chore: add test for attribute order

[ronaldtse]

Metanorma PR checklist

• Breaking changes (list related PRs)
• Documentation update required (create task for this)
• External dependency introduced (documentation update need)
• Gem with native library introduced

[ronaldtse]

@Intelligent2013 I need your help here.

We're using an XSLT stylesheet to normalize XML. However, the attributes are not ordered, which is causing the failure.

Can you please help tweak this XSL file so that it sorts the attributes? Thanks!

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="xml" encoding="ISO-8859-1"/>
  <xsl:param name="indent-increment" select="'   '"/>
  <xsl:template name="newline">
    <xsl:text disable-output-escaping="yes">
</xsl:text>
  </xsl:template>

  <xsl:template match="comment() | processing-instruction()">
    <xsl:param name="indent" select="''"/>
    <xsl:call-template name="newline"/>
    <xsl:value-of select="$indent"/>
    <xsl:copy />
  </xsl:template>

  <xsl:template match="text()">
    <xsl:param name="indent" select="''"/>
    <xsl:call-template name="newline"/>
    <xsl:value-of select="$indent"/>
    <xsl:value-of select="normalize-space(.)"/>
  </xsl:template>

  <xsl:template match="text()[normalize-space(.)='']"/>

  <xsl:template match="*">
    <xsl:param name="indent" select="''"/>
    <xsl:call-template name="newline"/>
    <xsl:value-of select="$indent"/>
    <xsl:choose>
      <xsl:when test="count(child::*) > 0">
        <xsl:copy>
        <xsl:copy-of select="@*"/>
        <xsl:apply-templates select="*|text()">
          <xsl:with-param name="indent" select="concat ($indent, $indent-increment)"/>
        </xsl:apply-templates>
        <xsl:call-template name="newline"/>
        <xsl:value-of select="$indent"/>
        </xsl:copy>
      </xsl:when>
      <xsl:otherwise>
        <xsl:copy-of select="."/>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:template>
</xsl:stylesheet>

[Intelligent2013]

@ronaldtse this is non-trivial task. Regarding the XML spec https://www.w3.org/TR/REC-xml/#sec-starttags:

the order of attribute specifications in a start-tag or empty-element tag is not significant

The XSL doesn't have the instruction to order the attributes. Only way to order the attributes is recreating each manually like this:

<xsl:attribute name="type">
   <xsl:value-of select="@type"/>
</xsl:attribute>
<xsl:attribute name="usage">
   <xsl:value-of select="@usage"/>
</xsl:attribute>

but we need to know the attributes (and order) for for each element.

Regarding the xmlns prefixed attributes on root element, the XSLT processor creates them automatically and don't allow to control them.

[Intelligent2013]

May be for comparing XML files it would be better to use like this https://github.com/postmodern/nokogiri-diff instead of comparison line by line?

[ronaldtse]

Thanks @Intelligent2013 . I can't figure out how nokogiri-diff can work so I'm using the compare-xml gem instead, which works.