Creating Integration Tests for Oracle-to-PostgreSQL Migration

Step 3: Create seed data

• Follow seed file location and naming conventions from the existing project.
• Reuse existing seed files when possible.
• Avoid TRUNCATE TABLE — keep existing database data intact.
• Do not commit seed data; tests run in transactions that roll back.
• Ensure seed data does not conflict with other tests.
• Load and verify seed data before assertions depend on it.

Step 4: Write test cases

• Inherit from the base test class to get automatic transaction create/rollback.
• Assert logical outputs (rows, columns, counts, error types), not platform-specific messages.
• Assert specific expected values — never assert that a value is merely non-null or non-empty when a concrete value is available from seed data.
• Avoid testing code paths that do not exist or asserting behavior that cannot occur.
• Avoid redundant assertions across tests targeting the same method.

Step 5: Review determinism

Re-examine every assertion against non-null values. Confirm each is deterministic against the seeded data. Fix any assertion that depends on database state outside the test's control.

Key Constraints

• Oracle is the golden source — tests capture Oracle's expected behavior.
• DB-agnostic assertions — no platform-specific error messages or syntax in assertions.
• Seed only against Oracle — test project will be migrated to PostgreSQL later.
• Scoped to one project — do not create tests for artifacts outside the target project.