feat: use typescript-eslint's EXPERIMENTAL_useProjectService (#1466)

## PR Checklist

- [x] Addresses an existing open issue: fixes #1211
- [x] That issue was marked as [`status: accepting
prs`](https://github.com/JoshuaKGoldberg/create-typescript-app/issues?q=is%3Aopen+is%3Aissue+label%3A%22status%3A+accepting+prs%22)
- [x] Steps in
[CONTRIBUTING.md](https://github.com/JoshuaKGoldberg/create-typescript-app/blob/main/.github/CONTRIBUTING.md)
were taken

## Overview

Unifies `*.js` and `*.ts` linting with the experimental project service
option. Hooray!

In doing so, I found it easier to lint the `script/*.js` files by
switching them to `.ts`.

This also removes the nice `--no-dts` optimization for `pnpm build`.
Linting files like `bin/index.js` now has types, and `lib/*` needs those
`.d.ts `generated.

Author: JoshuaKGoldberg

.eslintrc.cjs

@@ -32,13 +32,20 @@ module.exports = {
 		{
 			extends: [
 				"plugin:jsdoc/recommended-typescript-error",
-				"plugin:@typescript-eslint/strict",
-				"plugin:@typescript-eslint/stylistic",
+				"plugin:@typescript-eslint/strict-type-checked",
+				"plugin:@typescript-eslint/stylistic-type-checked",
 			],
-			files: ["**/*.ts"],
+			files: ["**/*.js", "**/*.ts"],
 			parser: "@typescript-eslint/parser",
+			parserOptions: {
+				EXPERIMENTAL_useProjectService: {
+					allowDefaultProjectForFiles: ["./*.*s"],
+					defaultProject: "./tsconfig.json",
+				},
+			},
 			rules: {
 				// These off-by-default rules work well for this repo and we like them on.
+				"deprecation/deprecation": "error",
 				"jsdoc/informative-docs": "error",
 				"logical-assignment-operators": [
 					"error",
@@ -47,37 +54,6 @@ module.exports = {
 				],
 				"operator-assignment": "error",
 
-				// These on-by-default rules don't work well for this repo and we like them off.
-				"jsdoc/require-jsdoc": "off",
-				"jsdoc/require-param": "off",
-				"jsdoc/require-property": "off",
-				"jsdoc/require-returns": "off",
-			},
-		},
-		{
-			files: "**/*.md/*.ts",
-			rules: {
-				"n/no-missing-import": [
-					"error",
-					{ allowModules: ["create-typescript-app"] },
-				],
-			},
-		},
-		{
-			excludedFiles: ["**/*.md/*.ts"],
-			extends: [
-				"plugin:@typescript-eslint/strict-type-checked",
-				"plugin:@typescript-eslint/stylistic-type-checked",
-			],
-			files: ["**/*.ts"],
-			parser: "@typescript-eslint/parser",
-			parserOptions: {
-				project: "./tsconfig.eslint.json",
-			},
-			rules: {
-				// These off-by-default rules work well for this repo and we like them on.
-				"deprecation/deprecation": "error",
-
 				// These more-strict-by-default rules don't work well for this repo and we like them less strict.
 				"@typescript-eslint/no-unnecessary-condition": [
 					"error",
@@ -93,6 +69,21 @@ module.exports = {
 					"error",
 					{ allowBoolean: true, allowNullish: true, allowNumber: true },
 				],
+
+				// These on-by-default rules don't work well for this repo and we like them off.
+				"jsdoc/require-jsdoc": "off",
+				"jsdoc/require-param": "off",
+				"jsdoc/require-property": "off",
+				"jsdoc/require-returns": "off",
+			},
+		},
+		{
+			files: "**/*.md/*.ts",
+			rules: {
+				"n/no-missing-import": [
+					"error",
+					{ allowModules: ["create-typescript-app"] },
+				],
 			},
 		},
 		{

.github/DEVELOPMENT.md

@@ -146,7 +146,7 @@ Note that the files need to be built with `pnpm run build` beforehand.
 pnpm run test:create
 ```
 
-That end-to-end test executes `script/create-test-e2e.js`, which:
+That end-to-end test executes `script/create-test-e2e.ts`, which:
 
 1. Runs the creation script to create a new `test-repository` child directory and repository, capturing code coverage
 2. Asserts that commands such as `build` and `lint` each pass
@@ -175,7 +175,7 @@ Note that files need to be built with `pnpm run build` beforehand.
 pnpm run test:initialize
 ```
 
-That end-to-end test executes `script/initialize-test-e2e.js`, which:
+That end-to-end test executes `script/initialize-test-e2e.ts`, which:
 
 1. Runs the initialization script using `--skip-github-api` and other skip flags
 2. Checks that the local repository's files were changed correctly (e.g. removed initialization-only files)
@@ -221,7 +221,7 @@ You can run the end-to-end test for migrating locally on the command-line:
 pnpm run test:migrate
 ```
 
-That end-to-end test executes `script/migrate-test-e2e.js`, which:
+That end-to-end test executes `script/migrate-test-e2e.ts`, which:
 
 1. Runs the migration script using `--skip-github-api` and other skip flags, capturing code coverage
 2. Checks that only a small list of allowed files were changed
@@ -234,7 +234,7 @@ See `.github/workflows/test-migrate.yml`.
 
 ##### Migration Snapshot Failures
 
-The migration test uses the [Vitest file snapshot](https://vitest.dev/guide/snapshot#file-snapshots) in `script/__snapshots__/migrate-test-e2e.js.snap` to store expected differences to this repository after running the migration script.
+The migration test uses the [Vitest file snapshot](https://vitest.dev/guide/snapshot#file-snapshots) in `script/__snapshots__/migrate-test-e2e.ts.snap` to store expected differences to this repository after running the migration script.
 The end-to-end migration test will fail any changes that don't keep the same differences in that snapshot.
 
 You can update the snapshot file by:
@@ -245,7 +245,7 @@ You can update the snapshot file by:
 
 At this point there will be some files changed:
 
-- `script/__snapshots__/migrate-test-e2e.js.snap` will have updates if any files mismatched templates
+- `script/__snapshots__/migrate-test-e2e.ts.snap` will have updates if any files mismatched templates
 - The actual updated files on disk will be there too
 
 If the snapshot file changes are what you expected, then you can commit them.

.github/workflows/lint.yml

@@ -4,7 +4,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: ./.github/actions/prepare
-      - run: pnpm build --no-dts
+      - run: pnpm build
       - run: pnpm lint
 
 name: Lint

package.json

@@ -29,8 +29,8 @@
 		"lint:spelling": "cspell \"**\" \".github/**/*\"",
 		"prepare": "husky",
 		"test": "vitest",
-		"test:create": "node script/create-test-e2e.js",
-		"test:initialize": "node script/initialize-test-e2e.js",
+		"test:create": "npx tsx script/create-test-e2e.ts",
+		"test:initialize": "npx tsx script/initialize-test-e2e.ts",
 		"test:migrate": "vitest run -r script/",
 		"tsc": "tsc"
 	},

script/__snapshots__/migrate-test-e2e.js.snap script/__snapshots__/migrate-test-e2e.ts.snap

@@ -27,10 +27,9 @@ exports[`expected file changes > .eslintrc.cjs 1`] = `
  		{
  			extends: ["plugin:markdown/recommended-legacy"],
 @@ ... @@ module.exports = {
- 			rules: {
- 				// These off-by-default rules work well for this repo and we like them on.
- 				"deprecation/deprecation": "error",
--
+ 				],
+ 				"operator-assignment": "error",
+ 
 -				// These more-strict-by-default rules don't work well for this repo and we like them less strict.
 -				"@typescript-eslint/no-unnecessary-condition": [
 -					"error",
@@ -46,9 +45,10 @@ exports[`expected file changes > .eslintrc.cjs 1`] = `
 -					"error",
 -					{ allowBoolean: true, allowNullish: true, allowNumber: true },
 -				],
- 			},
- 		},
- 		{"
+-
+ 				// These on-by-default rules don't work well for this repo and we like them off.
+ 				"jsdoc/require-jsdoc": "off",
+ 				"jsdoc/require-param": "off","
 `;
 
 exports[`expected file changes > .github/workflows/test.yml 1`] = `
@@ -129,6 +129,7 @@ exports[`expected file changes > cspell.json 1`] = `
  		"execa",
  		"infile",
 +		"joshuakgoldberg",
++		"jsdoc",
  		"knip",
 +		"markdownlint",
  		"markdownlintignore",

script/create-test-e2e.js script/create-test-e2e.ts

@@ -19,7 +19,7 @@ await $({
 
 const newPackageJson = JSON.parse(
 	(await fs.readFile("./package.json")).toString(),
-);
+) as Record<string, string>;
 console.log("New package JSON:", newPackageJson);
 
 assert.equal(newPackageJson.description, description);
@@ -45,7 +45,9 @@ for (const search of [`/JoshuaKGoldberg/`, "create-typescript-app"]) {
 try {
 	await $`pnpm run lint:knip`;
 } catch (error) {
-	throw new Error("Error running lint:knip:", { cause: error });
+	throw new Error(
+		`Error running lint:knip: ${(error as Error).stack ?? (error as string)}`,
+	);
 }
 
 // Now that initialize has passed normal steps, we reset everything,

script/initialize-test-e2e.js script/initialize-test-e2e.ts

@@ -18,7 +18,7 @@ const filesExpectedToBeChanged = [
 
 const filesThatMightBeChanged = new Set([
 	...filesExpectedToBeChanged,
-	"script/__snapshots__/migrate-test-e2e.js.snap",
+	"script/__snapshots__/migrate-test-e2e.ts.snap",
 ]);
 
 const {
@@ -41,7 +41,7 @@ await rimraf("coverage*");
 const originalReadme = (await fs.readFile("README.md")).toString();
 
 const originalSnapshots = (
-	await fs.readFile("script/__snapshots__/migrate-test-e2e.js.snap")
+	await fs.readFile("script/__snapshots__/migrate-test-e2e.ts.snap")
 ).toString();
 
 await $({
@@ -71,27 +71,31 @@ await fs.writeFile(
 		updatedReadme.slice(updatedReadme.indexOf("<!-- markdownlint-restore -->")),
 	]
 		.join("")
-		.replaceAll(
+		.replace(
 			/All Contributors: \d+/g,
-			originalReadme.match(/All Contributors: \d+/)[0],
+			// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+			originalReadme.match(/All Contributors: \d+/)![0],
 		)
-		.replaceAll(
+		.replace(
 			/all_contributors-\d+/g,
-			originalReadme.match(/all_contributors-\d+/)[0],
+			// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+			originalReadme.match(/all_contributors-\d+/)![0],
 		),
 );
 
 // ...and even to the snapshot file, so diffs don't mind it.
 await fs.writeFile(
-	"script/__snapshots__/migrate-test-e2e.js.snap",
+	"script/__snapshots__/migrate-test-e2e.ts.snap",
 	originalSnapshots
-		.replaceAll(
+		.replace(
 			/All Contributors: \d+/g,
-			originalReadme.match(/All Contributors: \d+/)[0],
+			// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+			originalReadme.match(/All Contributors: \d+/)![0],
 		)
-		.replaceAll(
+		.replace(
 			/all_contributors-\d+/g,
-			originalReadme.match(/all_contributors-\d+/)[0],
+			// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+			originalReadme.match(/all_contributors-\d+/)![0],
 		),
 );
 
@@ -102,7 +106,7 @@ describe("expected file changes", () => {
 			.split("\n")
 			.slice(2)
 			.join("\n")
-			.replaceAll(/@@ -\d+,\d+ \+\d+,\d+ @@/g, "@@ ... @@");
+			.replace(/@@ -\d+,\d+ \+\d+,\d+ @@/g, "@@ ... @@");
 
 		assert(
 			stdout,
@@ -130,13 +134,13 @@ test("unexpected file changes", async () => {
 
 	const unstagedModifiedFiles = gitStatus
 		.slice(indexOfUnstagedFilesMessage)
-		.match(/modified: {3}(\S+)\n/g)
-		.map((match) => match.split(/\s+/g)[1])
+		.match(/modified: {3}\S+\n/g)
+		?.map((match) => match.split(/\s+/)[1])
 		.filter((filePath) => !filesThatMightBeChanged.has(filePath));
 
 	console.log("Unexpected modified files are:", unstagedModifiedFiles);
 
-	if (unstagedModifiedFiles.length) {
+	if (unstagedModifiedFiles?.length) {
 		const gitDiffCommand = `git diff HEAD -- ${unstagedModifiedFiles.join(
 			" ",
 		)}`;

script/migrate-test-e2e.js script/migrate-test-e2e.ts

@@ -1,3 +1,3 @@
 import { defineConfig } from "vitest/config";
 
-export default defineConfig({ test: { include: ["./migrate-test-e2e.js"] } });
+export default defineConfig({ test: { include: ["./migrate-test-e2e.ts"] } });

script/vitest.config.ts

@@ -20,7 +20,7 @@ describe("createCleanupCommands", () => {
 
 		expect(actual).toEqual([
 			"pnpm dedupe",
-			"pnpm build --no-dts",
+			"pnpm build",
 			"pnpm lint --fix",
 			"pnpm format --write",
 		]);

src/shared/createCleanupCommands.test.ts

@@ -8,7 +8,7 @@ export function createCleanupCommands({
 		// There's no need to dedupe when initializing from the fixed template
 		...(mode === "initialize" ? [] : ["pnpm dedupe"]),
 		// n/no-missing-import rightfully reports on a missing the bin .js file
-		...(bin ? ["pnpm build --no-dts"] : []),
+		...(bin ? ["pnpm build"] : []),
 		"pnpm lint --fix",
 		"pnpm format --write",
 	];

src/shared/createCleanupCommands.ts

@@ -61,11 +61,18 @@ describe("createESLintRC", () => {
 				  ignorePatterns: ["!.*", "lib", "node_modules", "pnpm-lock.yaml"],
 				  overrides: [
 				    {
-				      extends: ["plugin:@typescript-eslint/recommended"],
-				      files: ["**/*.ts"],
+				      extends: ["plugin:@typescript-eslint/recommended-type-checked"],
+				      files: ["**/*.js", "**/*.ts"],
 				      parser: "@typescript-eslint/parser",
+				      parserOptions: {
+				        EXPERIMENTAL_useProjectService: {
+				          allowDefaultProjectForFiles: ["./*.*s"],
+				          defaultProject: "./tsconfig.json",
+				        },
+				      },
 				      rules: {
 				        // These off-by-default rules work well for this repo and we like them on.
+				        "deprecation/deprecation": "error",
 				        "logical-assignment-operators": [
 				          "error",
 				          "always",
@@ -80,14 +87,6 @@ describe("createESLintRC", () => {
 				        "n/no-missing-import": ["error", { allowModules: ["test-repository"] }],
 				      },
 				    },
-				    {
-				      extends: ["plugin:@typescript-eslint/recommended-type-checked"],
-				      files: ["**/*.ts"],
-				      parser: "@typescript-eslint/parser",
-				      parserOptions: {
-				        project: "./tsconfig.eslint.json",
-				      },
-				    },
 				  ],
 				  parser: "@typescript-eslint/parser",
 				  plugins: ["@typescript-eslint"],
@@ -135,13 +134,20 @@ describe("createESLintRC", () => {
 				    {
 				      extends: [
 				        "plugin:jsdoc/recommended-typescript-error",
-				        "plugin:@typescript-eslint/strict",
-				        "plugin:@typescript-eslint/stylistic",
+				        "plugin:@typescript-eslint/strict-type-checked",
+				        "plugin:@typescript-eslint/stylistic-type-checked",
 				      ],
-				      files: ["**/*.ts"],
+				      files: ["**/*.js", "**/*.ts"],
 				      parser: "@typescript-eslint/parser",
+				      parserOptions: {
+				        EXPERIMENTAL_useProjectService: {
+				          allowDefaultProjectForFiles: ["./*.*s"],
+				          defaultProject: "./tsconfig.json",
+				        },
+				      },
 				      rules: {
 				        // These off-by-default rules work well for this repo and we like them on.
+				        "deprecation/deprecation": "error",
 				        "jsdoc/informative-docs": "error",
 				        "logical-assignment-operators": [
 				          "error",
@@ -163,22 +169,6 @@ describe("createESLintRC", () => {
 				        "n/no-missing-import": ["error", { allowModules: ["test-repository"] }],
 				      },
 				    },
-				    {
-				      excludedFiles: ["**/*.md/*.ts"],
-				      extends: [
-				        "plugin:@typescript-eslint/strict-type-checked",
-				        "plugin:@typescript-eslint/stylistic-type-checked",
-				      ],
-				      files: ["**/*.ts"],
-				      parser: "@typescript-eslint/parser",
-				      parserOptions: {
-				        project: "./tsconfig.eslint.json",
-				      },
-				      rules: {
-				        // These off-by-default rules work well for this repo and we like them on.
-				        "deprecation/deprecation": "error",
-				      },
-				    },
 				    {
 				      excludedFiles: ["package.json"],
 				      extends: ["plugin:jsonc/recommended-with-json"],