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#290 — Coverage: Date.prototype.setXXX functions evaluate all parameters

• bug_id: 290
• creation_ts: 2012-03-04 03:22:00 -0800
• short_desc: Coverage: Date.prototype.setXXX functions evaluate all parameters
• delta_ts: 2012-03-04 03:22:03 -0800
• product: Test262
• component: ECMA-262 Tests
• version: unspecified
• rep_platform: All
• op_sys: All
• bug_status: CONFIRMED
• priority: Normal
• bug_severity: normal
• everconfirmed: true
• reporter: André Bargull
• assigned_to: Dave Fugate

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• commentid: 721
• comment_count: 0
• who: André Bargull
• bug_when: 2012-03-04 03:22:03 -0800

Current engines vary widely in their implementations of the various Date.prototype.setXXX functions.

Some examples per browser:

IE: `new Date(0).setMinutes(void 0, {valueOf:function(){throw 'xxx'}})`
=> returns `NaN` instead of throwing 'xxx'

Opera: `new Date(NaN).setMinutes({valueOf: function(){throw 'xxx'}})`
=> returns `NaN` instead of throwing 'xxx'

Firefox: `new Date(NaN).setMinutes(0, {valueOf:function(){throw 'xxx'}})`
=> returns `NaN` instead of throwing 'xxx'


That means the engines perform different "optimizations" to detect possible invalid date values before evaluating (here: calling ToNumber) all parameters. These optimizations seem to include partial evaluation of the parameters until a NaN value is found and inspection of the current time ([[PrimitiveValue]] of the date object) to check for NaN.