The real BigQuery engine
No emulator: the SQL behaves exactly as in production, scripts, MERGE and procedures included.
BigTesty
Integration tests for BigQuery, on the real engine and a short-lived infrastructure.
Given / When / Then
Test files in YAML or JSON: load rows, run the SQL under test, assert on query results or table contents.
Isolated and ephemeral
Each scenario of each run gets its own datasets, created and destroyed by BigTesty. Run in parallel, safely.
CLI and pytest
bigtesty test or pytest: one test per scenario, typed comparison and readable diffs.