Force redirects with conditions before plain redirects

Author: FinnWoelm

lib/helpers/getSortedRedirects.js

@@ -0,0 +1,35 @@
+const {
+  getSortedRoutes: getSortedRoutesFromNext,
+} = require("next/dist/next-server/lib/router/utils/sorted-routes");
+
+// Remove the file extension form the route
+const removeFileExtension = (route) => route.replace(/\.[a-zA-Z]+$/, "");
+
+// Return an array of redirects sorted in order of specificity, i.e., more generic
+// routes precede more specific ones
+const getSortedRedirects = (redirects) => {
+  // The @sls-next getSortedRoutes does not correctly sort routes with file
+  // endings (e.g., json), so we remove them before sorting and add them back
+  // after sorting
+  const routesWithoutExtensions = redirects.map(({ route }) =>
+    removeFileExtension(route)
+  );
+
+  // Sort the "naked" routes
+  const sortedRoutes = getSortedRoutesFromNext(routesWithoutExtensions);
+
+  // Return original routes in the sorted order
+  return redirects.sort((a, b) => {
+    // If routes are different, sort according to Next.js' getSortedRoutes
+    if (a.route !== b.route) {
+      return (
+        sortedRoutes.indexOf(removeFileExtension(a.route)) -
+        sortedRoutes.indexOf(removeFileExtension(b.route))
+      );
+    }
+    // Otherwise, put the route with more conditions first
+    return (b.conditions || []).length - (a.conditions || []).length;
+  });
+};
+
+module.exports = getSortedRedirects;

lib/helpers/getSortedRoutes.js

@@ -5,7 +5,7 @@ const {
   CUSTOM_REDIRECTS_PATH,
   NEXT_IMAGE_FUNCTION_NAME,
 } = require("../config");
-const getSortedRoutes = require("../helpers/getSortedRoutes");
+const getSortedRedirects = require("../helpers/getSortedRedirects");
 const getNetlifyRoutes = require("../helpers/getNetlifyRoutes");
 const isRootCatchAllRedirect = require("../helpers/isRootCatchAllRedirect");
 const isDynamicRoute = require("../helpers/isDynamicRoute");
@@ -49,13 +49,6 @@ const setupRedirects = (publishPath) => {
     target: `/.netlify/functions/${NEXT_IMAGE_FUNCTION_NAME}?url=:url&w=:width&q=:quality`,
   });
 
-  // Sort routes: More-specific routes precede less-specific routes (e.g., catch-all)
-  const getSortedRedirects = (redirects) => {
-    const sortedRoutes = getSortedRoutes(redirects.map(({ route }) => route));
-    return redirects.sort(
-      (a, b) => sortedRoutes.indexOf(a.route) - sortedRoutes.indexOf(b.route)
-    );
-  };
   const sortedStaticRedirects = getSortedRedirects(staticRedirects);
   const sortedDynamicRedirects = getSortedRedirects(dynamicRedirects);