✨ Added support to set network interface to bind

packages/core/src/server.js

@@ -114,6 +114,11 @@ export class Server extends http.Server {
     });
   }
 
+  // return host bind address - defaults to 0.0.0.0
+  get host() {
+    return process.env.PERCY_SERVER_HOST || '0.0.0.0';
+  }
+
   // return the listening port or any default port
   get port() {
     return super.address()?.port ?? this.#defaultPort;
@@ -122,7 +127,11 @@ export class Server extends http.Server {
   // return a string representation of the server address
   address() {
     let port = this.port;
-    let host = 'http://localhost';
+    // we need to specifically map 0.0.0.0 to localhost on windows as even though we
+    // can listen to all interfaces using 0.0.0.0 we cant make a request on 0.0.0.0 as
+    // its an invalid ip address as per spec, but unix systems allow request to it and
+    // falls back to localhost
+    let host = `http://${this.host === '0.0.0.0' ? 'localhost' : this.host}`;
     return port ? `${host}:${port}` : host;
   }
 
@@ -131,7 +140,7 @@ export class Server extends http.Server {
     return new Promise((resolve, reject) => {
       let handle = err => off() && err ? reject(err) : resolve(this);
       let off = () => this.off('error', handle).off('listening', handle);
-      super.listen(port, handle).once('error', handle);
+      super.listen(port, this.host, handle).once('error', handle);
     });
   }
 

packages/core/test/discovery.test.js

@@ -1493,7 +1493,7 @@ describe('Discovery', () => {
 
       server2.reply('/img.gif', () => new Promise(resolve => {
         // should not resolve within the test timeout
-        setTimeout(resolve, 10000, [200, 'image/gif', pixel]);
+        setTimeout(resolve, jasmine.DEFAULT_TIMEOUT_INTERVAL + 5000, [200, 'image/gif', pixel]);
       }));
 
       await percy.snapshot({
@@ -1507,8 +1507,13 @@ describe('Discovery', () => {
 
       await percy.idle();
 
-      let paths2 = server2.requests.map(r => r[0]);
-      expect(paths2).toContain('/img.gif');
+      expect(captured[0]).not.toContain(
+        jasmine.objectContaining({
+          attributes: jasmine.objectContaining({
+            'resource-url': 'http://ex.localhost:8001/img.gif'
+          })
+        })
+      );
     });
 
     it('captures remote resources from allowed hostnames', async () => {

packages/core/test/unit/server.test.js

@@ -20,6 +20,26 @@ describe('Unit / Server', () => {
     await new Promise(r => setImmediate(setImmediate, r));
   });
 
+  describe('#host', () => {
+    it('returns the host', async () => {
+      expect(server.host).toEqual('0.0.0.0');
+    });
+
+    describe('with PERCY_SERVER_HOST set', () => {
+      beforeEach(() => {
+        process.env.PERCY_SERVER_HOST = 'localhost';
+      });
+
+      afterEach(() => {
+        delete process.env.PERCY_SERVER_HOST;
+      });
+
+      it('returns correct host', async () => {
+        expect(server.host).toEqual('localhost');
+      });
+    });
+  });
+
   describe('#port', () => {
     it('returns the provided default port when not listening', () => {
       expect(server.port).toEqual(8000);
@@ -33,12 +53,39 @@ describe('Unit / Server', () => {
 
   describe('#address()', () => {
     it('returns the localhost address for the server', () => {
+      // converts default 0.0.0.0 to localhost
       expect(server.address()).toEqual('http://localhost:8000');
     });
 
     it('does not include the port without a default when not listening', () => {
       expect(Server.createServer().address()).toEqual('http://localhost');
     });
+
+    describe('with PERCY_SERVER_HOST set', () => {
+      afterEach(() => {
+        delete process.env.PERCY_SERVER_HOST;
+      });
+
+      describe('when PERCY_SERVER_HOST=localhost', () => {
+        beforeEach(() => {
+          process.env.PERCY_SERVER_HOST = 'localhost';
+        });
+
+        it('it uses localhost correctly', () => {
+          expect(Server.createServer().address()).toEqual('http://localhost');
+        });
+      });
+
+      describe('when PERCY_SERVER_HOST=120.22.12.1', () => {
+        beforeEach(() => {
+          process.env.PERCY_SERVER_HOST = '120.22.12.1';
+        });
+
+        it('it uses 120.22.12.1 correctly', () => {
+          expect(Server.createServer().address()).toEqual('http://120.22.12.1');
+        });
+      });
+    });
   });
 
   describe('#listen([port])', () => {
@@ -60,6 +107,26 @@ describe('Unit / Server', () => {
         Server.createServer().listen(server.port)
       ).toBeRejected();
     });
+
+    describe('with PERCY_SERVER_HOST set', () => {
+      beforeEach(() => {
+        process.env.PERCY_SERVER_HOST = 'localhost';
+      });
+
+      afterEach(() => {
+        delete process.env.PERCY_SERVER_HOST;
+      });
+
+      it('listens on correct host', async () => {
+        expect(server.host).toEqual('localhost');
+        await server.listen();
+        server.route('get', '/test/:path', (req, res) => res.text(req.params.path));
+        await expectAsync(request('/test/foo', 'GET')).toBeResolvedTo('foo');
+
+        // as we have a single network interface locally its not easy to test a negative test
+        // where with a separate network interface we are unable to access server
+      });
+    });
   });
 
   describe('#close()', () => {