fix: check the format of the event name

A packet like '2[{"toString":"foo"}]' was decoded as:

{
  type: EVENT,
  data: [ { "toString": "foo" } ]
}

Which would then throw an error when passed to the EventEmitter class:

> TypeError: Cannot convert object to primitive value
>    at Socket.emit (node:events:507:25)
>    at .../node_modules/socket.io/lib/socket.js:531:14

History of the isPayloadValid() method:

- added in [78f9fc2](78f9fc2) (v4.0.1, [email protected])
- updated in [1c220dd](1c220dd) (v4.0.4, [email protected])

Backported from 3b78117

index.js

@@ -329,11 +329,10 @@ function decodeString(str) {
  // look up json data
  if (str.charAt(++i)) {
  var payload = tryParse(str.substr(i));
- var isPayloadValid = payload !== false && (p.type === exports.ERROR || isArray(payload));
- if (isPayloadValid) {
+ if (isPayloadValid(p.type, payload)) {
  p.data = payload;
  } else {
- return error('invalid payload');
+ throw new Error("invalid payload");
  }
  }
 
@@ -349,6 +348,26 @@ function tryParse(str) {
  }
 }
 
+function isPayloadValid(type, payload) {
+ switch (type) {
+ case 0: // CONNECT
+ return typeof payload === "object";
+ case 1: // DISCONNECT
+ return payload === undefined;
+ case 4: // ERROR
+ return typeof payload === "string" || typeof payload === "object";
+ case 2: // EVENT
+ case 5: // BINARY_EVENT
+ return (
+ isArray(payload) &&
+ (typeof payload[0] === "string" || typeof payload[0] === "number")
+ );
+ case 3: // ACK
+ case 6: // BINARY_ACK
+ return isArray(payload);
+ }
+}
+
 /**
  * Deallocates a parser's resources
  *

test/arraybuffer.js

@@ -50,7 +50,7 @@ describe('parser', function() {
  it('cleans itself up on close', function() {
  var packet = {
  type: parser.BINARY_EVENT,
- data: [new ArrayBuffer(2), new ArrayBuffer(3)],
+ data: ["foo", new ArrayBuffer(2), new ArrayBuffer(3)],
  id: 0,
  nsp: '/'
  };

test/parser.js

@@ -86,12 +86,20 @@ describe('parser', function(){
  }
  });
 
- it('returns an error packet on parsing error', function(done){
- var decoder = new parser.Decoder();
- decoder.on('decoded', function(packet) {
- expect(packet).to.eql({ type: 4, data: 'parser error: invalid payload' });
- done();
- });
- decoder.add('442["some","data"');
+ it('returns an error packet on parsing error', function(){
+ function isInvalidPayload (str) {
+ expect(function () {
+ new parser.Decoder().add(str)
+ }).to.throwException(/^invalid payload$/);
+ }
+
+ isInvalidPayload('442["some","data"');
+ isInvalidPayload('0/admin,"invalid"');
+ isInvalidPayload("1/admin,{}");
+ isInvalidPayload('2/admin,"invalid');
+ isInvalidPayload("2/admin,{}");
+ isInvalidPayload('2[{"toString":"foo"}]');
+ isInvalidPayload('2[true,"foo"]');
+ isInvalidPayload('2[null,"bar"]');
  });
 });