XQSuite: NullPointerException vs. util:eval()

[mathias-goebel]

the problem

When doing some unit tests, i encountered NPEs testing functions calling imported modules. (it is only a good guess, that this is the cause)
Anyway, when calling exactly the same with string(CALL) => util:eval(), the test will run as expected.

In other words, a test fails for:

declare
    %test:args("/db/apps/sade/docs/about.md") %test:assertXPath('local-name($result) = "div"')
function tests:multiviewer-markdown($docpath) {
    multiviewer:markdown($docpath)
};

<testcase name="multiviewer-markdown" class="tests:multiviewer-markdown">
    <error type="java:java.lang.NullPointerException" message=""/>
</testcase>

…but works when the function uses util:eval:

declare
    %test:args("/db/apps/sade/docs/about.md") %test:assertXPath('local-name($result) = "div"')
function tests:multiviewer-markdown($docpath) {
    util:eval( "multiviewer:markdown($docpath)" )
};

<testcase name="multiviewer-markdown" class="tests:multiviewer-markdown"/>

reproduce/test

So, here are three files you need to test this in eXist (you need the markdown parser installed)

Module with import = /db/apps/module.xqm

xquery version "3.1";
module namespace module="http://exist-db.org/apps/myapp/module";
import module namespace markdown="http://exist-db.org/xquery/markdown";
declare function module:markdown($input as xs:string){
    markdown:parse($input)
};

Test wrapper = /db/apps/test.xqm

xquery version "3.1";
module namespace tests="https://sade.textgrid.de/ns/tests";
import module namespace module="http://exist-db.org/apps/myapp/module" at "/db/apps/module.xqm";
declare namespace test="http://exist-db.org/xquery/xqsuite";

declare
    %test:args("# Hello World") %test:assertXPath('$result//h1[. = "Hello World"]')
function tests:module-markdown-util($string) {
    util:eval( "module:markdown($string)" )
};

declare
    %test:args("# Hello World") %test:assertXPath('$result//h1[. = "Hello World"]')
function tests:module-markdown($string) {
    module:markdown($string)
};

Start the test = /db/apps/test.xq

xquery version "3.1";
import module namespace test="http://exist-db.org/xquery/xqsuite" at "resource:org/exist/xquery/lib/xqsuite/xqsuite.xql";
(: all tests are specified in modules/test.xqm :)
test:suite(
    inspect:module-functions(xs:anyURI("/db/apps/test.xqm"))
)

Test return

<testsuites>
    <testsuite package="https://sade.textgrid.de/ns/tests" timestamp="2018-02-26T12:05:54.213+01:00" failures="0" pending="0" tests="2" time="PT0.004S">
        <testcase name="module-markdown" class="tests:module-markdown">
            <error type="java:java.lang.NullPointerException" message=""/>
        </testcase>
        <testcase name="module-markdown-util" class="tests:module-markdown-util"/>
    </testsuite>
</testsuites>

Context information

• eXist-db 4.0.0
• openjdk version "1.8.0_151"
• OpenJDK Runtime Environment (build 1.8.0_151-8u151-b12-0ubuntu0.17.10.2-b12)
• OpenJDK 64-Bit Server VM (build 25.151-b12, mixed mode)
• Linux
• 64 bit
• No custom changes in e.g. conf.xml