 flat config in plugin

.eslintrc.js

@@ -127,6 +127,10 @@ module.exports = {
       files: ['**/*.md/*.*'],
       rules: {
         'prettier/prettier': 'off'
+      },
+      parserOptions: {
+        ecmaVersion: 2021,
+        sourceType: 'module'
       }
     }
   ]

docs/rules/README.md

@@ -1,6 +1,6 @@
 # Available Rules
 
-- :star: mark: the rule which is enabled by `plugin:@intlify/svelte/recommended` preset.
+- :star: mark: the rule which is enabled by the `plugin:@intlify/svelte/recommended` or `*.configs.["flat/recommended"]` preset.
 - :black_nib: mark: the rule which is fixable by `eslint --fix` command.
 
 ## Recommended

docs/rules/no-raw-text.md

@@ -8,7 +8,7 @@ since: v0.0.1
 
 > disallow to string literal in template
 
-- :star: The `"extends": "plugin:@intlify/svelte/recommended"` property in a configuration file enables this rule.
+- :star: The `"extends": "plugin:@intlify/svelte/recommended"` or `*.configs["flat/recommended"]` property in a configuration file enables this rule.
 
 This rule warns the usage of string literal.
 

docs/started.md

@@ -17,11 +17,47 @@ npm install --save-dev eslint @intlify/eslint-plugin-svelte
 
 ## :rocket: Usage
 
-### Configuration
+### Configuration `eslint.config.[c|m]js`
 
-Configure your `.eslintrc.*` file.
+In ESLint v9, the the default way to configure files is using an `eslint.config.[c|m]js` file, but this can be used starting from ESLint v8.57.0.
 
-For example:
+See also: https://eslint.org/docs/latest/use/configure/configuration-files-new.
+
+Example `eslint.config.js`:
+
+```js
+import intlifySvelte from '@intlify/eslint-plugin-svelte'
+
+export default [
+  // add more generic rulesets here, such as:
+  //...eslintPluginSvelte.configs["flat/recommended"],
+
+  // Recommended
+  ...intlifySvelte.configs['flat/recommended'],
+  {
+    rules: {
+      // override/add rules settings here, such as:
+      '@intlify/svelte/no-raw-text': 'error'
+    }
+  }
+]
+```
+
+See [the rule list](./rules/README.md)
+
+#### Bundle Configurations `eslint.config.[c|m]js`
+
+This plugin provides some predefined configs. You can use the following configs by adding them to `eslint.config.[c|m]js`. (All flat configs in this plugin are provided as arrays, so spread syntax is required when combining them with other configs.)
+
+- `*configs["flat/base"]`: Settings and rules to enable correct ESlint parsing.
+- `*configs["flat/recommended"]`: Above, plus rules to enforce subjective community defaults to ensure consistency.
+
+### Configuration `.eslintrc.*`
+
+Use the `.eslintrc.*` file to configure rules in ESLint < v9. See also:
+https://eslint.org/docs/latest/use/configure/.
+
+Example `.eslintrc.js`:
 
 ```js
 module.export = {
@@ -44,6 +80,13 @@ module.export = {
 
 See [the rule list](./rules/README.md)
 
+#### Bundle Configurations `eslintrc.*`
+
+This plugin provides some predefined configs. You can use the following configs by adding them to `eslintrc.*`.
+
+- `plugin:@intlify/svelte/base`: Settings and rules to enable correct ESlint parsing.
+- `plugin:@intlify/svelte/recommended`: Above, plus rules to enforce subjective community defaults to ensure consistency.
+
 ::: warning ❗ Attention
 
 The `@intlify/eslint-plugin-svelte` can not be used with the [eslint-plugin-svelte3].

lib/configs/flat/base.ts

@@ -0,0 +1,18 @@
+/** DON'T EDIT THIS FILE; was created by scripts. */
+export = [
+  {
+    name: '@intlify/vue-i18n:base:setup',
+    plugins: {
+      get '@intlify/svelte'() {
+        return require('../../index')
+      }
+    }
+  },
+  {
+    name: '@intlify/svelte:base:svelte',
+    files: ['*.svelte'],
+    languageOptions: {
+      parser: require('svelte-eslint-parser')
+    }
+  }
+]

lib/configs/flat/recommended.ts

@@ -0,0 +1,23 @@
+/** DON'T EDIT THIS FILE; was created by scripts. */
+import config from './base'
+export = [
+  ...config,
+  {
+    name: '@intlify/svelte:recommended:setup',
+    languageOptions: {
+      ecmaVersion: 2018,
+      sourceType: 'module',
+      parserOptions: {
+        ecmaFeatures: {
+          jsx: true
+        }
+      }
+    }
+  },
+  {
+    name: '@intlify/svelte:recommended:rules',
+    rules: {
+      '@intlify/svelte/no-raw-text': 'warn'
+    }
+  }
+]

lib/index.ts

@@ -2,12 +2,23 @@
  * @fileoverview ESLint plugin for internationalization with Svelte
  * @author Yosuke Ota
  */
-import configs from './configs'
+import legacyBase from './configs/base'
+import legacyRecommended from './configs/recommended'
+import flatBase from './configs/flat/base'
+import flatRecommended from './configs/flat/recommended'
 import rules from './rules'
 import * as meta from './meta'
 
 export = {
   meta,
-  configs,
+  // eslintrc configs
+  configs: {
+    base: legacyBase,
+    recommended: legacyRecommended,
+
+    // flat configs
+    'flat/base': flatBase,
+    'flat/recommended': flatRecommended
+  },
   rules
 }

scripts/update-docs-index.ts

@@ -37,7 +37,7 @@ writeFileSync(
   resolve(__dirname, '../docs/rules/README.md'),
   `# Available Rules
 
-- :star: mark: the rule which is enabled by \`plugin:@intlify/svelte/recommended\` preset.
+- :star: mark: the rule which is enabled by the \`plugin:@intlify/svelte/recommended\` or \`*.configs.["flat/recommended"]\` preset.
 - :black_nib: mark: the rule which is fixable by \`eslint --fix\` command.
 
 ${withCategories

scripts/update-flat-base-config.ts

@@ -0,0 +1,25 @@
+import { resolve } from 'path'
+import { writeAndFormat } from './lib/write'
+
+writeAndFormat(
+  //base.ts
+  resolve(__dirname, '../lib/configs/flat/base.ts'),
+  `/** DON'T EDIT THIS FILE; was created by scripts. */
+  export = [
+    {
+      name: @intlify/svelte:base:setup',
+      plugins: {
+        get '@intlify/svelte'() {
+          return require('../../index')
+        }
+      }
+    },
+    {
+      name: "@intlify/svelte:base:svelte",
+      files: ['*.svelte'],
+      languageOptions: {
+          parser: require('svelte-eslint-parser'),
+      }
+    },
+  ]`
+)

scripts/update-flat-recommended-rules.ts

@@ -0,0 +1,34 @@
+import { resolve } from 'path'
+import rules from './lib/rules'
+import { writeAndFormat } from './lib/write'
+
+// flat/recommended.ts
+writeAndFormat(
+  resolve(__dirname, '../lib/configs/flat/recommended.ts'),
+  `/** DON'T EDIT THIS FILE; was created by scripts. */
+  import config from './base';
+  export = [
+    ...config,
+    {
+      name: '@intlify/svelte:recommended:setup',
+      languageOptions: {
+        ecmaVersion: 2018,
+        sourceType: 'module',
+        parserOptions: {
+          ecmaFeatures: {
+            jsx: true
+          }
+        }
+      }
+    },
+    {
+      name: '@intlify/svelte:recommended:rules',
+      rules: {
+        ${rules
+          .filter(rule => rule.recommended)
+          .map(rule => `'${rule.id}': 'warn',`)
+          .join('\n        ')}
+      },
+    }
+  ]`
+)

scripts/update-recommended-rules.ts → scripts/update-legacy-recommended-rules.ts

@@ -7,28 +7,28 @@ import { resolve } from 'path'
 import rules from './lib/rules'
 import { writeAndFormat } from './lib/write'
 
-// recommended.ts
+// legacy/recommended.ts
 writeAndFormat(
   resolve(__dirname, '../lib/configs/recommended.ts'),
   `/** DON'T EDIT THIS FILE; was created by scripts. */
-export = {
-  extends: [require.resolve('./base')],
-  parserOptions: {
-    ecmaVersion: 2018,
-    sourceType: 'module',
-    ecmaFeatures: {
-      jsx: true
-    }
-  },
-  env: {
-    browser: true,
-    es6: true
-  },
-  rules: {
-    ${rules
-      .filter(rule => rule.recommended)
-      .map(rule => `'${rule.id}': 'warn',`)
-      .join('\n        ')}
-  },
-}`
+  export = {
+    extends: [require.resolve('./base')],
+    parserOptions: {
+      ecmaVersion: 2018,
+      sourceType: 'module',
+      ecmaFeatures: {
+        jsx: true
+      }
+    },
+    env: {
+      browser: true,
+      es6: true
+    },
+    rules: {
+      ${rules
+        .filter(rule => rule.recommended)
+        .map(rule => `'${rule.id}': 'warn',`)
+        .join('\n        ')}
+    },
+  }`
 )

scripts/update-rule-docs.ts

@@ -90,7 +90,7 @@ async function updateRuleDocs(): Promise<void> {
         }
       } else if (rule.recommended) {
         headerLines.push(
-          '- :star: The `"extends": "plugin:@intlify/svelte/recommended"` property in a configuration file enables this rule.'
+          '- :star: The `"extends": "plugin:@intlify/svelte/recommended"` or `*.configs["flat/recommended"]` property in a configuration file enables this rule.'
         )
       }
 

scripts/update.ts

@@ -11,13 +11,14 @@ import './update-rule-docs'
 import './update-docs-index'
 
 // recommended rules.
-import './update-recommended-rules'
+import './update-legacy-recommended-rules'
+import './update-flat-recommended-rules'
+import './update-flat-base-config'
 import './update-meta'
 import { writeAndFormat } from './lib/write'
 
 // indices.
 for (const pairs of [
-  [resolve(__dirname, '../lib/configs')],
   [resolve(__dirname, '../lib/rules')]
   // [resolve(__dirname, '../lib/utils'), '', true]
 ] as const) {