XSLTest: XSLT easy stylesheet testing

Requirements:

• An XSLT 2 processor, such as Saxon.
• A web browser to view the test reports.

Overview

XSLTest lets you test XSLT transforms and functions using a mix of XSLT code, XSLTest elements that define assertions and test suites and embedded HTML documentation.

An XSLTest suite is an XSLT stylesheet with named templates that generate HTML and also contain XSLTest elements.

The XSLTest framework acts as a compiler: the xsltest.xslt stylesheet translates a test suite into a stylesheet that performs the assertions and generates results in XML format. XSLTest's report.xslt stylesheet translates the results into an HTML report.

XSLTest also provides a stylesheet, test-abort-build.xslt, that fails if the results XML contain any test failures. This is useful for aborting the build when tests fail.

Example tests written with XSLTest can be found here: https://github.com/npryce/courseware-html/tree/master/tests

Test Suite Structure and XML Namespaces

XSLTest elements are defined in the namespace http://www.natpryce.com/xsltest/1.0.

The entry-point to a test suite is a named XSLT template. For example:

<xsl:stylesheet version="2.0"
                xmlns="http://www.w3.org/1999/xhtml" 
                xmlns:html="http://www.w3.org/1999/xhtml" 
                xmlns:xsl="http://www.w3.org/1999/XSL/Transform" 
                xmlns:fn="http://www.w3.org/2005/xpath-functions" 
                xmlns:test="http://www.natpryce.com/xsltest/1.0">

  <xsl:import href="mycode.xslt"/>
  
  <xsl:template name="mycode-tests">
      <test:suite>
          <h1>Tests for My Code</h1>
          
          ... assertions and suites go here ...

      </test:suite>
  </xsl:template>
</xsl:stylesheet>

Example Makefile Rules

The following example Makefile rules implement the XSLTest processing pipeline.

build/testing/%.xslt: src/%-test.xslt
	@mkdir -p $(dir $@)
	saxon -xsl:$(XSLTEST_HOME)/xsltest.xslt -s:$< -o:$@

build/testing/results.xml: $(XSLT_TESTS:tests/%.xslt=build/testing/%.xslt) $(XSLT)
	saxon -xsl:build/testing/all-tests.xslt -it:all-tests -o:$@
    
build/testing/report.html: build/testing/results.xml
	saxon -xsl:$(XSLTEST_HOME)/report.xslt -s:$< -o:$@

# Avoid saxon's slow startup if we can say for sure that no tests failed
check: build/testing/report.html
	@if grep -q -m 1 'result="failed"' build/testing/results.xml; then \
		saxon -xsl:$(XSLTEST_HOME)/test-abort-build.xslt -s:build/testing/results.xml; \
	fi

The rules assume that:

• The variable XSLTEST_HOME refers to the directory containing the XSLTest stylesheets.
• The test suite files all have the suffix -test.xslt and are in the src/ directory alongside the code under test.
• Output is generated into a scratch directory named build/testing.
• There is a single root test suite, named all-tests.xslt, that imports all the other test suites in the test directory.