Fix xml:Text and xmlSequence equality comparison

[ravinperera00]

Purpose

The Ballerina specification states the following regarding xml:Text singleton and xml sequences.

# Type for zero or more text characters.
# Built-in subtype of xml.
# Adjacent xml text items are automatically concatenated,
# so an xml sequence belongs to this type if it is a singleton text sequence
# or the empty sequence.
@builtinSubtype
public type Text xml;

This means, when an xml sequence contains only children of xml:Text type, the sequence belongs to the xml:Text type and its value should be equal to an xml:Text value with the concatenation of the children of the sequence. The current implementation does not consider the above two values as equal and the changes included in this PR fixes that.

Fixes #42836

Approach

• Modify the xmlSequence constructor to concatenate adjacent xml:Text elements into one member.
• Change the equals methods of both XmlSequence and XmlText to accept the opposing type as equal if their text values are equal.

Samples

import ballerina/io;

public function main() {
    xml x1 = xml `<a>abc</a><b>def</b>`;
    xml r = xml:map(xml:elements(x1), y => y.getChildren());
    boolean b = (xml `abcdef` == r);
    io:println(b); // true
}

The map method will return an xml sequence containing a single xml:Text member (generated using the concatenation of the two xml:Text elements). This xml sequence will be equal to the xml:Text value of "abcdef".

Check List

• Read the Contributing Guide
• Updated Change Log
• Checked Tooling Support (#)
• Added necessary tests
  • Unit Tests
  • Spec Conformance Tests
  • Integration Tests
  • Ballerina By Example Tests
• Increased Test Coverage
• Added necessary documentation
  • API documentation
  • Module documentation in Module.md files
  • Ballerina By Examples

[codecov]

Codecov Report

Attention: Patch coverage is 93.10345% with 2 lines in your changes missing coverage. Please review.

Project coverage is 77.35%. Comparing base (207d34e) to head (f3b175e).
Report is 30 commits behind head on master.

Files with missing lines	Patch %	Lines
...ballerina/runtime/internal/values/XmlSequence.java	95.83%	0 Missing and 1 partial ⚠️
.../io/ballerina/runtime/internal/values/XmlText.java	80.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #43074      +/-   ##
============================================
+ Coverage     77.30%   77.35%   +0.04%     
- Complexity    58541    58599      +58     
============================================
  Files          3460     3460              
  Lines        220070   220111      +41     
  Branches      28909    28916       +7     
============================================
+ Hits         170136   170273     +137     
+ Misses        40524    40423     -101     
- Partials       9410     9415       +5     

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[github-actions]

This PR has been open for more than 15 days with no activity. This will be closed in 3 days unless the stale label is removed or commented.

[github-actions]

Closed PR due to inactivity for more than 18 days.

[github-actions]

This PR has been open for more than 15 days with no activity. This will be closed in 3 days unless the stale label is removed or commented.

[gimantha]

@ravinperera00 The build is failing

[warunalakshitha]

LGTM