Bug 117766 – Make createNodeIterator() and createTreeWalker() accept default arguments

• Status: RESOLVED
• Resolution: CONFIGURATION CHANGED
• Component: DOM

[Ryosuke Niwa]

Consider merging https://chromium.googlesource.com/chromium/blink/+/f428315bba882a4ba1b2af42869e477b86b51bf1

In DOM Level 2 Traversal and Range, the arguments to these methods were all
mandatory. In DOM4, however, the arguments except the first one (root node)
became optional. Especially, the |whatToShow| argument has the default value
of 0xFFFFFFFF, which is a bitmask meaning that the all kinds of nodes will be
accepted. In contrast, in our current implementation, |whatToShow| argument
is defaulted to zero when it is omitted. This means that all kinds of nodes
should be filtered, which is totally useless for users.

This change updates Document.createNodeIterator() and createTreeWalker() so
they can accept default arguments properly. The potential risk of this change
is low, because omitting the |whatToShow| argument was meaningless with our
old implementation. Mozilla also implements this default argument, so I
assume it is safe to follow the recent specification.

Additionally, this change removes |expandEntityReferences| flag from these
methods' implementation. This flag first appeared in the DOM2 Traversal
specification, but later got removed in DOM4. This flag was never implemented
and was actually ignored. To keep compatibility, this flag is still accepted
when specified in createNodeIterator() and createTreeWalker() methods, so this
change does not affect the behavior.

[Ahmad Saleem]

Test Cases Results:

<<< TreeWalker-basic.html >>>

**** Safari Technology Preview 151 ****


PASS Construct a TreeWalker by document.createTreeWalker(). 
FAIL Give an invalid root node to document.createTreeWalker(). assert_throws: function "function () { document.createTreeWalker(null); }" threw object "TypeError: Argument 1 ('root') to Document.createTreeWalk..." that is not a DOMException NOT_SUPPORTED_ERR: property "code" is equal to undefined, expected 9
PASS Walk over nodes. 

**** Chrome Canary 106 ****

PASS Construct a TreeWalker by document.createTreeWalker(). 
FAIL Give an invalid root node to document.createTreeWalker(). assert_throws: function "function () { document.createTreeWalker(null); }" threw object "TypeError: Failed to execute 'createTreeWalker' on 'Docum..." that is not a DOMException NOT_SUPPORTED_ERR: property "code" is equal to undefined, expected 9
PASS Walk over nodes. 

**** Firefox Nightly 105 ****

PASS Construct a TreeWalker by document.createTreeWalker(). 
FAIL Give an invalid root node to document.createTreeWalker(). assert_throws: function "function () { document.createTreeWalker(null); }" threw object "TypeError: Document.createTreeWalker: Argument 1 is not a..." that is not a DOMException NOT_SUPPORTED_ERR: property "code" is equal to undefined, expected 9
PASS Walk over nodes. 


<<< NodeIterator-basic.html >>>

**** Safari Technology Preview 151 ****

PASS Construct a NodeIterator by document.createNodeIterator(). 
FAIL Give an invalid root node to document.createNodeIterator(). assert_throws: function "function () { document.createNodeIterator(null); }" threw object "TypeError: Argument 1 ('root') to Document.createNodeIter..." that is not a DOMException NOT_SUPPORTED_ERR: property "code" is equal to undefined, expected 9
PASS Iterate over all nodes forward then backward. 
PASS Iterate over all elements forward then backward. 
PASS Iterate over all text nodes forward then backward. 
PASS Iterate over all comment nodes forward then backward. 
PASS Test the behavior of NodeIterator when no nodes match with the given filter. 
PASS Test the behavior of NodeIterator when NodeFilter is specified. 

*** Firefox Nightly 105 ***


PASS Construct a NodeIterator by document.createNodeIterator(). 
FAIL Give an invalid root node to document.createNodeIterator(). assert_throws: function "function () { document.createNodeIterator(null); }" threw object "TypeError: Document.createNodeIterator: Argument 1 is not..." that is not a DOMException NOT_SUPPORTED_ERR: property "code" is equal to undefined, expected 9
PASS Iterate over all nodes forward then backward. 
PASS Iterate over all elements forward then backward. 
PASS Iterate over all text nodes forward then backward. 
PASS Iterate over all comment nodes forward then backward. 
PASS Test the behavior of NodeIterator when no nodes match with the given filter. 
PASS Test the behavior of NodeIterator when NodeFilter is specified. 

*** Chrome Canary 106 ***

PASS Construct a NodeIterator by document.createNodeIterator(). 
FAIL Give an invalid root node to document.createNodeIterator(). assert_throws: function "function () { document.createNodeIterator(null); }" threw object "TypeError: Failed to execute 'createNodeIterator' on 'Doc..." that is not a DOMException NOT_SUPPORTED_ERR: property "code" is equal to undefined, expected 9
PASS Iterate over all nodes forward then backward. 
PASS Iterate over all elements forward then backward. 
PASS Iterate over all text nodes forward then backward. 
PASS Iterate over all comment nodes forward then backward. 
PASS Test the behavior of NodeIterator when no nodes match with the given filter. 
PASS Test the behavior of NodeIterator when NodeFilter is specified. 

________________

Just wanted to update test results. Thanks!

[Ahmad Saleem]

Created attachment 461757 [details]
Test Case - NodeIterator-basic.html

NodeIterator-basic.html Test Case

[Ahmad Saleem]

Created attachment 461758 [details]
Test Case - TreeWalker-basic.html

TreeWalker-basic.html

[Ryosuke Niwa]

All browsers' behavior match.