diff --git a/packages/producer/src/services/deterministicFonts-textSubset.test.ts b/packages/producer/src/services/deterministicFonts-textSubset.test.ts
new file mode 100644
index 0000000000..0bcb8931ef
--- /dev/null
+++ b/packages/producer/src/services/deterministicFonts-textSubset.test.ts
@@ -0,0 +1,25 @@
+import { describe, expect, it } from "bun:test";
+import { injectDeterministicFontFaces } from "./deterministicFonts.js";
+
+describe("Google Fonts text subsetting", () => {
+ it("sends the composition character set to the CSS API", async () => {
+ let requestedUrl = "";
+ const fetchImpl = (async (input: unknown) => {
+ requestedUrl = String(input);
+ return new Response("", { status: 400 });
+ }) as unknown as typeof fetch;
+
+ await injectDeterministicFontFaces(
+ `旅行ランキング
`,
+ { fetchImpl, allowSystemFontCapture: false },
+ );
+
+ const url = new URL(requestedUrl);
+ const text = url.searchParams.get("text") ?? "";
+ for (const character of new Set("旅行ランキング")) {
+ expect(text).toContain(character);
+ }
+ });
+});
diff --git a/packages/producer/src/services/deterministicFonts.ts b/packages/producer/src/services/deterministicFonts.ts
index 2805bae2e9..6bebd8e213 100644
--- a/packages/producer/src/services/deterministicFonts.ts
+++ b/packages/producer/src/services/deterministicFonts.ts
@@ -456,6 +456,7 @@ function buildFontFaceRule(
async function buildFontFaceCss(
requestedFamilies: Map,
options: InternalFontFetchOptions,
+ fontText?: string,
): Promise<{
css: string;
unresolved: string[];
@@ -483,7 +484,7 @@ async function buildFontFaceCss(
// already covered by the embedded bundle. This ensures that
// compositions requesting e.g. wght@200 get that weight even
// if the bundle only ships 400/700/900.
- const googleFaces = await fetchGoogleFont(originalCaseFamily, options);
+ const googleFaces = await fetchGoogleFont(originalCaseFamily, options, fontText);
for (const face of googleFaces) {
// A weight covered by the embedded bundle is already full-coverage —
// skip it. For weights the bundle lacks, add EVERY subset face (a
@@ -503,7 +504,7 @@ async function buildFontFaceCss(
}
// Path 2: fetch from Google Fonts (with local cache)
- const googleFaces = await fetchGoogleFont(originalCaseFamily, options);
+ const googleFaces = await fetchGoogleFont(originalCaseFamily, options, fontText);
if (googleFaces.length > 0) {
for (const face of googleFaces) {
rules.push(
@@ -735,10 +736,12 @@ async function ensureWoff2DataUri(
async function fetchGoogleFont(
familyName: string,
options: InternalFontFetchOptions,
+ fontText?: string,
): Promise {
const slug = fontSlug(familyName);
const encodedFamily = encodeURIComponent(familyName);
- const url = `https://fonts.googleapis.com/css2?family=${encodedFamily}:ital,wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,400;1,700`;
+ const textParam = fontText ? `&text=${encodeURIComponent(fontText)}` : "";
+ const url = `https://fonts.googleapis.com/css2?family=${encodedFamily}:ital,wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,400;1,700${textParam}`;
let cssText: string;
try {
@@ -844,6 +847,18 @@ export interface InjectDeterministicFontFacesOptions {
allowSystemFontCapture?: boolean;
}
+// Keep the complete CSS request under the broadly supported ~2 KB URL limit.
+// Using unique source characters covers static text plus strings authored in
+// scripts, while collapsing repeated prose and base64 assets to a tiny set.
+const GOOGLE_FONTS_TEXT_MAX_ENCODED_LENGTH = 1_700;
+
+function extractGoogleFontsText(html: string): string | undefined {
+ const uniqueCharacters = [...new Set(Array.from(html))].join("");
+ return encodeURIComponent(uniqueCharacters).length <= GOOGLE_FONTS_TEXT_MAX_ENCODED_LENGTH
+ ? uniqueCharacters
+ : undefined;
+}
+
export async function injectDeterministicFontFaces(
html: string,
options: InjectDeterministicFontFacesOptions = {},
@@ -871,7 +886,11 @@ export async function injectDeterministicFontFaces(
return html;
}
- const { css, unresolved } = await buildFontFaceCss(pendingFamilies, fetchOptions);
+ const { css, unresolved } = await buildFontFaceCss(
+ pendingFamilies,
+ fetchOptions,
+ extractGoogleFontsText(html),
+ );
if (unresolved.length > 0 && options.failClosedFontFetch) {
throw new FontFetchError(
unresolved.join(", "),