Update dependency: eslint to 9.1.1, update to ESLint 9's "flat" confi…

…guration file format.

.vscodeignore

@@ -9,6 +9,7 @@ webworker
 .npmrc
 .vscodeignore
 CONTRIBUTING.md
+eslint.config.mjs
 extension.js
 generate-config-schema.js
 jsconfig.json

eslint.config.mjs

@@ -0,0 +1,70 @@
+/* eslint-disable n/no-unpublished-import */
+
+import js from "@eslint/js";
+import eslintPluginN from "eslint-plugin-n";
+import eslintPluginUnicorn from "eslint-plugin-unicorn";
+
+export default [
+	js.configs.all,
+	eslintPluginN.configs["flat/recommended"],
+	eslintPluginUnicorn.configs["flat/all"],
+	{
+		"languageOptions": {
+			"sourceType": "commonjs",
+		},
+		"linterOptions": {
+			"reportUnusedDisableDirectives": true
+		},
+		"rules": {
+			"array-bracket-spacing": [ "error", "always" ],
+			"dot-location": [ "error", "property" ],
+			"func-style": [ "error", "declaration" ],
+			"function-call-argument-newline": [ "error", "consistent" ],
+			"function-paren-newline": [ "error", "consistent" ],
+			"global-require": "off",
+			"indent": [ "error", "tab" ],
+			"linebreak-style": "off",
+			"max-classes-per-file": "off",
+			"max-depth": [ "error", 6 ],
+			"max-len": [ "error", 130 ],
+			"max-lines": "off",
+			"max-lines-per-function": "off",
+			"max-statements": "off",
+			"multiline-comment-style": [ "error", "separate-lines" ],
+			"no-extra-parens": "off",
+			"no-magic-numbers": "off",
+			"no-plusplus": "off",
+			"no-promise-executor-return": "off",
+			"no-sync": "off",
+			"no-tabs": "off",
+			"no-ternary": "off",
+			"no-undefined": "off",
+			"no-use-before-define": [ "error", { "functions": false } ],
+			"one-var": "off",
+			"operator-linebreak": [ "error", "after" ],
+			"padded-blocks": "off",
+			"prefer-destructuring": "off",
+			"prefer-named-capture-group": "off",
+			"prefer-template": "off",
+			"require-unicode-regexp": "off",
+			"sort-imports": "off",
+			"sort-keys": "off",
+
+			"n/no-missing-require": [ "error", { "allowModules": [ "vscode" ] } ],
+
+			"unicorn/no-array-push-push": "off",
+			"unicorn/no-array-reduce": "off",
+			"unicorn/no-null": "off",
+			"unicorn/prefer-module": "off",
+			"unicorn/prefer-string-replace-all": "off"
+		}
+	},
+	{
+		"files": [
+			"**/*.mjs"
+		],
+		"languageOptions": {
+			"sourceType": "module"
+		}
+	}
+];

package.json

@@ -23,7 +23,7 @@
 		"ci": "npm test && npm run test-ui",
 		"compile": "webpack --mode production",
 		"compile-debug": "webpack --mode none",
-		"lint": "eslint --ignore-pattern bundle.js --ignore-pattern bundle.web.js *.js *.cjs test-ui/*.cjs && markdownlint-cli2 *.md",
+		"lint": "eslint --ignore-pattern bundle.js --ignore-pattern bundle.web.js *.js *.cjs test-ui/*.cjs eslint.config.mjs --max-warnings 0 && markdownlint-cli2 *.md",
 		"schema": "cpy ./node_modules/markdownlint/schema/markdownlint-config-schema.json . --flat && cpy ./node_modules/markdownlint-cli2/schema/markdownlint-cli2-config-schema.json . --flat",
 		"test": "node --test --experimental-test-coverage && npm run lint && npm run compile && npm run schema && git diff --exit-code",
 		"test-ui": "node ./test-ui/run-tests.mjs",
@@ -46,10 +46,11 @@
 		"picomatch": "4.0.2"
 	},
 	"devDependencies": {
+		"@eslint/js": "9.1.1",
 		"@types/vscode": "1.75.0",
 		"@vscode/test-electron": "2.3.9",
 		"cpy-cli": "5.0.0",
-		"eslint": "8.56.0",
+		"eslint": "9.1.1",
 		"eslint-plugin-n": "17.2.1",
 		"eslint-plugin-unicorn": "52.0.0",
 		"path-browserify": "1.0.1",