From 6d886da19f2cb5ceaa651d77d25da58d111b4e53 Mon Sep 17 00:00:00 2001
From: atlas <atlas@hyperhive>
Date: Sun, 31 May 2026 01:27:25 +0200
Subject: [PATCH] nix/hive-gateway: stop SPA fallback from masking missing
 /matrix/ assets (#643)
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iris's diagnosis on #643 (mara's fluffychat-web login attempt): the gateway's
`/matrix/` location used

    try_files $uri $uri/ /matrix/index.html;

which silently returned `index.html` (Content-Type: text/html, status 200) for
ANY missing path under `/matrix/`, including static assets like
`native_executor.js`. flutter's bootstrap requested that JS file, got HTML back,
failed to load the JS runtime, and the page rendered blank without any visible
error in the browser console.

(Confirmed root cause for the missing file itself: the upstream `fluffychat-web`
dist in nixpkgs ships `native_executor.dart` but no compiled `native_executor.js`,
even though `main.dart.js` references the latter. That's a separate
fluffychat-web packaging issue — tracked separately; this PR fixes only the
gateway-side masking that hides such failures.)

Replaces the inline `try_files` fallback with a named-location fallback that
distinguishes between route-shaped URIs (no extension) and asset-shaped URIs
(any `.<ext>` suffix):

    location /matrix/ {
      alias <pkg>/;
      try_files $uri $uri/ @matrix_spa_fallback;
    }

    location @matrix_spa_fallback {
      if ($uri ~ "\.[A-Za-z0-9]+$") {
        return 404;
      }
      rewrite ^ /matrix/index.html last;
    }

Routes still fall back to `index.html` so SPA client-side routing keeps
working; missing assets now surface a real 404 so flutter (and the operator's
devtools) can see the failure.

Verified the rendered nginx location attr via
`nix eval .#nixosConfigurations.* .... locations."@matrix_spa_fallback".extraConfig`.
---
 nix/modules/hive-gateway.nix | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/nix/modules/hive-gateway.nix b/nix/modules/hive-gateway.nix
index bd461f4f..74af4d26 100644
--- a/nix/modules/hive-gateway.nix
+++ b/nix/modules/hive-gateway.nix
@@ -164,7 +164,29 @@ in
                   "/matrix/" = {
                     alias = "${matrixCfg.gui.package}/";
                     extraConfig = ''
-                      try_files $uri $uri/ /matrix/index.html;
+                      try_files $uri $uri/ @matrix_spa_fallback;
+                    '';
+                  };
+                  # SPA fallback (iris/#643). The naive
+                  # `try_files $uri $uri/ /matrix/index.html;` shape
+                  # silently masked missing static assets — flutter's
+                  # bootstrap requesting e.g. `/matrix/native_executor.js`
+                  # got `index.html` (Content-Type: text/html, status
+                  # 200) when the file was absent from the dist, so
+                  # the JS runtime never loaded and `/matrix/` rendered
+                  # blank without any visible error.
+                  #
+                  # Asset-shaped URIs (anything with a `.<ext>` segment)
+                  # get an explicit 404 so the SPA + browser see the
+                  # missing-asset error cleanly. Only route-shaped URIs
+                  # (no extension) fall through to index.html for SPA
+                  # client-side routing.
+                  "@matrix_spa_fallback" = {
+                    extraConfig = ''
+                      if ($uri ~ "\.[A-Za-z0-9]+$") {
+                        return 404;
+                      }
+                      rewrite ^ /matrix/index.html last;
                     '';
                   };
                 }