refactor: migrate to esm, use pkg-utils for build, switch tests to Vitest

Author: rdunk

build/compat-runtime-stubs.mjs

@@ -0,0 +1,44 @@
+// Generates backwards compatible runtime no-ops after build completes
+// - lib/empty.js   → empty ESM module (runtime no-op)
+// - lib/empty.cjs  → empty CJS module (runtime no-op)
+
+import {mkdirSync, writeFileSync} from 'node:fs'
+import {fileURLToPath} from 'node:url'
+import path from 'node:path'
+
+// Logging helpers
+const GREY = '\x1b[0m'
+const GREEN = '\x1b[32m'
+const RED = '\x1b[31m'
+const TAG = `[compat-shims]${GREY}`
+const info = (msg) => console.log(`${GREEN}${TAG} ${msg}`)
+const fail = (msg, err) => {
+  console.error(`${RED}${TAG}${GREY} ${msg}`)
+  if (err) console.error(err)
+  process.exitCode = 1
+}
+
+const __filename = fileURLToPath(import.meta.url)
+const __dirname = path.dirname(__filename)
+const LIB_DIR = path.resolve(__dirname, '..', 'lib', 'compat')
+const EMPTY_ESM = path.join(LIB_DIR, 'empty.js')
+const EMPTY_CJS = path.join(LIB_DIR, 'empty.cjs')
+const compatComment = '// Generated for backwards compatibility'
+
+try {
+  mkdirSync(LIB_DIR, {recursive: true})
+
+  const esmStub = `${compatComment}
+export {}
+`
+  const cjsStub = `${compatComment}
+module.exports = {}
+`
+
+  writeFileSync(EMPTY_ESM, esmStub, 'utf8')
+  writeFileSync(EMPTY_CJS, cjsStub, 'utf8')
+
+  info('Wrote runtime compat no-op files')
+} catch (err) {
+  fail('Failed to write runtime compat no-op files', err)
+}

index.js

@@ -0,0 +1,10 @@
+import {defineConfig} from '@sanity/pkg-utils'
+
+export default defineConfig({
+  extract: {
+    rules: {
+      'ae-internal-missing-underscore': 'off',
+    },
+  },
+  tsconfig: 'tsconfig.json',
+})

package.config.ts

@@ -2,55 +2,50 @@
   "name": "@sanity/image-url",
   "version": "1.2.0",
   "description": "Tools to generate image urls from Sanity content",
-  "source": "src/builder.ts",
-  "main": "lib/node/index.js",
-  "browser": "lib/browser/image-url.umd.js",
-  "umd:main": "lib/browser/image-url.umd.js",
-  "typings": "lib/types/index.d.ts",
+  "type": "module",
+  "exports": {
+    ".": {
+      "source": "./src/index.ts",
+      "import": "./lib/index.js",
+      "require": "./lib/index.cjs",
+      "default": "./lib/index.js"
+    },
+    "./lib/types/*": {
+      "import": "./lib/compat/empty.js",
+      "require": "./lib/compat/empty.cjs",
+      "default": "./lib/compat/empty.js"
+    },
+    "./package.json": "./package.json"
+  },
+  "main": "./lib/index.cjs",
+  "module": "./lib/index.js",
+  "types": "./lib/index.d.ts",
   "files": [
     "lib",
-    "index.js",
-    "urlForImage.js"
+    "src",
+    "build/compat-shims.mjs"
   ],
   "sideEffects": false,
   "amdName": "SanityImageUrlBuilder",
   "scripts": {
     "prepublishOnly": "npm run build",
     "prebuild": "rimraf lib coverage .rts2*",
-    "build": "npm run build:node && npm run build:browser",
-    "build:node": "tsc -m commonjs",
-    "build:browser": "microbundle build -i src/browser.ts -o lib/browser -f umd,es --no-compress",
+    "build": "pkg build --strict",
+    "build:compat": "tsc -p tsconfig.compat.json && node build/compat-runtime-stubs.mjs",
+    "postbuild": "npm run build:compat",
+    "prepack": "npm run build:compat",
     "lint": "tslint  --project tsconfig.json -t codeFrame 'src/**/*.ts' 'test/**/*.ts'",
-    "test": "jest --coverage",
-    "test:watch": "jest --coverage --watch",
+    "test": "vitest run --coverage",
+    "test:watch": "vitest coverage",
     "test:prod": "npm run lint && npm run test -- --no-cache",
     "posttest": "npm run lint",
     "format": "prettier . --write",
     "release": "changeset publish"
   },
+  "browserslist": "extends @sanity/browserslist-config",
   "engines": {
     "node": ">=10.0.0"
   },
-  "jest": {
-    "transform": {
-      ".(ts|tsx)": "ts-jest"
-    },
-    "testEnvironment": "node",
-    "testURL": "http://localhost",
-    "testRegex": "(/__tests__/.*|\\.(test|spec))\\.(ts|tsx|js)$",
-    "moduleFileExtensions": [
-      "ts",
-      "tsx",
-      "js"
-    ],
-    "coveragePathIgnorePatterns": [
-      "/node_modules/",
-      "/test/"
-    ],
-    "collectCoverageFrom": [
-      "src/*.{js,ts}"
-    ]
-  },
   "prettier": {
     "semi": false,
     "singleQuote": true,
@@ -66,16 +61,16 @@
     "@changesets/changelog-github": "^0.5.1",
     "@changesets/cli": "^2.29.6",
     "@sanity/client": "^6.22.2",
-    "@types/jest": "^27.4.0",
-    "@types/node": "^17.0.18",
-    "jest": "^27.5.1",
+    "@sanity/pkg-utils": "^8.0.3",
+    "@types/node": "^24.3.0",
+    "@vitest/coverage-v8": "^3.2.4",
     "microbundle": "^0.15.1",
     "prettier": "^2.5.1",
     "rimraf": "^3.0.2",
-    "ts-jest": "^27.1.3",
     "tslint": "^6.1.3",
     "tslint-config-prettier": "^1.15.0",
-    "typescript": "^4.5.5"
+    "typescript": "^5.9.2",
+    "vitest": "^3.2.4"
   },
   "repository": {
     "type": "git",