emit error events instead of throwing Error

felicienfrancois · felicienfrancois · commit 0bd6cace6e89 · 2016-02-24T17:58:27.000+01:00
Done for all operation that may be done asynchronously or in a nested
way, in an EventEmitter context.
The change allow to handle errors (by catching error events) while
keeping the original behavior (throwing error) if error events are not
listened
diff --git a/lib/http.js b/lib/http.js
@@ -360,19 +360,19 @@ OutgoingMessage.prototype._finish = function _finish() {
 
 OutgoingMessage.prototype.setHeader = function setHeader(name, value) {
   if (this.headersSent) {
-    throw new Error('Can\'t set headers after they are sent.');
+    return this.emit('error', new Error('Can\'t set headers after they are sent.'));
   } else {
     name = name.toLowerCase();
     if (deprecatedHeaders.indexOf(name) !== -1) {
-      throw new Error('Cannot set deprecated header: ' + name);
+      return this.emit('error', new Error('Cannot set deprecated header: ' + name));
     }
     this._headers[name] = value;
   }
 };
 
 OutgoingMessage.prototype.removeHeader = function removeHeader(name) {
   if (this.headersSent) {
-    throw new Error('Can\'t remove headers after they are sent.');
+    return this.emit('error', new Error('Can\'t remove headers after they are sent.'));
   } else {
     delete this._headers[name.toLowerCase()];
   }
@@ -891,7 +891,7 @@ Agent.prototype.request = function request(options, callback) {
 
   if (!options.plain && options.protocol === 'http:') {
     this._log.error('Trying to negotiate client request with Upgrade from HTTP/1.1');
-    throw new Error('HTTP1.1 -> HTTP2 upgrade is not yet supported.');
+    this.emit('error', new Error('HTTP1.1 -> HTTP2 upgrade is not yet supported.'));
   }
 
   var request = new OutgoingRequest(this._log);
diff --git a/lib/protocol/stream.js b/lib/protocol/stream.js
@@ -625,7 +625,7 @@ Stream.prototype._transition = function transition(sending, frame) {
     // * When sending something invalid, throwing an exception, since it is probably a bug.
     if (sending) {
       this._log.error(info, 'Sending illegal frame.');
-      throw new Error('Sending illegal frame (' + frame.type + ') in ' + this.state + ' state.');
+      return this.emit('error', new Error('Sending illegal frame (' + frame.type + ') in ' + this.state + ' state.'));
     }
 
     // * In case of a serious problem, emitting and error and letting someone else handle it

Original file line number	Diff line number	Diff line change
`@@ -625,7 +625,7 @@ Stream.prototype._transition = function transition(sending, frame) {`
`625`	`625`	`// * When sending something invalid, throwing an exception, since it is probably a bug.`
`626`	`626`	`if (sending) {`
`627`	`627`	`this._log.error(info, 'Sending illegal frame.');`
`628`		`- throw new Error('Sending illegal frame (' + frame.type + ') in ' + this.state + ' state.');`
	`628`	`+ return this.emit('error', new Error('Sending illegal frame (' + frame.type + ') in ' + this.state + ' state.'));`
`629`	`629`	`}`
`630`	`630`
`631`	`631`	`// * In case of a serious problem, emitting and error and letting someone else handle it`