build(fonts): self-host Inter so the build fetches nothing

next/font/google downloads Inter from fonts.googleapis.com and fonts.gstatic.com while the app builds, and when that request fails the build fails with it, which is what broke the arm64 image build and several CI jobs. The files it downloaded now live in src/app/fonts/inter under the SIL Open Font License, and next/font/local declares them. They are the same bytes: Inter 4.001, one variable file per script subset (Cyrillic and its extension, Greek and its extension, Vietnamese, Latin Extended, Latin), each used for weights 400 to 700. The declarations rebuild the stylesheet Google answered, the twenty-eight faces with Google's unicode ranges in Google's subset order, swap display, and only the Latin file preloaded. The local loader emits one unicode range per call, so each subset is its own call under the family Inter. The Arial fallback face and the font-sans stack move into globals.css with the metric overrides next/font/google shipped for Inter; the local loader would have computed slightly different ones from the file. A production build with every outbound request sent to a dead proxy completes, where the same build with next/font/google fails on the fonts.googleapis.com request. The content security policy already allowed fonts from self only. A guard refuses a next/font/google import anywhere under src.
2026-11-12 06:06:10 +00:00 · 2026-10-22 07:31:16 +02:00
1 parent eda90eeb56
commit 5d3794e734
@@ -0,0 +1,58 @@
+/**
+ * The build fetches no font from the network.
+ *
+ * `next/font/google` downloads its files from fonts.gstatic.com while the app
+ * builds, and that download failing is what broke image builds. Inter is
+ * committed under `src/app/fonts/inter/` instead, under its licence, and
+ * declared through `next/font/local`. This guard keeps it that way: no source
+ * file imports the Google loader, every file the local declarations name is
+ * in the tree, and each subset carries the four weights the app was built
+ * with.
+ *
+ * Mutation check: importing `Inter` from the Google loader anywhere under
+ * `src/` fails the first case; deleting a `.woff2` or dropping a weight from a
+ * subset fails the second.
+ */
+import { existsSync } from "node:fs";
+import { dirname, join } from "node:path";
+
+import { describe, expect, it } from "vitest";
+
+import { readSource, readSourceFolder } from "./helpers/source-files";
+
+const ROOT = process.cwd();
+const FONT_MODULE = "src/app/fonts/inter.ts";
+
+describe("self-hosted fonts", () => {
+  it("imports no font loader that downloads at build time", () => {
+    const importing = readSourceFolder("src", {
+      floor: 3000,
+      include: (rel) => !rel.startsWith("generated/"),
+      extensions: [".ts", ".tsx", ".mts", ".js", ".mjs"],
+    })
+      .filter(([, text]) => /from\s+["']next\/font\/google["']/.test(text))
+      .map(([rel]) => rel);
+    expect(importing).toEqual([]);
+  });
+
+  it("ships every file the declarations name, with its licence and four weights", () => {
+    const source = readSource(FONT_MODULE, ["next/font/local", "localFont("]);
+    const entries = [
+      ...source.matchAll(/path:\s*"([^"]+)",\s*weight:\s*"(\d+)"/g),
+    ].map(([, path, weight]) => ({ path: path!, weight: weight! }));
+    expect(entries.length).toBe(28);
+
+    const byFile = new Map<string, string[]>();
+    for (const { path, weight } of entries) {
+      byFile.set(path, [...(byFile.get(path) ?? []), weight]);
+    }
+    expect(byFile.size).toBe(7);
+    for (const [path, weights] of byFile) {
+      expect(existsSync(join(ROOT, dirname(FONT_MODULE), path)), path).toBe(
+        true,
+      );
+      expect(weights, path).toEqual(["400", "500", "600", "700"]);
+    }
+    expect(existsSync(join(ROOT, "src/app/fonts/inter/OFL.txt"))).toBe(true);
+  });
+});
@@ -0,0 +1,177 @@
+/**
+ * Inter, self-hosted. The build fetches nothing from the network for it.
+ *
+ * These are the files `next/font/google` used to download at build time for
+ * `Inter({ subsets: ["latin"], weight: ["400", "500", "600", "700"] })`,
+ * byte for byte: Google serves Inter 4.001 as one variable file per script
+ * subset, the same file for every weight. That download failed often enough
+ * to break image builds, so the files live here under their licence
+ * (`./inter/OFL.txt`) and the declarations below rebuild the stylesheet
+ * Google answered: twenty-eight faces, the four weights for each of the seven
+ * subsets with Google's `unicode-range`s, in Google's order (where two ranges
+ * overlap the face declared later wins, so the order is part of the result),
+ * `font-display: swap`, and only the Latin file preloaded.
+ *
+ * `next/font/local` emits one `unicode-range` per call, hence one call per
+ * subset, all declaring the family `Inter`. The fallback face and the
+ * `--font-sans` stack are in `globals.css`: the local loader would derive the
+ * Arial metric overrides from the font file, and they come out a little
+ * different from the ones next/font/google shipped, which are kept as they
+ * were.
+ *
+ * Imported by the root layout for its stylesheet only.
+ */
+import localFont from "next/font/local";
+
+// `next/font/local` is evaluated at build time from the literal arguments of
+// each call, so every option below has to be written out in place.
+export const interCyrillicExt = localFont({
+  src: [
+    {
+      path: "./inter/inter-cyrillic-ext.woff2",
+      weight: "400",
+      style: "normal",
+    },
+    {
+      path: "./inter/inter-cyrillic-ext.woff2",
+      weight: "500",
+      style: "normal",
+    },
+    {
+      path: "./inter/inter-cyrillic-ext.woff2",
+      weight: "600",
+      style: "normal",
+    },
+    {
+      path: "./inter/inter-cyrillic-ext.woff2",
+      weight: "700",
+      style: "normal",
+    },
+  ],
+  display: "swap",
+  preload: false,
+  adjustFontFallback: false,
+  declarations: [
+    { prop: "font-family", value: "Inter" },
+    {
+      prop: "unicode-range",
+      value:
+        "U+0460-052F, U+1C80-1C8A, U+20B4, U+2DE0-2DFF, U+A640-A69F, U+FE2E-FE2F",
+    },
+  ],
+});
+
+export const interCyrillic = localFont({
+  src: [
+    { path: "./inter/inter-cyrillic.woff2", weight: "400", style: "normal" },
+    { path: "./inter/inter-cyrillic.woff2", weight: "500", style: "normal" },
+    { path: "./inter/inter-cyrillic.woff2", weight: "600", style: "normal" },
+    { path: "./inter/inter-cyrillic.woff2", weight: "700", style: "normal" },
+  ],
+  display: "swap",
+  preload: false,
+  adjustFontFallback: false,
+  declarations: [
+    { prop: "font-family", value: "Inter" },
+    {
+      prop: "unicode-range",
+      value: "U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116",
+    },
+  ],
+});
+
+export const interGreekExt = localFont({
+  src: [
+    { path: "./inter/inter-greek-ext.woff2", weight: "400", style: "normal" },
+    { path: "./inter/inter-greek-ext.woff2", weight: "500", style: "normal" },
+    { path: "./inter/inter-greek-ext.woff2", weight: "600", style: "normal" },
+    { path: "./inter/inter-greek-ext.woff2", weight: "700", style: "normal" },
+  ],
+  display: "swap",
+  preload: false,
+  adjustFontFallback: false,
+  declarations: [
+    { prop: "font-family", value: "Inter" },
+    { prop: "unicode-range", value: "U+1F00-1FFF" },
+  ],
+});
+
+export const interGreek = localFont({
+  src: [
+    { path: "./inter/inter-greek.woff2", weight: "400", style: "normal" },
+    { path: "./inter/inter-greek.woff2", weight: "500", style: "normal" },
+    { path: "./inter/inter-greek.woff2", weight: "600", style: "normal" },
+    { path: "./inter/inter-greek.woff2", weight: "700", style: "normal" },
+  ],
+  display: "swap",
+  preload: false,
+  adjustFontFallback: false,
+  declarations: [
+    { prop: "font-family", value: "Inter" },
+    {
+      prop: "unicode-range",
+      value:
+        "U+0370-0377, U+037A-037F, U+0384-038A, U+038C, U+038E-03A1, U+03A3-03FF",
+    },
+  ],
+});
+
+export const interVietnamese = localFont({
+  src: [
+    { path: "./inter/inter-vietnamese.woff2", weight: "400", style: "normal" },
+    { path: "./inter/inter-vietnamese.woff2", weight: "500", style: "normal" },
+    { path: "./inter/inter-vietnamese.woff2", weight: "600", style: "normal" },
+    { path: "./inter/inter-vietnamese.woff2", weight: "700", style: "normal" },
+  ],
+  display: "swap",
+  preload: false,
+  adjustFontFallback: false,
+  declarations: [
+    { prop: "font-family", value: "Inter" },
+    {
+      prop: "unicode-range",
+      value:
+        "U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB",
+    },
+  ],
+});
+
+export const interLatinExt = localFont({
+  src: [
+    { path: "./inter/inter-latin-ext.woff2", weight: "400", style: "normal" },
+    { path: "./inter/inter-latin-ext.woff2", weight: "500", style: "normal" },
+    { path: "./inter/inter-latin-ext.woff2", weight: "600", style: "normal" },
+    { path: "./inter/inter-latin-ext.woff2", weight: "700", style: "normal" },
+  ],
+  display: "swap",
+  preload: false,
+  adjustFontFallback: false,
+  declarations: [
+    { prop: "font-family", value: "Inter" },
+    {
+      prop: "unicode-range",
+      value:
+        "U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF",
+    },
+  ],
+});
+
+export const interLatin = localFont({
+  src: [
+    { path: "./inter/inter-latin.woff2", weight: "400", style: "normal" },
+    { path: "./inter/inter-latin.woff2", weight: "500", style: "normal" },
+    { path: "./inter/inter-latin.woff2", weight: "600", style: "normal" },
+    { path: "./inter/inter-latin.woff2", weight: "700", style: "normal" },
+  ],
+  display: "swap",
+  preload: true,
+  adjustFontFallback: false,
+  declarations: [
+    { prop: "font-family", value: "Inter" },
+    {
+      prop: "unicode-range",
+      value:
+        "U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD",
+    },
+  ],
+});
@@ -0,0 +1,93 @@
+Copyright 2020 The Inter Project Authors (https://github.com/rsms/inter)
+
+This Font Software is licensed under the SIL Open Font License, Version 1.1.
+This license is copied below, and is also available with a FAQ at:
+https://scripts.sil.org/OFL
+
+
+-----------------------------------------------------------
+SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
+-----------------------------------------------------------
+
+PREAMBLE
+The goals of the Open Font License (OFL) are to stimulate worldwide
+development of collaborative font projects, to support the font creation
+efforts of academic and linguistic communities, and to provide a free and
+open framework in which fonts may be shared and improved in partnership
+with others.
+
+The OFL allows the licensed fonts to be used, studied, modified and
+redistributed freely as long as they are not sold by themselves. The
+fonts, including any derivative works, can be bundled, embedded, 
+redistributed and/or sold with any software provided that any reserved
+names are not used by derivative works. The fonts and derivatives,
+however, cannot be released under any other type of license. The
+requirement for fonts to remain under this license does not apply
+to any document created using the fonts or their derivatives.
+
+DEFINITIONS
+"Font Software" refers to the set of files released by the Copyright
+Holder(s) under this license and clearly marked as such. This may
+include source files, build scripts and documentation.
+
+"Reserved Font Name" refers to any names specified as such after the
+copyright statement(s).
+
+"Original Version" refers to the collection of Font Software components as
+distributed by the Copyright Holder(s).
+
+"Modified Version" refers to any derivative made by adding to, deleting,
+or substituting -- in part or in whole -- any of the components of the
+Original Version, by changing formats or by porting the Font Software to a
+new environment.
+
+"Author" refers to any designer, engineer, programmer, technical
+writer or other person who contributed to the Font Software.
+
+PERMISSION & CONDITIONS
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Font Software, to use, study, copy, merge, embed, modify,
+redistribute, and sell modified and unmodified copies of the Font
+Software, subject to the following conditions:
+
+1) Neither the Font Software nor any of its individual components,
+in Original or Modified Versions, may be sold by itself.
+
+2) Original or Modified Versions of the Font Software may be bundled,
+redistributed and/or sold with any software, provided that each copy
+contains the above copyright notice and this license. These can be
+included either as stand-alone text files, human-readable headers or
+in the appropriate machine-readable metadata fields within text or
+binary files as long as those fields can be easily viewed by the user.
+
+3) No Modified Version of the Font Software may use the Reserved Font
+Name(s) unless explicit written permission is granted by the corresponding
+Copyright Holder. This restriction only applies to the primary font name as
+presented to the users.
+
+4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+Software shall not be used to promote, endorse or advertise any
+Modified Version, except to acknowledge the contribution(s) of the
+Copyright Holder(s) and the Author(s) or with their explicit written
+permission.
+
+5) The Font Software, modified or unmodified, in part or in whole,
+must be distributed entirely under this license, and must not be
+distributed under any other license. The requirement for fonts to
+remain under this license does not apply to any document created
+using the Font Software.
+
+TERMINATION
+This license becomes null and void if any of the above conditions are
+not met.
+
+DISCLAIMER
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM
+OTHER DEALINGS IN THE FONT SOFTWARE.
@@ -30,6 +30,28 @@
@source not "../../.planning";
@source not "../../docs";

+/*
+ * Inter's fallback and the font-sans stack. The Inter faces themselves come
+ * from `./fonts/inter.ts`. This is what next/font/google generated for Inter
+ * when it still fetched the font at build time: Arial, scaled with the metric
+ * overrides it shipped for Inter, so text keeps its box while the web font
+ * loads. They are written out here because next/font/local would compute its
+ * own, slightly different overrides from the font file.
+ */
+@font-face {
+  font-family: "Inter Fallback";
+  src: local("Arial");
+  ascent-override: 90.44%;
+  descent-override: 22.52%;
+  line-gap-override: 0%;
+  size-adjust: 107.12%;
+}
+
+/* On body, where the next/font variable class used to set it. */
+body {
+  --font-sans: "Inter", "Inter Fallback";
+}
+
@custom-variant dark (&:is(.dark *));

 /*
@@ -1,7 +1,9 @@
 import type { Metadata, Viewport } from "next";
-import { Inter } from "next/font/google";
 import { headers } from "next/headers";
 import Script from "next/script";
+// Inter's faces, self-hosted; see the module. Before globals.css, where the
+// font-sans stack that names them lives, as the next/font/google import was.
+import "./fonts/inter";
 import "./globals.css";
 import { Providers } from "@/components/providers";
 import { AuthShell } from "@/components/layout/auth-shell";
@@ -12,12 +14,6 @@ import { isKeyMismatch } from "@/lib/boot/key-mismatch-state";
 import { THEME_BOOT_SCRIPT, THEME_COLOR } from "@/lib/pwa/theme-color";
 import { KeyMismatchPage } from "./key-mismatch-page";

-const inter = Inter({
-  variable: "--font-sans",
-  subsets: ["latin"],
-  weight: ["400", "500", "600", "700"],
-});
-
 export const metadata: Metadata = {
  title: "HealthLog",
  description:
@@ -136,7 +132,7 @@ export default async function RootLayout({
          src={`/i18n/${initialLocale}.js?v=${process.env.NEXT_PUBLIC_I18N_CATALOG_VERSION || "dev"}`}
        />
      </head>
-      <body className={`${inter.variable} font-sans antialiased`}>
+      <body className="font-sans antialiased">
        {isKeyMismatch() ? (
          // The boot key check refused this process: no app shell, no data
          // reads, one page that names the fix.
@@ -23,9 +23,10 @@ import { primeLocales } from "@/__tests__/helpers/prime-locales";
 * REAL compiled stylesheet, lays it out in a browser at the real column
 * width, and reads the boxes back.
 *
- * What it does NOT do is pretend to know the shipped typeface. The app loads
- * Inter through `next/font/google` at build time; no font file is committed,
- * so a headless browser here resolves the `font-sans` fallback chain instead.
+ * What it does NOT do is pretend to know the shipped typeface. The app's Inter
+ * faces are declared through `next/font/local` (`src/app/fonts/inter.ts`) and
+ * only exist in a Next build, so a headless browser here resolves the
+ * `font-sans` fallback chain instead.
 * Every assertion below is therefore written to be font-independent — a
 * relative comparison inside one run, or a structural property (does the row
 * push, does the label ellipsise, is the bar still there) that holds in any