fix: refresh cached plugin translations when only a translation changes (Support#1411)

src/backend/plugins/assets.ts

@@ -76,13 +76,18 @@ export function describePluginFrontend(
   if (!plugin) return none;
 
   const locales: string[] = [];
+  const localeFiles: string[] = [];
   const dir = localesDir(plugin);
-  if (dir && fileExists(path.join(dir, "en.json"))) locales.push("en");
+  if (dir && fileExists(path.join(dir, "en.json"))) {
+    locales.push("en");
+    localeFiles.push(path.join(dir, "en.json"));
+  }
   if (dir) {
     try {
       for (const name of fs.readdirSync(path.join(dir, "translated"))) {
         if (/^[a-z]{2}_[A-Z]{2}\.json$/.test(name)) {
           locales.push(name.slice(0, -".json".length));
+          localeFiles.push(path.join(dir, "translated", name));
         }
       }
     } catch {
@@ -95,8 +100,9 @@ export function describePluginFrontend(
 
   const cssFile = path.join(entry.dir, "frontend.css");
   const css = fileExists(cssFile);
+  // Locales share the version, so a translations-only update must change it.
   const assetVersion = contentVersion(
-    css ? [entry.file, cssFile] : [entry.file],
+    [...(css ? [entry.file, cssFile] : [entry.file]), ...localeFiles.sort()],
     plugin.manifest.version,
   );
 
@@ -113,8 +119,8 @@ const versionCache = new Map<string, { stamp: string; version: string }>();
 /**
  * A hash of the bundle's bytes, not its mtime: assets are cached as immutable
  * for a year, and a rebuilt .tmxplug has a fixed mtime, so a same-size rebuild
- * would otherwise keep serving the stale copy. The CSS is hashed with the JS
+ * would otherwise keep serving the stale copy. The CSS and locales are hashed
- * because both are served under the same version.
+ * with the JS because all of them are served under the same version.
  */
 function contentVersion(files: string[], version: string): string {
   // ctime, unlike mtime, cannot be set by tar, so an unpack always changes it.

src/backend/tests/plugins/assets.test.ts

@@ -85,6 +85,23 @@ describe("describePluginFrontend", () => {
     }
   });
 
+  it("changes the version when only a translation changes", () => {
+    const before = describePluginFrontend(plugin).assetVersion;
+    const locale = path.join(
+      root,
+      "gizmo",
+      "locales",
+      "translated",
+      "de_DE.json",
+    );
+    fs.writeFileSync(locale, '{"hello":"Hallo"}');
+    try {
+      expect(describePluginFrontend(plugin).assetVersion).not.toBe(before);
+    } finally {
+      fs.writeFileSync(locale, "{}");
+    }
+  });
+
   it("reports nothing for an unknown plugin", () => {
     expect(describePluginFrontend(undefined)).toEqual({
       frontend: false,