From 89940b105fc31c2b246f6a82f3aea10b80b439ab Mon Sep 17 00:00:00 2001
From: Doxa Maps <maps@doxa.example>
Date: Mon, 28 Sep 2026 21:52:20 +0000
Subject: [PATCH] EMBED_BASE_URL overrides the committed embedBaseUrl for a
 host's own tree build

A host that builds its own tree (maps-dev's /cdn build inherits the container env) can bake
absolute embed snippet URLs without a committed config change, the same pattern as
DOXA_SYNC_PATHS. The value is the base without the tree name; a trailing slash is trimmed.
check-embed-targets-exist reads the same effective base. Unset, the tree is byte-identical.
---
 internal/check-embed-targets-exist.mjs | 3 ++-
 internal/generate-tree.mjs             | 7 ++++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/internal/check-embed-targets-exist.mjs b/internal/check-embed-targets-exist.mjs
index d48a94050..ef9328e0d 100644
--- a/internal/check-embed-targets-exist.mjs
+++ b/internal/check-embed-targets-exist.mjs
@@ -63,7 +63,8 @@ function collectIframeSrcs(manifest) {
 function resolveSrc(src) {
   const noQuery = src.split('?')[0].split('#')[0]
   if (/^(https?:)?\/\//i.test(noQuery)) {
-    const base = CFG.embedBaseUrl || ''
+    // The same effective base generate-tree bakes: EMBED_BASE_URL wins over the committed config.
+    const base = ((process.env.EMBED_BASE_URL || '').trim() || CFG.embedBaseUrl || '').replace(/\/+$/, '')
     if (!base || !noQuery.startsWith(base)) return { kind: 'skip', reason: 'off-site absolute URL' }
     let rest = noQuery.slice(base.length).replace(/^\/+/, '')
     if (rest.startsWith(TREE + '/')) rest = rest.slice(TREE.length + 1)
diff --git a/internal/generate-tree.mjs b/internal/generate-tree.mjs
index 1630bb043..70031aa93 100644
--- a/internal/generate-tree.mjs
+++ b/internal/generate-tree.mjs
@@ -73,7 +73,12 @@ function readBuildConfig() {
         if (!paths.includes(p)) paths.push(p)
       }
     }
-    const embedBaseUrl = (typeof cfg.embedBaseUrl === 'string' ? cfg.embedBaseUrl.trim() : '').replace(/\/+$/, '')
+    // EMBED_BASE_URL overrides the committed embedBaseUrl, the same way DOXA_SYNC_PATHS extends paths:
+    // a host that builds its own tree (maps-dev's /cdn build inherits the container env) bakes absolute
+    // snippet URLs without a committed config change. It is the base WITHOUT the tree name
+    // (https://maps-dev.nuxtbase.app/cdn -> .../cdn/<name>/...). check-embed-targets-exist reads the same.
+    const embedBaseUrl = ((process.env.EMBED_BASE_URL || '').trim()
+      || (typeof cfg.embedBaseUrl === 'string' ? cfg.embedBaseUrl.trim() : '')).replace(/\/+$/, '')
     const tokenUrl = typeof cfg.tokenUrl === 'string' ? cfg.tokenUrl.trim() : ''
     // OPT-IN baked token (token ladder rung 3): a literal Mapbox token inlined into
     // every generated page. Empty by default — prefer tokenUrl (a URL, not a secret).