7 Best Practices for Writing dbForge Unit Tests for SQL Server

3. Tests inconsistent (pass locally, fail in CI)

Common causes:

• Different database state or schema between environments
• Missing test data or seed scripts
• Permissions differences
• Timezone or locale differences

Fixes:

1. Use repeatable setup — Always run schema migration and data seeding scripts before tests to ensure consistent state.
2. Run tests against a dedicated test database — Avoid shared databases that other processes modify.
3. Check user permissions — Ensure CI service account has the same DB permissions as local tester.
4. Normalize environment — Use the same SQL Server version, collation, and regional settings in CI.

4. Assertion failures due to data formatting or types

Common causes:

• Mismatched data types (e.g., datetime precision)
• String collation or trailing whitespace
• Floating point precision differences

Fixes:

1. Normalize values in assertions — Trim strings, round floats, or compare within a tolerance:

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   ASSERT ABS(expected - actual) < 0.0001 

2. Use explicit casts/formatting — Convert datetimes to a single precision or string format before comparing.
3. Set deterministic test data — Avoid relying on GETDATE() or non-deterministic values; inject fixed timestamps.

5. Setup/teardown scripts fail or leave artifacts

Common causes:

• Errors in cleanup scripts
• Transaction scope not handled correctly
• Foreign key constraints block deletions

Fixes:

1. Use transactions with rollback — Wrap test changes in transactions and roll back at end when appropriate.
2. Disable constraints during teardown carefully — Temporarily disable foreign keys or delete in dependency order.
3. Log errors in scripts — Capture and surface setup/teardown errors so failures aren’t silent.
4. Idempotent scripts — Make setup/teardown safe to run multiple times (check exists before create/drop).

6. Test explorer not discovering tests

Common causes:

• Incorrect test project configuration
• Test files not saved or compiled
• Filters in test explorer hiding tests

Fixes:

1. Rebuild test project — Ensure the project compiles without errors.
2. Check naming conventions — Ensure test procedures/classes follow dbForge’s discovery patterns.
3. Refresh Test Explorer — Use the refresh action and confirm no filters are applied.
4. Verify test attributes — Confirm tests are decorated or configured as dbForge expects.

7. Permission denied errors during test execution

Common causes:

• Insufficient permissions for DDL/DML actions
• Attempts to access system databases
• UAC or OS-level permission blocks

Fixes:

1. Grant necessary permissions — Ensure test user has CREATE, ALTER, INSERT, UPDATE, DELETE as needed on the test database.
2. Avoid system DBs — Run tests in user databases, not master or msdb.
3. Run dbForge with elevated rights if needed — Only when safe and compliant with security policies.

8. Problems with mocking or stubbing dependencies

Common causes:

• Tests relying on external services or linked servers
• Incomplete isolation of dependencies

Fixes:

1. Use test doubles — Replace external calls with mock tables/stored procedures in the test DB.
2. Isolate external integrations — Use dependency injection patterns where possible or wrapper procedures you can stub.
3. Simulate failures deterministically — Create controlled error conditions to test error handling.

Quick checklist to resolve most issues

• Rebuild and refresh test project.
• Confirm SQL Server instance, network, and credentials.
• Run schema migrations and seed data before tests.
• Increase timeouts and disable parallel execution when debugging.
• Use transactions/rollback for cleanup.
• Ensure test account permissions and environment parity with CI.

If you want, I can generate specific setup/teardown scripts, a CI pipeline example (Azure DevOps/GitHub Actions), or example assertions for a failing test—tell me which and I’ll provide it.