Set target es2024 in TS and Vite, drop browserslist

app/api/__tests__/safety.spec.ts

@@ -11,6 +11,8 @@ import path from 'path'
 
 import { expect, it } from 'vitest'
 
+import viteConfigFn from '../../../vite.config'
+
 it('Generated API client version matches API version specified for deployment', () => {
   const generatedVersion = fs
     .readFileSync(path.resolve(__dirname, '../__generated__/OMICRON_VERSION'), 'utf8')
@@ -40,6 +42,20 @@ it('API_VERSION file matches apiVersion in generated client', () => {
   expect(match?.[1]).toEqual(apiVersionFile)
 })
 
+// tsc is the only thing preventing use of JS APIs missing from our supported
+// browsers: Vite's build neither polyfills nor warns about calls to unsupported
+// APIs, it only transpiles syntax. So we want to make sure vite and tsc have
+// the same target.
+it('vite build target matches tsconfig target', () => {
+  const tsconfig = JSON.parse(
+    fs.readFileSync(path.resolve(__dirname, '../../../tsconfig.json'), 'utf8')
+  )
+  const viteConfig = viteConfigFn({ mode: 'production', command: 'build' })
+  // guard against an undefined === undefined pass if both are removed
+  expect(tsconfig.compilerOptions.target).toMatch(/^es\d{4}$/)
+  expect(viteConfig.build?.target).toEqual(tsconfig.compilerOptions.target)
+})
+
 const grepFiles = (s: string) =>
   execSync(`git grep -l "${s}"`)
     .toString()

package.json

@@ -95,7 +95,6 @@
     "@vitejs/plugin-basic-ssl": "^2.3.0",
     "@vitejs/plugin-react": "^6.0.2",
     "@vitest/browser-playwright": "^4.1.11",
-    "autoprefixer": "^10.4.20",
     "eslint-plugin-playwright": "^2.10.4",
     "eslint-plugin-react-hook-form": "^0.3.1",
     "husky": "^9.1.7",
@@ -113,9 +112,6 @@
     "vitest": "^4.1.11",
     "vitest-browser-react": "^2.2.0"
   },
-  "browserslist": [
-    "defaults"
-  ],
   "msw": {
     "workerDirectory": [
       ""

tsconfig.json

@@ -15,7 +15,7 @@
       "@oxide/api-mocks": ["./mock-api/index.ts"]
     },
     "skipLibCheck": true,
-    "target": "es2023",
+    "target": "es2024",
     "types": ["node", "vite/client", "vitest/importMeta"]
   },
   "exclude": ["tools/deno"]

vite.config.ts

@@ -96,6 +96,12 @@ const devHeaders = {
 // see https://vitejs.dev/config/
 export default defineConfig(({ mode }) => ({
   build: {
+    // Must match `target` in tsconfig.json: tsc only checks against lib types
+    // and nothing polyfills missing APIs, so the browser floor and the type
+    // ceiling have to move together. Vite maps this to the oldest browsers
+    // with full ES2024 support. We pin it because the default
+    // (baseline-widely-available) drifts across Vite versions.
+    target: 'es2024',
     outDir: resolve(__dirname, 'dist'),
     emptyOutDir: true,
     sourcemap: true,