fix(socialMeta): coerced numeric/boolean override silently dropped

src/node/utils/Settings.ts

@@ -166,7 +166,13 @@ export type SettingsType = {
   favicon: string | null,
   publicURL: string | null,
   socialMeta: {
-    description: string | null,
+    // Runtime type is wider than what an operator writes by hand: when
+    // `socialMeta.description` is sourced from an env var (e.g.
+    // `"${SOCIAL_META_DESCRIPTION:null}"` in settings.json.docker), the
+    // settings loader's `coerceValue()` turns numeric-looking strings into
+    // numbers and "true"/"false" into booleans. Downstream code stringifies
+    // before use; the wider type stops callers (and tests) needing casts.
+    description: string | number | boolean | null,
   },
   ttl: {
     AccessToken: number,

src/node/utils/socialMeta.ts

@@ -102,7 +102,11 @@ type SocialMetaSettings = {
   favicon?: string | null,
   publicURL?: string | null,
   socialMeta?: {
-    description?: string | null,
+    // Wider than the operator-facing type: env-var-driven settings get
+    // pre-coerced by Settings.coerceValue(), so we may receive number/boolean
+    // even though "the value an operator types" is a string. Stringified at
+    // resolve time.
+    description?: string | number | boolean | null,
   },
 };
 
@@ -161,16 +165,21 @@ export type RenderOpts = {
   padName?: string,
 };
 
-// Operator override wins, but only when it's a non-empty string. An empty
-// string from settings would silently blank out og:description / twitter:
-// description and break previews, so we treat empty/whitespace-only as unset
-// and fall back to the i18n catalog.
+// Operator override wins when set. Settings.ts coerces env-var strings to
+// their typed form (e.g. SOCIAL_META_DESCRIPTION="123" arrives as the number
+// 123 and ="true" as the boolean true), so we accept string | number | boolean
+// and stringify before comparing. Empty / whitespace-only values are treated
+// as unset — an accidental "" in settings would otherwise silently blank out
+// og:description and break previews entirely.
 const resolveDescriptionWithOverride = (
-  override: string | null | undefined,
+  override: string | number | boolean | null | undefined,
   locales: {[lang: string]: {[key: string]: string}} | undefined,
   renderLang: string,
 ): string => {
-  if (typeof override === 'string' && override.trim() !== '') return override;
+  if (override !== null && override !== undefined) {
+    const s = String(override);
+    if (s.trim() !== '') return s;
+  }
   return resolveDescription(locales, renderLang);
 };
 

src/tests/backend/specs/socialMeta-unit.ts

@@ -249,6 +249,38 @@ describe(__filename, function () {
       });
       assert.equal(ogTag(html, 'og:description'), 'Catalog');
     });
+
+    it('numeric override is stringified (env-var coercion safety)', function () {
+      // Settings.ts coerceValue() turns numeric-looking env vars into numbers,
+      // so SOCIAL_META_DESCRIPTION="2026" arrives here as the number 2026.
+      // Without stringification the resolver would silently fall back to i18n.
+      const html = renderSocialMeta({
+        req: fakeReq(),
+        settings: {
+          title: 'Etherpad', favicon: null,
+          socialMeta: {description: 2026},
+        },
+        availableLangs: {en: {}}, locales: enLocales,
+        kind: 'pad', padName: 'P',
+      });
+      assert.equal(ogTag(html, 'og:description'), '2026');
+    });
+
+    it('boolean override is stringified (covers "true"/"false" env-var coercion)', function () {
+      // Less likely than the numeric case but possible: setting
+      // SOCIAL_META_DESCRIPTION="true" yields a boolean. Treat it like the
+      // operator wrote that literal string rather than silently dropping it.
+      const html = renderSocialMeta({
+        req: fakeReq(),
+        settings: {
+          title: 'Etherpad', favicon: null,
+          socialMeta: {description: true},
+        },
+        availableLangs: {en: {}}, locales: enLocales,
+        kind: 'pad', padName: 'P',
+      });
+      assert.equal(ogTag(html, 'og:description'), 'true');
+    });
   });
 
   describe('renderSocialMeta — image URL', function () {