XMLMerger can not handle merge of subnodes properly

[jan-vcapgemini]

Expected behavior

As an IDEasy intellij user I expect the merger to merge my jdktables.xml properly.

Actual behavior

The XMLMerger ignores the name() attribute if the parent node and the child node have the same name (not the id).

Steps to reproduce (bug) / Use Case of feature request (enhancement)

1. Try to merge the following example:

root:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<application xmlns:merge="https://github.com/devonfw/IDEasy/merge" merge:strategy="COMBINE">
  <roots>
    <annotationsPath>
      <root type="composite" merge:id="name()">
        <root type="simple" name="test"/>
      </root>
    </annotationsPath>
  </roots>
</application>

target:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<application>
  <roots>
    <annotationsPath>
      <root type="composite">
        <root type="simple" name="test2"/>
      </root>
    </annotationsPath>
  </roots>
</application>

UPDATE/Question: What if we add merge:id="@name" to the inner root

Related/Dependent Issues

Blocks: #582

Comments/Hints:

Affected version:

• IDEasy: 2024.09.002-beta-SNAPSHOT
• OS: Windows

[alfeilex]

In our case, using to the OVERRIDE strategy to update the jdktables.xml would work in a way that the already existing JDKS are overridden and new JDKS are added to the document.

But this doesn't solve the case if we want to keep manually added JDKS in our target jdktables.xml file.

To handle this case my assumption was to use the COMBINE strategy with merge:id="@url" for the root elements. But this leads to wrong behaviour since the parent is also named root. If I change the parent root to roots, will get the desired output, if my understanding if it is correct.

Example:
source:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<application xmlns:merge="https://github.com/devonfw/IDEasy/merge" merge:strategy="COMBINE">
  <roots type="composite" merge:id="name()">
    <root url="jrt://$[IDE_HOME]/software/java!/java.datatransfer" type="simple" merge:id="@url"/>
    <root url="jrt://$[IDE_HOME]/software/java!/java.logging" type="simple"/>
    <root url="jrt://$[IDE_HOME]/software/java!/java.management" type="simple"/>
    <root url="jrt://$[IDE_HOME]/software/java!/java.management.rmi" type="simple"/>
  </roots>
</application>

target:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<application>
  <roots type="composite">
    <root url="jrt://$[IDE_HOME]/software/java!/java.instrument" type="simple"/>
    <root url="jrt://$[IDE_HOME]/software/java!/java.management" type="simple"/>
    <root url="jrt://$[IDE_HOME]/software/java!/java.management.rmi" type="simple"/>
  </roots>
</application>

result:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<application>
  <roots type="composite">
    <root url="jrt://$[IDE_HOME]/software/java!/java.instrument" type="simple"/>
    <root url="jrt://$[IDE_HOME]/software/java!/java.management" type="simple"/>
    <root url="jrt://$[IDE_HOME]/software/java!/java.management.rmi" type="simple"/>
    <root url="jrt://$[IDE_HOME]/software/java!/java.datatransfer" type="simple"/>
    <root url="jrt://$[IDE_HOME]/software/java!/java.logging" type="simple"/>
  </roots>
</application>

As you can see the JDKS of the target remains and the JDKS that are missing from source are added.

Without changing the root element this error occurs:

java.lang.IllegalStateException: 3 matches found when trying to match element /application/root/root

Most likely, the identification of the elements is incorrect due to merge:id="name() in the parent root

[alfeilex]

I also tried to use different strategies but I doesn't work, because the strategy in the root of the document (in this case application) is always used. What I am doing wrong here?

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<application xmlns:merge="https://github.com/devonfw/IDEasy/merge" merge:strategy="OVERRIDE">
  <root type="composite" merge:strategy="COMBINE">
    <root url="jrt://$[IDE_HOME]/software/java!/java.datatransfer" type="simple" merge:id="@url"/>
    <root url="jrt://$[IDE_HOME]/software/java!/java.logging" type="simple"/>
    <root url="jrt://$[IDE_HOME]/software/java!/java.management" type="simple"/>
    <root url="jrt://$[IDE_HOME]/software/java!/java.management.rmi" type="simple"/>
  </root>
</application>

[alfeilex]

So finally, the OVERRIDE strategy should be used to merge jdk.table.xml. That strategy will override the whole document, so the target jdk.table.xml file is up-to-date.

When the user has added JDKS in the file manually, then that files are overridden as well.

Example:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<application xmlns:merge="https://github.com/devonfw/IDEasy/merge" merge:strategy="OVERRIDE">
  <component name="ProjectJdkTable">
    <jdk version="2">
      <name value="Java"/>
      <type value="JavaSDK"/>
       ...
       ...

Unblocks issue: #582