Increase JS budgets

Add failsafe for empty browserlist. Add comment to describe prefix issue in literals. Use default browserlistEnv naming convention. SW uses more efficient browserlist only targeting browsers that support sw.

build-scripts/bundle-budget.json

@@ -1,15 +1,15 @@
 {
   "_comment": "Initial JS budget (raw/uncompressed bytes) for the cold-load critical entrypoints. Enforced by build-scripts/check-bundle-size.cjs in CI. Re-seed after an intentional change with `--update --headroom=<percent>`.",
   "frontend-modern": {
-    "app": 561513,
-    "core": 54473,
-    "authorize": 544272,
-    "onboarding": 647136
+    "app": 595204,
+    "core": 57741,
+    "authorize": 576928,
+    "onboarding": 685964
   },
   "frontend-legacy": {
-    "app": 790323,
-    "core": 237208,
-    "authorize": 765464,
-    "onboarding": 918679
+    "app": 861452,
+    "core": 258557,
+    "authorize": 834356,
+    "onboarding": 1001360
   }
 }

build-scripts/minify-template-literals-loader.cjs

@@ -12,18 +12,42 @@
 const remapping = require("@ampproject/remapping");
 
 // minify-literals is ESM-only, so load it via dynamic import from this CJS loader.
-let minifyPromise;
-const getMinifier = () => {
-  if (!minifyPromise) {
-    minifyPromise = import("minify-literals").then((m) => m.minifyHTMLLiterals);
+// Also map to cache loader promises per environment (e.g., 'modern', 'legacy')
+const loaderInitPromises = new Map();
+const initLoader = (browserslistEnv) => {
+  if (!loaderInitPromises.has(browserslistEnv)) {
+    loaderInitPromises.set(
+      browserslistEnv,
+      Promise.all([
+        import("minify-literals"),
+        import("browserslist"),
+        import("lightningcss"),
+      ]).then(([minifyModule, browserslistModule, lightningcssModule]) => {
+        const browserslist = browserslistModule.default;
+        const { browserslistToTargets } = lightningcssModule;
+        const rawTargets = browserslist(null, { env: browserslistEnv });
+        if (!rawTargets.length) {
+          throw new Error(
+            `No browsers resolved for browserslist environment "${browserslistEnv}"`
+          );
+        }
+        const lightningcssTargets = browserslistToTargets(rawTargets);
+
+        return {
+          minifyHTMLLiterals: minifyModule.minifyHTMLLiterals,
+          lightningcssTargets,
+        };
+      })
+    );
   }
-  return minifyPromise;
+  return loaderInitPromises.get(browserslistEnv);
 };
 
 // HTML options mirror the previous babel-plugin-template-html-minifier config
 // (html-minifier-next is option-compatible with html-minifier-terser). CSS in
-// css`` templates and inline <style> is handled by minify-literals' lightningcss
-// default.
+// css`` templates and inline <style> is handled by minify-literals'
+// lightningcss. We pass in the targets from browserslist so lightningcss
+// can minify CSS appropriately for the build environment.
 //
 // `keepClosingSlash` is required for `svg`` templates: SVG elements such as
 // `<path />` and `<circle />` are not void elements in HTML, so dropping the
@@ -40,11 +64,16 @@ const htmlOptions = {
 
 module.exports = function minifyTemplateLiteralsLoader(source, map, meta) {
   const callback = this.async();
-  getMinifier()
-    .then((minifyHTMLLiterals) =>
+  const { browserslistEnv } = this.getOptions();
+
+  initLoader(browserslistEnv)
+    .then(({ minifyHTMLLiterals, lightningcssTargets }) =>
       minifyHTMLLiterals(source, {
         fileName: this.resourcePath,
         html: htmlOptions,
+        css: {
+          targets: lightningcssTargets,
+        },
       })
     )
     .then((result) => {

build-scripts/rspack.cjs

@@ -96,6 +96,11 @@ const createRspackConfig = ({
                   __dirname,
                   "minify-template-literals-loader.cjs"
                 ),
+                options: {
+                  browserslistEnv: latestBuild
+                    ? "modern"
+                    : `legacy${info.issuerLayer === "sw" ? "-sw" : ""}`,
+                },
               },
               !latestBuild &&
                 info.resource.startsWith(

src/components/ha-snowflakes.ts

@@ -1,6 +1,7 @@
 import type { PropertyValues } from "lit";
 import { css, html, LitElement, nothing } from "lit";
 import { customElement, property, state } from "lit/decorators";
+import { styleMap } from "lit/directives/style-map";
 import type { HomeAssistant } from "../types";
 import { subscribeLabFeature } from "../data/labs";
 import { SubscribeMixin } from "../mixins/subscribe-mixin";
@@ -81,14 +82,14 @@ export class HaSnowflakes extends SubscribeMixin(LitElement) {
               class="snowflake ${
                 this.narrow && flake.id >= 30 ? "hide-narrow" : ""
               }"
-              style="
-                left: ${flake.left}%;
-                width: ${flake.size}px;
-                height: ${flake.size}px;
-                animation-duration: ${flake.duration}s;
-                animation-delay: ${flake.delay}s;
-                --rotation: ${flake.rotation}deg;
-              "
+              style=${styleMap({
+                left: `${flake.left}%`,
+                width: `${flake.size}px`,
+                height: `${flake.size}px`,
+                "animation-duration": `${flake.duration}s`,
+                "animation-delay": `${flake.delay}s`,
+                "--rotation": `${flake.rotation}deg`,
+              })}
               viewBox="0 0 16 16"
               fill="none"
               xmlns="http://www.w3.org/2000/svg"