Building Blocks have powerful automated testing capabilities using the built-in GitHub actions.

These can be supplemented with additional custom validation and transformation processes as required.


Examples defined in the examples.yaml (inline or by file reference) get validated and included in generated documentation.

Test cases defines in the tests/ subdirectory of each building block get validated. Additional or external tests can be added in tests.yaml as a list of objects with a ref property pointing to the test resource’s location, and optionally defining the output-filename and/or require-fail properties (for more information, see the example tests.yaml file provided in the template and the JSON Schema for tests.yaml.

In each case, the /build/tests/ directory contains a set of validation outputs.

Validation includes the following steps:

  1. JSON schema validation (if JSON schema supplied)
  2. JSON-LD uplift (if JSON and context supplied) ( {testcase}.jsonld and {testcase}.ttl generated)
  3. SHACL validation (if SHACL rules defined)

A summary report is produced at /build/tests/report.html.

This is linked from the generated building block index.

Test resources

The tests directory contains test resources that can be used for performing validation tasks. There are two types of validations:

  • JSON schema
  • RDF / SHACL, if a top-level (i.e., same directory as bblock.json).

Inside the tests directory, 3 types of files will be processed:

  • *.ttl: Turtle RDF files that will be validated against the SHACL rules.
    • SHACL rules are loaded from the shaclRules property inside bblock.json. If a rules.shacl file is found in the Building Block directory it will be used by default. SHACL files must be serialized as Turtle.
  • *.jsonld: JSON-LD files that will be first validated against the Building Block JSON Schema and then against the SHACL rules.
  • *.json: JSON files that will be first validated against the JSON Schema, then “semantically uplifted” by embedding the Building Block’s context.jsonld, and finally validated against the SHACL rules.

If the filename for a test resource ends in -fail (e.g., missing-id-fail.json), validation will only pass if the test fails (JSON SCHEMA, SHACL shapes, etc.); this allows writing negative test cases.

Examples in JSON and JSON-LD format will also be uplifted and validated.

SHACL Validation

SHACL rules can be defined in a rules.shacl file or any other files or URLs in the bblocks.json:

 "shaclRules": [
  "shaclClosures": [

shaclClosures refers to additional files with RDF data required to perform validation - such as checking the types of related objects.

this is particularly useful for relatively small, static vocabularies (e.g. “codelists”) that form part of the specification realised by the building block


In addition to built-in testing capabilities the following online tools can be helpful in developing and debugging different layers of the design:

Hint - to use the JSON Schema validator with a published schema you can create a wrapper such as

  "$ref": ""

(updating version forces the validator to pick up any changes in the published schema.)