From 67f54347b2ca711f40495fa7fcb05e132ea8f3da Mon Sep 17 00:00:00 2001
From: SnapOtter <snapotter.hq@gmail.com>
Date: Sat, 18 Jul 2026 10:47:53 +0800
Subject: [PATCH] fix(landing): keep mixed-case locale casing in emitted URLs
 (#562)

Astro's getRelativeLocaleUrl lowercases the locale segment by default, so landing links and hreflang for zh-CN, zh-TW, and pt-BR were emitted lowercase and 404 on case-sensitive Cloudflare Pages. Pin the casing at the localizeHref chokepoint with normalizeLocale: false, add an e2e hreflang casing guard, and add a deploy-time check that blocks the build if any lowercased locale path leaks into the output.

Closes #554
---
 .github/workflows/deploy-landing.yml   | 28 ++++++++++++++++++++++++++
 apps/landing/src/lib/i18n-page.ts      |  9 ++++++++-
 tests/e2e-landing/i18n-seo-rtl.spec.ts | 20 ++++++++++++++++++
 3 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/deploy-landing.yml b/.github/workflows/deploy-landing.yml
index 2ddf3e4a..bf48bcdd 100644
--- a/.github/workflows/deploy-landing.yml
+++ b/.github/workflows/deploy-landing.yml
@@ -33,6 +33,34 @@ jobs:
           # fetch isn't rate-limited on shared runner IPs (60 req/hr unauth).
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
+      # Astro's getRelativeLocaleUrl lowercases locale segments by default, so a
+      # regression could re-emit /zh-cn/ etc. in hrefs and hreflang. Those 404 on
+      # case-sensitive Cloudflare Pages while the built dirs + sitemap keep canonical
+      # mixed case, and the mismatch is invisible on a case-insensitive dev machine.
+      # Fail the deploy if any lowercased variant of a mixed-case locale directory
+      # leaks into the emitted HTML. See #554.
+      - name: Guard against lowercased locale URLs
+        run: |
+          set -uo pipefail
+          dist=apps/landing/dist
+          fail=0
+          for dir in "$dist"/*/; do
+            name=$(basename "$dir")
+            lower=$(printf '%s' "$name" | tr '[:upper:]' '[:lower:]')
+            [ "$name" = "$lower" ] && continue
+            hits=$(grep -rIl --include='*.html' "/$lower/" "$dist" || true)
+            if [ -n "$hits" ]; then
+              echo "::error::Lowercased locale path /$lower/ found in built HTML (canonical is /$name/); it would 404 on Cloudflare Pages. See #554."
+              printf '%s\n' "$hits" | head -5
+              fail=1
+            fi
+          done
+          if [ "$fail" -ne 0 ]; then
+            echo "Deploy blocked: lowercased locale URLs would 404 on case-sensitive hosting."
+            exit 1
+          fi
+          echo "Locale URL casing OK: no lowercased locale paths in built output."
+
       - name: Deploy to Cloudflare Pages
         run: npx wrangler pages deploy apps/landing/dist --project-name snapotter-landing --branch main --commit-dirty=true
         env:
diff --git a/apps/landing/src/lib/i18n-page.ts b/apps/landing/src/lib/i18n-page.ts
index e18c0354..26ae1131 100644
--- a/apps/landing/src/lib/i18n-page.ts
+++ b/apps/landing/src/lib/i18n-page.ts
@@ -10,13 +10,20 @@ export const SITE = "https://snapotter.com";
  * A trailing "#hash" is split off first and reattached untouched, since
  * Astro's URL builder would otherwise treat it as part of the path and
  * mangle it with a trailing slash (e.g. "/#pricing" -> "/#pricing/").
+ *
+ * `normalizeLocale: false` keeps the locale segment identical to its code.
+ * By default Astro lowercases it (getRelativeLocaleUrl runs normalizeTheLocale,
+ * so "zh-CN" -> "zh-cn", "pt-BR" -> "pt-br"), but our routes are built from the
+ * raw codes (getStaticPaths -> /zh-CN/, /pt-BR/) and the sitemap keeps that same
+ * mixed case. The lowercased links resolve fine on case-insensitive local hosting
+ * but 404 on case-sensitive hosts like Cloudflare Pages, so we pin the casing here.
  */
 export function localizeHref(locale: string, path: string): string {
   const hashIndex = path.indexOf("#");
   const pathname = hashIndex === -1 ? path : path.slice(0, hashIndex);
   const hash = hashIndex === -1 ? "" : path.slice(hashIndex);
   const clean = pathname.startsWith("/") ? pathname.slice(1) : pathname;
-  return `${getRelativeLocaleUrl(locale, clean)}${hash}`;
+  return `${getRelativeLocaleUrl(locale, clean, { normalizeLocale: false })}${hash}`;
 }
 
 /**
diff --git a/tests/e2e-landing/i18n-seo-rtl.spec.ts b/tests/e2e-landing/i18n-seo-rtl.spec.ts
index 8eb6a1a7..1e672b88 100644
--- a/tests/e2e-landing/i18n-seo-rtl.spec.ts
+++ b/tests/e2e-landing/i18n-seo-rtl.spec.ts
@@ -24,6 +24,26 @@ test.describe("landing hreflang, RTL, and banner", () => {
     expect(enFromDe).toBe("https://snapotter.com/faq/");
   });
 
+  // Regression guard for #554. Astro's getRelativeLocaleUrl lowercases the locale
+  // segment by default (normalizeTheLocale: "zh-CN" -> "zh-cn"), but the built
+  // directories and the sitemap keep canonical mixed case. The lowercased links
+  // resolve on case-insensitive local hosting but 404 on Cloudflare Pages. This
+  // reads the emitted href string, so it catches the mismatch regardless of the
+  // local filesystem's case sensitivity (which is why the specs above missed it).
+  test("mixed-case locales keep their exact casing in hreflang links", async ({ page }) => {
+    await page.goto("/faq");
+    for (const code of ["zh-CN", "zh-TW", "pt-BR"]) {
+      const href = await page
+        .locator(`link[rel="alternate"][hreflang="${code}"]`)
+        .getAttribute("href");
+      expect(href, `hreflang ${code} must preserve casing`).toBe(
+        `https://snapotter.com/${code}/faq/`,
+      );
+      // The lowercased path (the bug) must not appear.
+      expect(href).not.toContain(code.toLowerCase());
+    }
+  });
+
   test("Arabic renders dir=rtl on <html>", async ({ page }) => {
     await page.goto("/ar/faq");
     await expect(page.locator("html")).toHaveAttribute("dir", "rtl");