heygen-com · miguel-heygen · Sep 30, 2026 · Sep 30, 2026 · Sep 30, 2026 · Sep 30, 2026
diff --git a/packages/studio/src/components/editor/fontAssets.test.ts b/packages/studio/src/components/editor/fontAssets.test.ts
@@ -0,0 +1,69 @@
+// @vitest-environment jsdom
+import { expect, it } from "vitest";
+import { ensureImportedFontFace, injectPreviewImportedFont } from "../../utils/studioFontHelpers";
+import { importedFontFaceCss, type ImportedFontAsset } from "./fontAssets";
+
+const face = (file: string, extra: Partial<ImportedFontAsset> = {}): ImportedFontAsset => ({
+  family: "Poppins",
+  path: `assets/fonts/Poppins/${file}`,
+  url: `/preview/assets/fonts/Poppins/${file}`,
+  ...extra,
+});
+
+it("a face with no weight or style is written as before", () => {
+  expect(importedFontFaceCss(face("Poppins-Bold.ttf"))).toBe(
+    '@font-face { font-family: "Poppins"; src: url("/preview/assets/fonts/Poppins/Poppins-Bold.ttf"); font-display: swap; }',
+  );
+});
+
+it("a face says which weight and style it draws, a variable file its weight range", () => {
+  expect(
+    importedFontFaceCss(face("Poppins-BoldItalic.ttf", { weight: "700", style: "italic" })),
+  ).toBe(
+    '@font-face { font-family: "Poppins"; src: url("/preview/assets/fonts/Poppins/Poppins-BoldItalic.ttf"); font-weight: 700; font-style: italic; font-display: swap; }',
+  );
+  expect(
+    importedFontFaceCss(face("Roboto-Variable.ttf", { weight: "100 900", style: "normal" })),
+  ).toContain("font-weight: 100 900; font-style: normal;");
+  expect(importedFontFaceCss(face("x.ttf", { weight: "700; color: red" }))).not.toContain(
+    "font-weight",
+  );
+});
+
+it("two weights of one family are both kept in the file and both drawn in the preview", () => {
+  const bold = face("Poppins-Bold.ttf", { weight: "700", style: "normal" });
+  const regular = face("Poppins-Regular.ttf", { weight: "400", style: "normal" });
+  const html = "<html><head></head><body></body></html>";
+  const saved = ensureImportedFontFace(
+    ensureImportedFontFace(html, bold, "index.html"),
+    regular,
+    "index.html",
+  );
+  expect(saved).toContain("font-weight: 700;");
+  expect(saved).toContain("font-weight: 400;");
+  expect(ensureImportedFontFace(saved, bold, "index.html")).toBe(saved);
+  injectPreviewImportedFont(document, bold);
+  injectPreviewImportedFont(document, regular);
+  injectPreviewImportedFont(document, bold);
+  expect(document.head.querySelectorAll("style")).toHaveLength(2);
+});
+
+it("a weight the browser would drop is left out, and a family cannot close the style block", () => {
+  for (const weight of ["0", "5000", "bold", "700;}"])
+    expect(importedFontFaceCss(face("x.ttf", { weight }))).not.toContain("font-weight");
+  expect(importedFontFaceCss(face("x.ttf", { weight: "1000" }))).toContain("font-weight: 1000;");
+  expect(importedFontFaceCss({ ...face("x.ttf"), family: "</style><b>x" })).not.toContain(
+    "</style>",
+  );
+});
+
+it("a file name with a replacement pattern is saved as written, not expanded into the page", () => {
+  const html = "<html><head></head><body>rest</body></html>";
+  const odd = { family: "Cash", path: "assets/Cash$'Font.ttf", url: "/Cash$'Font.ttf" };
+  const saved = ensureImportedFontFace(html, odd, "index.html");
+  expect(saved).toContain("Cash$'Font.ttf");
+  expect(saved.match(/<body>/g)).toHaveLength(1);
+  const again = ensureImportedFontFace(saved, { ...odd, path: "assets/Cash$&.ttf" }, "index.html");
+  expect(again).toContain("Cash$&.ttf");
+  expect(again.match(/<body>/g)).toHaveLength(1);
+});
diff --git a/packages/studio/src/components/editor/fontAssets.ts b/packages/studio/src/components/editor/fontAssets.ts
@@ -2,14 +2,16 @@ export interface ImportedFontAsset {
   family: string;
   path: string;
   url: string;
+  weight?: string;
+  style?: "normal" | "italic";
 }
 
 const FONT_EXT_RE = /\.(eot|otf|ttc|ttf|woff2?)$/i;
 const FONT_STYLE_SUFFIX_RE =
   /\s+(thin|extralight|extra light|light|regular|roman|medium|semibold|semi bold|bold|extrabold|extra bold|black|italic|oblique|variable)$/i;
 
 function cssString(value: string): string {
-  return JSON.stringify(value);
+  return JSON.stringify(value).replace(/</g, "\\3c ");
 }
 
 export function fontFamilyFromAssetPath(path: string): string {
@@ -28,5 +30,12 @@ export function fontFamilyFromAssetPath(path: string): string {
 }
 
 export function importedFontFaceCss(asset: ImportedFontAsset, url: string = asset.url): string {
-  return `@font-face { font-family: ${cssString(asset.family)}; src: url(${cssString(url)}); font-display: swap; }`;
+  const weight =
+    asset.weight && /^(?:[1-9]\d{0,2}|1000)(?: (?:[1-9]\d{0,2}|1000))?$/.test(asset.weight)
+      ? ` font-weight: ${asset.weight};`
+      : "";
+  const style = asset.style
+    ? ` font-style: ${asset.style === "italic" ? "italic" : "normal"};`
+    : "";
+  return `@font-face { font-family: ${cssString(asset.family)}; src: url(${cssString(url)});${weight}${style} font-display: swap; }`;
 }
diff --git a/packages/studio/src/hooks/domStyleCommit.fonts.test.ts b/packages/studio/src/hooks/domStyleCommit.fonts.test.ts
@@ -0,0 +1,55 @@
+// @vitest-environment jsdom
+import { expect, it } from "vitest";
+import type { DomEditSelection } from "../components/editor/domEditing";
+import type { ImportedFontAsset } from "../components/editor/fontAssets";
+import { commitDomStyles, type DomStyleCommitContext } from "./domStyleCommit";
+
+const selection = (id: string): DomEditSelection =>
+  ({
+    id,
+    selector: `#${id}`,
+    label: id,
+    tagName: "p",
+    sourceFile: "index.html",
+    compositionPath: "index.html",
+    textFields: [],
+    inlineStyles: {},
+    computedStyles: {},
+    dataAttributes: {},
+    capabilities: { canSelect: true, canEditStyles: true },
+  }) as unknown as DomEditSelection;
+
+const poppins = (file: string, weight: string): ImportedFontAsset => ({
+  family: "Poppins",
+  path: `assets/fonts/Poppins/${file}`,
+  url: `/preview/assets/fonts/Poppins/${file}`,
+  weight,
+  style: "normal",
+});
+
+it("each font a host hands over is saved as its own face, with the weight and style it draws", async () => {
+  let html = '<html><head></head><body><h1 id="title"></h1><p id="subtitle"></p></body></html>';
+  let listed: ImportedFontAsset | null = null;
+  const context: DomStyleCommitContext = {
+    activeCompPath: "index.html",
+    previewIframeRef: { current: null },
+    showToast: () => undefined,
+    versions: new Map(),
+    resolveImportedFontAsset: () => listed,
+    persistDomEditOperations: (async (
+      _selection: DomEditSelection,
+      _operations: unknown,
+      options?: { prepareContent?: (html: string, sourceFile: string) => string },
+    ) => {
+      html = options?.prepareContent?.(html, "index.html") ?? html;
+    }) as unknown as DomStyleCommitContext["persistDomEditOperations"],
+  };
+  listed = poppins("Poppins-SemiBold.ttf", "600");
+  await commitDomStyles(context, selection("title"), { "font-family": "Poppins" });
+  listed = poppins("Poppins-Regular.ttf", "400");
+  await commitDomStyles(context, selection("subtitle"), { "font-family": "Poppins" });
+  const faces = html.match(/@font-face[^}]*}/g) ?? [];
+  expect(faces).toHaveLength(2);
+  expect(faces[0]).toContain('Poppins-SemiBold.ttf"); font-weight: 600; font-style: normal;');
+  expect(faces[1]).toContain('Poppins-Regular.ttf"); font-weight: 400; font-style: normal;');
+});
diff --git a/packages/studio/src/utils/studioFontHelpers.ts b/packages/studio/src/utils/studioFontHelpers.ts
@@ -52,7 +52,7 @@ export function injectPreviewGoogleFont(doc: Document, fontFamilyValue: string):
 }
 
 export function injectPreviewImportedFont(doc: Document, asset: ImportedFontAsset): void {
-  const id = `studio-imported-font-${asset.family.toLowerCase().replace(/[^a-z0-9]+/g, "-")}`;
+  const id = `studio-imported-font-${asset.path.toLowerCase().replace(/[^a-z0-9]+/g, "-")}`;
   if (doc.getElementById(id)) return;
   const style = doc.createElement("style");
   style.id = id;
@@ -72,12 +72,15 @@ export function ensureImportedFontFace(
   const styleMatch = styleRe.exec(html);
   if (styleMatch) {
     const nextCss = `${styleMatch[2].trim()}\n${css}`.trim();
-    return html.replace(styleMatch[0], `<style data-hf-studio-fonts="true">\n${nextCss}\n</style>`);
+    return html.replace(
+      styleMatch[0],
+      () => `<style data-hf-studio-fonts="true">\n${nextCss}\n</style>`,
+    );
   }
 
   const styleTag = `<style data-hf-studio-fonts="true">\n${css}\n</style>`;
   if (/<\/head>/i.test(html)) {
-    return html.replace(/<\/head>/i, `  ${styleTag}\n  </head>`);
+    return html.replace(/<\/head>/i, () => `  ${styleTag}\n  </head>`);
   }
   return `${styleTag}\n${html}`;
 }