fix: ignore proxy when bypass return false (#1696)

Author: mistic

lib/Server.js

@@ -381,14 +381,22 @@ class Server {
                 }
               }
 
-              const bypass = typeof proxyConfig.bypass === 'function';
-
-              const bypassUrl =
-                (bypass && proxyConfig.bypass(req, res, proxyConfig)) || false;
-
-              if (bypassUrl) {
+              // - Check if we have a bypass function defined
+              // - In case the bypass function is defined we'll retrieve the
+              // bypassUrl from it otherwise byPassUrl would be null
+              const isByPassFuncDefined =
+                typeof proxyConfig.bypass === 'function';
+              const bypassUrl = isByPassFuncDefined
+                ? proxyConfig.bypass(req, res, proxyConfig)
+                : null;
+
+              if (typeof bypassUrl === 'boolean') {
+                // skip the proxy
+                req.url = null;
+                next();
+              } else if (typeof bypassUrl === 'string') {
+                // byPass to that url
                 req.url = bypassUrl;
-
                 next();
               } else if (proxyMiddleware) {
                 return proxyMiddleware(req, res, next);

test/Proxy.test.js

@@ -23,6 +23,15 @@ const proxyOptionPathsAsProperties = {
       if (/\.html$/.test(req.path)) {
         return '/index.html';
       }
+
+      return null;
+    },
+  },
+  '/proxyfalse': {
+    bypass(req) {
+      if (/\/proxyfalse$/.test(req.path)) {
+        return false;
+      }
     },
   },
 };
@@ -116,6 +125,10 @@ describe('Proxy', () => {
       it('should pass through a proxy when a bypass function returns null', (done) => {
         req.get('/foo.js').expect(200, /Hey/, done);
       });
+
+      it('should not pass through a proxy when a bypass function returns false', (done) => {
+        req.get('/proxyfalse').expect(404, done);
+      });
     });
   });