Testing Blocks

Overview

Custom blocks should be tested like any other R code. This 15-minute video walks through writing unit tests for blockr blocks using testthat.

What the video covers

1. Test setup: configure a testthat test file for your block package
2. Testing the expression: verify that your block's core function produces correct output for known inputs
3. Testing inputs: confirm that input constructors create valid UI elements and that default values are sensible
4. Testing edge cases: handle empty data, missing columns, unexpected types, and other boundary conditions
5. Integration testing: connect blocks in a pipeline and verify the end-to-end result

Why test blocks

• Confidence during refactoring: change internals without breaking the interface
• Documentation by example: tests show exactly how a block is expected to behave
• CI/CD readiness: automated tests catch regressions before they reach users

Next steps

• Creating custom blocks: if you haven't built a block yet
• Developer documentation: full blockr.core API reference