Error in Javascript: Unexpected token (

Question

My page is throwing a javascript error, but I can't figure out why. I'm trying to debug a script that was imported to my client's site. It's throwing the error here:

function(t){
 e._trigger("receive",t,this._uiHash(this))
}

The error is "Uncaught SyntaxError: Unexpected token ("

For context, here is the chunk of code it is located in. Unfortunately I don't really know what purpose these functions serve, but the error is preventing the page from loading correctly. Hopefully this Javascript is enough to give the context, the full script is very long.

_clear: function(e, t) {
 this.reverting = !1;
 var i, n = [];
 if (!this._noFinalSort && this.currentItem.parent().length && this.placeholder
 .before(this.currentItem), this._noFinalSort = null, this.helper[0] ===
 this.currentItem[0]) {
 for (i in this._storedCSS)
 ("auto" === this._storedCSS[i] || "static" === this._storedCSS[
 i]) && (this._storedCSS[i] = "");
 this.currentItem.css(this._storedCSS).removeClass(
 "ui-sortable-helper")
 } else this.currentItem.show();
 for (this.fromOutside && !t && n.push(function(e) {
 this._trigger("receive", e, this._uiHash(this.fromOutside))
 }), !this.fromOutside && this.domPosition.prev === this.currentItem
 .prev().not(".ui-sortable-helper")[0] && this.domPosition.parent ===
 this.currentItem.parent()[0] || t || n.push(function(e) {
 this._trigger("update", e, this._uiHash())
 }), this !== this.currentContainer && (t || (n.push(function(e) {
 this._trigger("remove", e, this._uiHash())
 }), n.push(function(e) {
 return
 function(t) {
 e._trigger("receive", t, this._uiHash(this))
 }
 }.call(this, this.currentContainer)), n.push(function(e) {
 return
 function(t) {
 e._trigger("update", t, this._uiHash(this))
 }
 }.call(this, this.currentContainer)))), i = this.containers.length -
 1; i >= 0; i--) t || n.push(function(e) {
 return function(t) {
 e._trigger("deactivate", t, this._uiHash(this))
 }
 }.call(this, this.containers[i])), this.containers[i].containerCache
 .over && (n.push(function(e) {
 return
 function(t) {
 e._trigger("out", t, this._uiHash(this))
 }
 }.call(this, this.containers[i])), this.containers[i].containerCache
 .over = 0);
 if (this.storedCursor && (this.document.find("body").css("cursor", this
 .storedCursor), this.storedStylesheet.remove()), this._storedOpacity &&
 this.helper.css("opacity", this._storedOpacity), this._storedZIndex &&
 this.helper.css("zIndex", "auto" === this._storedZIndex ? "" : this
 ._storedZIndex), this.dragging = !1, this.cancelHelperRemoval) {
 if (!t) {
 for (this._trigger("beforeStop", e, this._uiHash()), i = 0; n.length >
 i; i++) n[i].call(this, e);
 this._trigger("stop", e, this._uiHash())
 }
 return this.fromOutside = !1, !1
 }
 if (t || this._trigger("beforeStop", e, this._uiHash()), this.placeholder[
 0].parentNode.removeChild(this.placeholder[0]), this.helper[0] !==
 this.currentItem[0] && this.helper.remove(), this.helper = null, !t
 ) {
 for (i = 0; n.length > i; i++) n[i].call(this, e);
 this._trigger("stop", e, this._uiHash())
 }
 return this.fromOutside = !1, !0
}

If you want to look at the page, it's located here

• Amit.rk3: just a suggestion- you can put your script on jsFiddle and click on JSHint, it highlights all the syntax errors
• Sebastian Simon: Or you could just put your code in JSHint.

Answer 1

Every section of your code that looks like:

 return
 function(t) {
 e._trigger("out", t, this._uiHash(this))
 }

is broken. The rules of JavaScript automatic semicolon insertion are such that those return statements are treated as complete when the parser hits the newline. It has to look like:

 return function(t) {
 e._trigger("out", t, this._uiHash(this))
 }

That may seem astonishing, but it's true. The error you're getting happens because the parser thinks that that function keyword is opening a new function declaration statement, and in such a statement the function name is not optional.