Migration Test

xslt-migrate-test is the proof before the switch. It finds the XML + XSLT pairs of a project, transforms each one with a reference engine (the browser's own XSLT, or libxslt) and with @tradik/xslt-processor, compares the two outputs and reports how many match. It ships in the xslt-migrate-check package next to the checker.

npx -p xslt-migrate-check -p @tradik/xslt-processor -p jsdom xslt-migrate-test .

The library and jsdom are optional peer dependencies: the checker itself stays dependency-free. In a project that already has them installed, npx xslt-migrate-test . is enough; without them the command prints the line above and exits 2. With @tradik/xslt3 installed, the library runs in xsltVersion: "auto" mode and XSLT 2.0/3.0 stylesheets are tested too.

Output

Reference engine: xsltproc (libxslt 10145)

47 transformations tested

MATCH:             44
DIFFERENT OUTPUT:   2
ERROR:              1

Compatibility: 93.6%

invoice.xsl
  Input:     public/invoice.xml
  Expected:  <total>123.00</total>
  Tradik:    <total>123</total>
  At:        /html/body/p/total/text()

Every transformation is one of:

Compatibility is MATCH / (tested − SKIPPED), with one decimal; n/a when nothing was compared. A block follows for every result that is not a MATCH; --diff full replaces the first difference with a unified diff of the two outputs.

The pairs

• <?xml-stylesheet?> documents of the project (.xml, .rss, .atom, .rdf) with the stylesheet their href names, also after the migration (the loader line does not change what the stylesheet sees).
• --pairs pairs.json: [{ "xml": "a.xml", "xsl": "a.xsl", "params": { "lang": "en" } }], paths relative to the directory argument.
• --xml a.xml --xsl a.xsl: one pair.

--param name=value (repeatable) passes a top-level parameter to every pair; a list entry's own params win.

Reference engines

In this order, and the report names the one used:

1. Chromium through Playwright, when @playwright/test or playwright is installed in the project (or --browser). The project is served from a private origin, so xsl:include and document() resolve as on the site, and Chromium starts with --enable-blink-features=XSLT, so this keeps working after Chrome 158 turns XSLT off by default. Needs npx playwright install chromium.
2. xsltproc (libxslt, the engine inside Chrome) when it is on PATH, with --stringparam for the parameters.
3. None: a smoke test. The library runs alone and only its errors are reported; every other pair is SKIPPED.

--reference browser|xsltproc|none forces one and exits 2 when it is not available; --browser is --reference browser. When Chromium is found but does not start, the automatic choice falls back to xsltproc with a note on stderr. xsltproc implements XSLT 1.0 only, so XSLT 2.0/3.0 stylesheets show as ERROR against it.

What counts as a difference

Both outputs are parsed with the same parser and compared as trees: XML output with the XML parser (wrapped, since a result may be a fragment), HTML output with jsdom's HTML parser, text output line by line. Not differences:

• attribute order, the XML declaration, a doctype;
• whitespace-only text between elements (indentation) and trailing whitespace;
• the <meta http-equiv="Content-Type"> or <meta charset> element that libxml2 and other serializers add to HTML output.

Text content, element and attribute names, namespaces, attribute values, comments and processing instructions are compared exactly. The output method comes from xsl:output, else HTML when the result starts with <html>.

Options

Exit codes: 0, or 1 below --fail-under (nothing compared counts as 0%); 2 for a bad command line, a missing library or jsdom, an unavailable forced reference engine, a bad pairs file or an HTML file that cannot be written.

The HTML report uses the checker's page style: the counts, the compatibility, and one table row per transformation with its result.

In a pipeline

- run: sudo apt-get install -y xsltproc
- run: npx -p xslt-migrate-check -p @tradik/xslt-processor -p jsdom xslt-migrate-test . --reference xsltproc --fail-under 95

Where it lives

packages/migrate-check/src/compat/ in the repository: pairs.js (discovery), compare.js and nodes.js (the tree comparison), report.js and html.js, engines/ (Tradik, xsltproc, Chromium) and cli.js. The Chromium test runs only with MIGRATE_TEST_BROWSER=1; the xsltproc test is skipped when xsltproc is not installed.