@shexjs/extension-test

The Test semantic-action extension, http://shex.io/extensions/Test/: each print(...) action records the line it was handed -- built from the matched triple's subject/predicate/object or the focus node -- in validator.semActHandler.results["http://shex.io/extensions/Test/"], and fail(...) reports a SemActFailure. It's the shexTest suite's probe for when actions fire; shex-validate attaches the collected lines to a failure report as semActResults.

npm install @shexjs/extension-test
shex-validate --extension @shexjs/extension-test -x schema.shex -d data.ttl -n <node> -s <shape>

require("@shexjs/extension-test").register(validator, {ShExTerm}) installs it on a validator you construct yourself.

@shexjs/extension-test is one of the shex.js packages; installing shex pulls in the whole suite, and its README maps them.