fix: Add helpful error messages for invalid wildcard routes in Express v5

lib/application.js

@@ -219,7 +219,34 @@ app.use = function use(fn) {
   fns.forEach(function (fn) {
     // non-express app
     if (!fn || !fn.handle || !fn.set) {
-      return router.use(path, fn);
+      try {
+        return router.use(path, fn);
+      } catch (err) {
+        // Check if this is a path-to-regexp error related to missing parameter names
+        if (err.message && err.message.includes('Missing parameter name')) {
+          // Check if the path contains a bare wildcard (more precise detection)
+          if (typeof path === 'string') {
+            // Detect common problematic wildcard patterns
+            var isBareWildcard = path === '*' ||
+                               path === '/*' ||
+                               /\/\*(?![a-zA-Z_$])/.test(path); // matches /* not followed by identifier chars
+
+            if (isBareWildcard) {
+              var enhancedError = new TypeError(
+                'Invalid middleware path: "' + path + '". ' +
+                'In Express v5, wildcard paths must have named parameters. ' +
+                'Use "/*splat" instead of "*" or "/*". ' +
+                'See Express v5 migration guide for details.'
+              );
+              enhancedError.code = 'INVALID_WILDCARD_PATH';
+              enhancedError.originalError = err;
+              throw enhancedError;
+            }
+          }
+        }
+        // Re-throw the original error if it's not a wildcard issue
+        throw err;
+      }
     }
 
     debug('.use app under %s', path);
@@ -254,7 +281,34 @@ app.use = function use(fn) {
  */
 
 app.route = function route(path) {
-  return this.router.route(path);
+  try {
+    return this.router.route(path);
+  } catch (err) {
+    // Check if this is a path-to-regexp error related to missing parameter names
+    if (err.message && err.message.includes('Missing parameter name')) {
+      // Check if the path contains a bare wildcard (more precise detection)
+      if (typeof path === 'string') {
+        // Detect common problematic wildcard patterns
+        var isBareWildcard = path === '*' ||
+                           path === '/*' ||
+                           /\/\*(?![a-zA-Z_$])/.test(path); // matches /* not followed by identifier chars
+
+        if (isBareWildcard) {
+          var enhancedError = new TypeError(
+            'Invalid route path: "' + path + '". ' +
+            'In Express v5, wildcard routes must have named parameters. ' +
+            'Use "/*splat" instead of "*" or "/*". ' +
+            'See Express v5 migration guide for details.'
+          );
+          enhancedError.code = 'INVALID_WILDCARD_ROUTE';
+          enhancedError.originalError = err;
+          throw enhancedError;
+        }
+      }
+    }
+    // Re-throw the original error if it's not a wildcard issue
+    throw err;
+  }
 };
 
 /**

test/app.all.js

@@ -35,4 +35,59 @@ describe('app.all()', function(){
     .del('/tobi')
     .expect(404, done);
   })
+
+  describe('wildcard error handling', function(){
+    it('should provide helpful error for bare wildcard "*"', function(){
+      var app = express();
+
+      try {
+        app.all('*', function(req, res){
+          res.end('wildcard');
+        });
+        throw new Error('Expected error was not thrown');
+      } catch (err) {
+        if (err.code !== 'INVALID_WILDCARD_ROUTE') {
+          throw err;
+        }
+        // Verify the error message mentions Express v5 and provides solution
+        if (!err.message.includes('Express v5')) {
+          throw new Error('Error message should mention Express v5');
+        }
+        if (!err.message.includes('/*splat')) {
+          throw new Error('Error message should suggest /*splat alternative');
+        }
+      }
+    })
+
+    it('should provide helpful error for "/*" wildcard', function(){
+      var app = express();
+
+      try {
+        app.all('/*', function(req, res){
+          res.end('wildcard');
+        });
+        throw new Error('Expected error was not thrown');
+      } catch (err) {
+        if (err.code !== 'INVALID_WILDCARD_ROUTE') {
+          throw err;
+        }
+        // Verify the error message is helpful
+        if (!err.message.includes('wildcard routes must have named parameters')) {
+          throw new Error('Error message should explain named parameter requirement');
+        }
+      }
+    })
+
+    it('should still work with named wildcard "/*splat"', function(done){
+      var app = express();
+
+      app.all('/*splat', function(req, res){
+        res.end('splat: ' + req.params.splat);
+      });
+
+      request(app)
+        .get('/anything/here')
+        .expect(200, 'splat: anything,here', done);
+    })
+  })
 })

test/app.use.js

@@ -540,3 +540,63 @@ describe('app', function(){
     })
   })
 })
+
+describe('wildcard error handling', function(){
+  it('should provide helpful error for bare wildcard "*" in middleware', function(){
+    var app = express();
+
+    try {
+      app.use('*', function(req, res, next){
+        next();
+      });
+      throw new Error('Expected error was not thrown');
+    } catch (err) {
+      if (err.code !== 'INVALID_WILDCARD_PATH') {
+        throw err;
+      }
+      // Verify the error message mentions Express v5 and provides solution
+      if (!err.message.includes('Express v5')) {
+        throw new Error('Error message should mention Express v5');
+      }
+      if (!err.message.includes('/*splat')) {
+        throw new Error('Error message should suggest /*splat alternative');
+      }
+    }
+  })
+
+  it('should provide helpful error for "/*" wildcard in middleware', function(){
+    var app = express();
+
+    try {
+      app.use('/*', function(req, res, next){
+        next();
+      });
+      throw new Error('Expected error was not thrown');
+    } catch (err) {
+      if (err.code !== 'INVALID_WILDCARD_PATH') {
+        throw err;
+      }
+      // Verify the error message is helpful
+      if (!err.message.includes('wildcard paths must have named parameters')) {
+        throw new Error('Error message should explain named parameter requirement');
+      }
+    }
+  })
+
+  it('should still work with named wildcard "/*splat" in middleware', function(done){
+    var app = express();
+
+    app.use('/*splat', function(req, res, next){
+      req.splatParam = req.params.splat;
+      next();
+    });
+
+    app.get('/*splat', function(req, res){
+      res.end('middleware splat: ' + req.splatParam);
+    });
+
+    request(app)
+      .get('/anything/here')
+      .expect(200, 'middleware splat: anything,here', done);
+  })
+})