feat: support non-js languages

eslint-plugin-prettier.js

@@ -12,6 +12,8 @@
  */
 
 /**
+ * @typedef {{ line: number; column: number; offset: number }} Location
+ *
  * @typedef {PrettierOptions & {
  *   onDiskFilepath: string;
  *   parserMeta?: ESLint.ObjectMetaProperties['meta'];
@@ -25,6 +27,11 @@
  *   options: Options,
  *   fileInfoOptions: FileInfoOptions,
  * ) => string} PrettierFormat
+ *
+ *
+ * @typedef {Parameters<
+ *   Exclude<ESLint.Plugin['rules'], undefined>[string]['create']
+ * >[0]} RuleContext
  */
 
 'use strict';
@@ -57,10 +64,29 @@ let prettierFormat;
 //  Rule Definition
 // ------------------------------------------------------------------------------
 
+/**
+ * Converts a byte offset to a Location.
+ *
+ * See also `getLocFromIndex` in `@eslint/js`.
+ *
+ * @param {number[]} lineIndexes
+ * @param {number} offset
+ * @returns {Location}
+ */
+function getLocFromOffset(lineIndexes, offset) {
+  let line = 0;
+  while (line + 1 < lineIndexes.length && lineIndexes[line + 1] < offset) {
+    line += 1;
+  }
+
+  const column = offset - lineIndexes[line];
+  return { line: line + 1, column, offset };
+}
+
 /**
  * Reports a difference.
  *
- * @param {Rule.RuleContext} context - The ESLint rule context.
+ * @param {RuleContext} context - The ESLint rule context.
  * @param {Difference} difference - The difference object.
  * @returns {void}
  */
@@ -71,8 +97,39 @@ function reportDifference(context, difference) {
   // `context.getSourceCode()` was deprecated in ESLint v8.40.0 and replaced
   // with the `sourceCode` property.
   // TODO: Only use property when our eslint peerDependency is >=8.40.0.
-  const [start, end] = range.map(index =>
-    (context.sourceCode ?? context.getSourceCode()).getLocFromIndex(index),
+  const sourceCode = context.sourceCode ?? context.getSourceCode();
+
+  const lazy = {
+    /**
+     * Lazily computes the line indices for `sourceCode`.
+     *
+     * @returns {number[]}
+     */
+    get lineIndexes() {
+      // @ts-ignore
+      delete this.lineIndexes;
+
+      if (!('text' in sourceCode)) {
+        throw new Error(
+          'prettier/prettier: non-textual source code is unsupported',
+        );
+      }
+
+      // @ts-ignore
+      this.lineIndexes = [...sourceCode.text.matchAll(/\n/g)].map(
+        match => match.index,
+      );
+      // first line in the file starts at byte offset 0
+      this.lineIndexes.unshift(0);
+      return this.lineIndexes;
+    },
+  };
+
+  const [start, end] = range.map(
+    index =>
+      // @ts-ignore
+      sourceCode.getLocFromIndex?.(index) ??
+      getLocFromOffset(lazy.lineIndexes, index),
   );
 
   context.report({
@@ -90,7 +147,7 @@ function reportDifference(context, difference) {
 //  Module Definition
 // ------------------------------------------------------------------------------
 
-/** @type {ESLint.Plugin} */
+/** @satisfies {ESLint.Plugin} */
 const eslintPluginPrettier = {
   meta: { name, version },
   configs: {
@@ -168,7 +225,7 @@ const eslintPluginPrettier = {
         const source = sourceCode.text;
 
         return {
-          Program(node) {
+          [sourceCode.ast.type](node) {
             if (!prettierFormat) {
               // Prettier is expensive to load, so only load it if needed.
               prettierFormat = /** @type {PrettierFormat} */ (

package.json

@@ -74,6 +74,7 @@
     "@commitlint/config-conventional": "^19.8.0",
     "@eslint-community/eslint-plugin-eslint-comments": "^4.4.1",
     "@eslint/js": "^9.23.0",
+    "@eslint/json": "^0.12.0",
     "@graphql-eslint/eslint-plugin": "^4.3.0",
     "@html-eslint/parser": "^0.41.0",
     "@prettier/plugin-pug": "^3.2.1",

test/invalid/json.txt

@@ -0,0 +1,22 @@
+CODE:
+{
+"a": [
+"b",
+{"c":
+"d"}
+] }
+
+OUTPUT:
+{
+  "a": ["b", { "c": "d" }]
+}
+
+OPTIONS:
+[]
+
+ERRORS:
+[
+  {
+    message: 'Replace `"a":·[⏎"b",⏎{"c":⏎"d"}⏎]·` with `··"a":·["b",·{·"c":·"d"·}]⏎`',
+  },
+]

test/prettier.mjs

@@ -25,6 +25,7 @@ import eslintPluginPug from 'eslint-plugin-pug';
 import vueEslintParser from 'vue-eslint-parser';
 import * as eslintPluginGraphql from '@graphql-eslint/eslint-plugin';
 import eslintMdx from 'eslint-mdx';
+import eslintPluginJson from '@eslint/json';
 
 const rule = eslintPluginPrettier.rules.prettier;
 const RuleTester =
@@ -380,6 +381,31 @@ runFixture('invalid-prettierrc/*', [
   ],
 ]);
 
+const jsonRuleTester = new RuleTester({
+  plugins: {
+    json: eslintPluginJson,
+  },
+  language: 'json/json',
+});
+
+jsonRuleTester.run('@eslint/json', rule, {
+  valid: [
+    {
+      code: '{}\n',
+      filename: 'empty.json',
+    },
+    {
+      code: '{ "foo": 1 }\n',
+      filename: 'simple.json',
+    },
+  ],
+  invalid: [
+    Object.assign(loadInvalidFixture('json'), {
+      filename: 'invalid.json',
+    }),
+  ],
+});
+
 // ------------------------------------------------------------------------------
 //  Helpers
 // ------------------------------------------------------------------------------