HttpProvider error handling improved

packages/web3-core-method/tests/src/validators/TransactionReceiptValidatorTest.js

@@ -39,7 +39,7 @@ describe('TransactionReceiptValidatorTest', () => {
 
     it('calls validate and returns true with undefined status property', () => {
         delete receipt.status;
-        
+
         Utils.hexToNumber.mockReturnValueOnce(110);
 
         method.parameters = [

packages/web3-core-subscriptions/src/index.js

@@ -45,4 +45,3 @@ export SyncingSubscription from './subscriptions/eth/SyncingSubscription';
 
 // Shh
 export MessagesSubscription from './subscriptions/shh/MessagesSubscription';
-

packages/web3-providers/src/providers/HttpProvider.js

@@ -144,11 +144,17 @@ export default class HttpProvider {
                     this.connected = true;
                 }
 
-                if (request.readyState === 4 && request.status === 200) {
-                    try {
-                        return resolve(JSON.parse(request.responseText));
-                    } catch (error) {
-                        reject(new Error(`Invalid JSON as response: ${request.responseText}`));
+                if (request.readyState === 4) {
+                    if (request.status === 200) {
+                        try {
+                            return resolve(JSON.parse(request.responseText));
+                        } catch (error) {
+                            reject(new Error(`Invalid JSON as response: ${request.responseText}`));
+                        }
+                    }
+
+                    if (this.isInvalidHttpEndpoint(request)) {
+                        reject(new Error(`Connection refused or URL couldn't be resolved: ${this.host}`));
                     }
                 }
             };
@@ -170,4 +176,17 @@ export default class HttpProvider {
             }
         });
     }
+
+    /**
+     * Checks if the error `net::ERR_NAME_NOT_RESOLVED` or `net::ERR_CONNECTION_REFUSED` will appear.
+     * 
+     * @method isInvalidHttpEndpoint
+     *
+     * @param {Object} request
+     *
+     * @returns {Boolean}
+     */
+    isInvalidHttpEndpoint(request) {
+        return request.response === null && request.status === 0;
+    }
 }

packages/web3-providers/tests/src/providers/HttpProviderTest.js

@@ -225,6 +225,34 @@ describe('HttpProviderTest', () => {
         expect(xhrMock.send).toHaveBeenCalledWith('{"id":"0x0"}');
     });
 
+    it('calls sendPayload and returns with a rejected promise because of an not existing http endpoint', async () => {
+        new XHR();
+        const xhrMock = XHR.mock.instances[0];
+
+        xhrMock.readyState = 4;
+        xhrMock.status = 0;
+        xhrMock.response = null;
+
+        providersModuleFactoryMock.createXMLHttpRequest.mockReturnValueOnce(xhrMock);
+
+        setTimeout(() => {
+            xhrMock.onreadystatechange();
+        }, 1);
+
+        await expect(httpProvider.sendPayload({id: '0x0'})).rejects.toThrow(
+            `Connection refused or URL couldn't be resolved: ${httpProvider.host}`
+        );
+
+        expect(providersModuleFactoryMock.createXMLHttpRequest).toHaveBeenCalledWith(
+            httpProvider.host,
+            httpProvider.timeout,
+            httpProvider.headers,
+            httpProvider.agent
+        );
+
+        expect(xhrMock.send).toHaveBeenCalledWith('{"id":"0x0"}');
+    });
+
     it('calls sendPayload and returns with a rejected promise because of the exceeded timeout', async () => {
         new XHR();
         const xhrMock = XHR.mock.instances[0];