Re: [xsl] Does it make sense to collect elements with a certain value then assert that the elements I've collected have that certain value?

["Dimitre Novatchev dnovatchev@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

> Does it make sense to verify that every <row> element in
$nav-records-for-this-airport
> has an ARPT_IDENT that matches $airport-id? Is there a benefit to this
assert:

No, unless you are testing the correctness of the XPath processor itself.

Such an assert could though be useful if you are passing this as a
parameter to someone else's code and this person doesn't know you at all,
or enough to trust you - a case that often happens in 3rd-party library
modules.

Thanks,
Dimitre


On Wed, Jul 31, 2024 at 6:58b/AM Roger L Costello costello@xxxxxxxxx <
xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:

> Hi Folks,
>
> $airport-id holds the identifier of an airport.
>
> I use $airport-id to collect <row> elements in $airports-nav-records with
> a matching ARPT_IDENT:
>
> <xsl:variable name="nav-records-for-this-airport"
>                        select="$airports-nav-records//row[ARPT_IDENT eq
> $airport-id]"
>                        as="element(row)*"/>
>
> Does it make sense to verify that every <row> element in
> $nav-records-for-this-airport has an ARPT_IDENT that matches $airport-id?
> Is there a benefit to this assert:
>
> <xsl:assert test="every $i in $nav-records-for-this-airport satisfies
> $i/ARPT_IDENT eq $airport-id "/>
>
> To my way of thinking, there is no benefit. I collected <row> elements
> with a matching ARPT_IDENT, then the assert tests that the collected <row>
> elements have a matching ARPT_IDENT. The assert seems
> pointless/redundant/useless/wasteful. Am I missing something?
>
> Here's the assert in context:
>
> <xsl:for-each select="$airports/*/row">
>         <xsl:variable name="airport-id"
>                                select="ARPT_IDENT"
>                                as="xs:string"/>
>         <xsl:variable name="nav-records-for-this-airport"
>
>  select="$airports-nav-records//row[ARPT_IDENT eq $airport-id]"
>                                as="element(row)*"/>
>         <xsl:assert test="every $i in $nav-records-for-this-airport
> satisfies $i/ARPT_IDENT eq $airport-id "/>