ci: only format and lint changed files

.eslintignore

@@ -0,0 +1,3 @@
+scripts/*
+.eslintignore
+.prettierignore

.eslintrc.cjs

@@ -11,7 +11,7 @@ module.exports = {
     'plugin:svelte/recommended',
     'prettier',
   ],
-  plugins: ['svelte', 'simple-import-sort'],
+  plugins: ['svelte', 'simple-import-sort', 'json-files'],
   rules: {
     'simple-import-sort/imports': 'error',
   },

.prettierignore

@@ -0,0 +1,3 @@
+scripts/*
+.eslintignore
+.prettierignore

package.json

@@ -44,13 +44,19 @@
   ],
   "scripts": {
     "toc": "doctoc README.md",
-    "lint": "(prettier . --check || true) && eslint .",
+    "lint": "prettier . --check && eslint .",
+    "lint:delta": "npm-run-all -p prettier:delta eslint:delta",
+    "prettier:delta": "prettier --check `./scripts/changed-files`",
+    "eslint:delta": "eslint `./scripts/changed-files`",
     "format": "prettier . --write && eslint . --fix",
+    "format:delta": "npm-run-all format:prettier:delta format:eslint:delta",
+    "format:prettier:delta": "prettier --write `./scripts/changed-files`",
+    "format:eslint:delta": "eslint --fix `./scripts/changed-files`",
     "test": "vitest run --coverage",
     "test:watch": "vitest",
     "test:update": "vitest run --update",
     "setup": "npm install && npm run validate",
-    "validate": "npm-run-all lint test",
+    "validate": "npm-run-all lint:delta test",
     "contributors:add": "all-contributors add",
     "contributors:generate": "all-contributors generate"
   },
@@ -74,6 +80,7 @@
     "eslint-config-prettier": "^9.1.0",
     "eslint-config-standard": "^17.1.0",
     "eslint-plugin-import": "^2.27.5",
+    "eslint-plugin-json-files": "^4.1.0",
     "eslint-plugin-n": "^16.0.1",
     "eslint-plugin-promise": "^6.1.1",
     "eslint-plugin-simple-import-sort": "^10.0.0",

scripts/changed-files

@@ -0,0 +1,3 @@
+#!/usr/bin/env bash
+
+git diff --name-only --diff-filter=d main