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_.isEqual: Ensure commutative equality for dates and RegExps.

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This commit is contained in:
Kit Goncharov
2011-07-13 14:24:28 -06:00
parent 365eea6aa7
commit a12d0035cb
2 changed files with 20 additions and 11 deletions
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4
test/objects.js
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@@ -79,9 +79,13 @@ $(document).ready(function() {
ok(NaN != NaN, 'NaN is not equal to NaN (native equality)');
ok(NaN !== NaN, 'NaN is not equal to NaN (native identity)');
ok(_.isEqual(NaN, NaN), 'NaN is equal to NaN');
ok(!_.isEqual(5, NaN), '`5` is not equal to `NaN`');
ok(!_.isEqual(false, NaN), '`false` is not equal to `NaN`');
ok(_.isEqual(new Date(100), new Date(100)), 'identical dates are equal');
ok(_.isEqual((/hello/ig), (/hello/ig)), 'identical regexes are equal');
ok(!_.isEqual({source: '(?:)', global: true, multiline: true, ignoreCase: true}, /(?:)/gim), 'RegExp-like objects and RegExps are not equal');
ok(!_.isEqual(null, [1]), 'a falsy is never equal to a truthy');
ok(!_.isEqual(undefined, null), '`undefined` is not equal to `null`');
ok(_.isEqual({isEqual: function () { return true; }}, {}), 'first object implements `isEqual`');
ok(_.isEqual({}, {isEqual: function () { return true; }}), 'second object implements `isEqual`');
ok(!_.isEqual({x: 1, y: undefined}, {x: 1, z: 2}), 'objects with the same number of undefined keys are not equal');

27
underscore.js
View File

@@ -595,7 +595,8 @@
// Internal recursive comparison function.
function eq(a, b, stack) {
// Identical objects are equal.
// Identical objects are equal. `0 === -0`, but they aren't identical.
// See the Harmony `egal` proposal: http://wiki.ecmascript.org/doku.php?id=harmony:egal.
if (a === b) return a !== 0 || 1 / a == 1 / b;
// A strict comparison is necessary because `null == undefined`.
if (a == null) return a === b;
@@ -604,17 +605,21 @@
if (typeA != typeof b) return false;
// The type comparison above prevents unwanted type coercion.
if (a == b) return true;
// Ensure that both values are truthy or falsy.
// Optimization; ensure that both values are truthy or falsy.
if ((!a && b) || (a && !b)) return false;
// `NaN` values are equal.
if (_.isNaN(a)) return _.isNaN(b);
if (_.isDate(a)) return _.isDate(b) && a.getTime() == b.getTime();
// Compare dates by their millisecond values.
var isDateA = _.isDate(a), isDateB = _.isDate(b);
if (isDateA || isDateB) return isDateA && isDateB && a.getTime() == b.getTime();
// Compare RegExps by their source patterns and flags.
if (_.isRegExp(a)) return _.isRegExp(b) && a.source == b.source &&
a.global == b.global &&
a.multiline == b.multiline &&
a.ignoreCase == b.ignoreCase;
// Recursively compare objects and arrays.
var isRegExpA = _.isRegExp(a), isRegExpB = _.isRegExp(b);
if (isRegExpA || isRegExpB) return isRegExpA && isRegExpB &&
a.source == b.source &&
a.global == b.global &&
a.multiline == b.multiline &&
a.ignoreCase == b.ignoreCase;
// Ensure that both values are objects.
if (typeA != 'object') return false;
// Unwrap any wrapped objects.
if (a._chain) a = a._wrapped;
@@ -629,9 +634,9 @@
while (length--) {
if (stack[length] == a) return true;
}
// Add the object to the stack of traversed objects.
// Add the first object to the stack of traversed objects.
stack.push(a);
// Deep compare the contents.
// Deep compare the two objects.
var size = 0, sizeRight = 0, result = true, key;
for (key in a) {
// Count the expected number of properties.
@@ -646,7 +651,7 @@
}
result = size == sizeRight;
}
// Remove the object from the stack of traversed objects.
// Remove the first object from the stack of traversed objects.
stack.pop();
return result;
}