114465 2013-04-11 14:21:44 -0700 [DOM] Non-callback interface objects without [NoInterfaceObject] should be instanceof Function 2022-08-15 02:32:26 -0700 1 1 1 Unclassified WebKit DOM 528+ (Nightly build) Unspecified Unspecified RESOLVED CONFIGURATION CHANGED http://dev.w3.org/2006/webapi/WebIDL/#interface-object P2 Normal --- 1 glenn webkit-unassigned ahmad.saleem792 apavlov ap arv ashvayka bfulgham cdumez ggaren heycam oliver rniwa oldest_to_newest 874159 0 glenn 2013-04-11 14:21:44 -0700 WebIDL 4.4 [1] specifies that non-callback interfaces that are not declared with [NoInterfaceObject] should satisfy: (1) a corresponding property must exist on the ECMAScript global object; (2) the name of the property is the identifier of the interface; (3) its value is an object called the interface object; and (4) the interface object for a given non-callback interface is a function object. In some W3C CSSOM incoming tests [2], one can see how CSSStyleDeclaration is not instanceof Function on Safari, but works on FF and Opera. This extends to other HTML, etc interface types as well. [1] http://www.w3.org/TR/WebIDL/#es-interfaces [2] http://hg.csswg.org/test/raw-file/default/contributors/gadams/incoming/cssom/cssstyledeclaration-interface.xht See also comments in bug 114457. 874176 1 arv 2013-04-11 14:40:53 -0700 http://dev.w3.org/2006/webapi/WebIDL/#interface-object "The internal [[Prototype]] property of an interface object for a callback interface must be the Object.prototype object." We are plannin to change this in the spirit of ES6 so that the [[Prototype]] points to the super interface object and if there is no such interface object it will point to Function.prototype. 874189 2 glenn 2013-04-11 14:54:34 -0700 (In reply to comment #1) > http://dev.w3.org/2006/webapi/WebIDL/#interface-object > > "The internal [[Prototype]] property of an interface object for a callback interface must be the Object.prototype object." > > We are plannin to change this in the spirit of ES6 so that the [[Prototype]] points to the super interface object and if there is no such interface object it will point to Function.prototype. This bug is about non-callback interfaces, so the above doesn't seem to apply. What applies is: (1) "The interface object for a given non-callback interface is a function object." (2) "If an object is defined to be a function object, then it has characteristics as follows: Its [[Prototype]] internal property is the Function prototype object." 874201 3 arv 2013-04-11 15:08:27 -0700 I agree that this is the desired behavior but clearly WebIDL has bugs here. The callable interface objects are not instanceof Function, but the non callable are??? I'll file some WebIDL bugs. 874221 4 heycam 2013-04-11 15:23:00 -0700 Maybe callback interfaces and callable interfaces are being confused here. Callback interfaces, i.e. callback interface Something { ... }; never have interface objects, so there is no need to define their interface objects are Function objects or not. Callback interfaces are used so that APIs can call back into native objects that "implement" the interface. All non-callback interface objects ("non-callback interface" = "interfaces that platform objects can implement"), whether they are declared with [Constructor] or not, are Function objects and are thus callable. 874228 5 heycam 2013-04-11 15:35:04 -0700 Sorry, callback interfaces *can* get interface objects, but only when there are consts declared on them. So: callback interface Something { const long x = 1; void f(); }; There exists window.Something, which has a single property "x". window.Something is not a Function object. 1888435 6 ahmad.saleem792 2022-08-02 10:23:40 -0700 I can see a bug in WPT to add these test but it is still open: https://github.com/web-platform-tests/wpt/issues/7184 Plus Chrome has marked related bug as WONTFIX: https://bugs.chromium.org/p/chromium/issues/detail?id=230610 Is something needed on Safari end? I jus wanted to update, appreciate if someone update and mark this bug according (similarly bug mentioned in Comment 0 beside this one)? Thanks! 1891304 7 ashvayka 2022-08-15 02:32:26 -0700 (In reply to Ahmad Saleem from comment #6) > Plus Chrome has marked related bug as WONTFIX: > > https://bugs.chromium.org/p/chromium/issues/detail?id=230610 Same comment for WebKit: we match the updated spec (https://github.com/whatwg/webidl/pull/313). Even non-constructible interfaces are instances of a Function. > I can see a bug in WPT to add these test but it is still open: > > https://github.com/web-platform-tests/wpt/issues/7184 I'm sure we have a tests of own for this.