plone.app.discussion/plone/app/discussion/tests/qunit/equiv.js

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// Tests for equality any JavaScript type and structure without unexpected results.
// Discussions and reference: http://philrathe.com/articles/equiv
// Test suites: http://philrathe.com/tests/equiv
// Author: Philippe Rath <prathe@gmail.com>
window.equiv = function () {
var innerEquiv; // the real equiv function
var callers = []; // stack to decide between skip/abort functions
// Determine what is o.
function hoozit(o) {
if (typeof o === "string") {
return "string";
} else if (typeof o === "boolean") {
return "boolean";
} else if (typeof o === "number") {
if (isNaN(o)) {
return "nan";
} else {
return "number";
}
} else if (typeof o === "undefined") {
return "undefined";
// consider: typeof null === object
} else if (o === null) {
return "null";
// consider: typeof [] === object
} else if (o instanceof Array) {
return "array";
// consider: typeof new Date() === object
} else if (o instanceof Date) {
return "date";
// consider: /./ instanceof Object;
// /./ instanceof RegExp;
// typeof /./ === "function"; // => false in IE and Opera,
// true in FF and Safari
} else if (o instanceof RegExp) {
return "regexp";
} else if (typeof o === "object") {
return "object";
} else if (o instanceof Function) {
return "function";
}
}
// Call the o related callback with the given arguments.
function bindCallbacks(o, callbacks, args) {
var prop = hoozit(o);
if (prop) {
if (hoozit(callbacks[prop]) === "function") {
return callbacks[prop].apply(callbacks, args);
} else {
return callbacks[prop]; // or undefined
}
}
}
var callbacks = function () {
// for string, boolean, number and null
function useStrictEquality(b, a) {
return a === b;
}
return {
"string": useStrictEquality,
"boolean": useStrictEquality,
"number": useStrictEquality,
"null": useStrictEquality,
"undefined": useStrictEquality,
"nan": function (b) {
return isNaN(b);
},
"date": function (b, a) {
return hoozit(b) === "date" && a.valueOf() === b.valueOf();
},
"regexp": function (b, a) {
return hoozit(b) === "regexp" &&
a.source === b.source && // the regex itself
a.global === b.global && // and its modifers (gmi) ...
a.ignoreCase === b.ignoreCase &&
a.multiline === b.multiline;
},
// - skip when the property is a method of an instance (OOP)
// - abort otherwise,
// initial === would have catch identical references anyway
"function": function () {
var caller = callers[callers.length - 1];
return caller !== Object &&
typeof caller !== "undefined";
},
"array": function (b, a) {
var i;
var len;
// b could be an object literal here
if ( ! (hoozit(b) === "array")) {
return false;
}
len = a.length;
if (len !== b.length) { // safe and faster
return false;
}
for (i = 0; i < len; i++) {
if( ! innerEquiv(a[i], b[i])) {
return false;
}
}
return true;
},
"object": function (b, a) {
var i;
var eq = true; // unless we can proove it
var aProperties = [], bProperties = []; // collection of strings
// comparing constructors is more strict than using instanceof
if ( a.constructor !== b.constructor) {
return false;
}
// stack constructor before traversing properties
callers.push(a.constructor);
for (i in a) { // be strict: don't ensures hasOwnProperty and go deep
aProperties.push(i); // collect a's properties
if ( ! innerEquiv(a[i], b[i])) {
eq = false;
}
}
callers.pop(); // unstack, we are done
for (i in b) {
bProperties.push(i); // collect b's properties
}
// Ensures identical properties name
return eq && innerEquiv(aProperties.sort(), bProperties.sort());
}
};
}();
innerEquiv = function () { // can take multiple arguments
var args = Array.prototype.slice.apply(arguments);
if (args.length < 2) {
return true; // end transition
}
return (function (a, b) {
if (a === b) {
return true; // catch the most you can
} else if (typeof a !== typeof b || a === null || b === null || typeof a === "undefined" || typeof b === "undefined") {
return false; // don't lose time with error prone cases
} else {
return bindCallbacks(a, callbacks, [b, a]);
}
// apply transition with (1..n) arguments
})(args[0], args[1]) && arguments.callee.apply(this, args.splice(1, args.length -1));
};
return innerEquiv;
}(); // equiv