test(bigquery-jdbc): add IT for PCNT metadata and DefaultDataset delimiters

[keshavdandeva]

b/554045509

This PR introduces integration test coverage for PCNT (Project-Catalog-Namespace-Table) metadata and DefaultDataset configurations to support multi-driver verification across standard GCP and TPC environments.

Instead of asserting against static pre-existing tables, these integration tests dynamically provision and tear down isolated PCNT test tables per test class, ensuring self-contained and reproducible test execution.

Changes

1. ITBase.java

• Configurable PCNT Schema: Added PCNT_SCHEMA with fallback to "bq-drivers-test-warehouse.jdbc_pcnt_test_namespace" and environment variable override support for custom TPC environments.
• Dynamic Table Lifecycle Helpers: Added setUpPcntTable() and cleanUpPcntTable() to create isolated PCNT tables with sample data (id, name) and safely drop them during teardown.

2. ITConnectionTest.java

• Dynamic PCNT Table Lifecycle: Dynamically creates and tears down PCNT_CONN_TEST_TABLE_<rand> in @BeforeAll / @AfterAll.
• testDefaultDatasetColonDelimiter(): Tests 2-tier colon syntax (DefaultDataset=project:dataset) and verifies unqualified query execution against default dataset tables.
• testPcntDefaultDataset2TierNamespace(): Tests 2-tier Lakehouse namespace syntax (DefaultDataset=warehouse.namespace) and executes unqualified queries against PCNT tables.
• testPcntDefaultDataset3TierNamespace(): Tests 3-tier PCNT syntax (DefaultDataset=project:warehouse.namespace) and executes unqualified queries against PCNT tables.

3. ITDatabaseMetadataTest.java

• Dynamic PCNT Table Lifecycle: Dynamically creates and tears down PCNT_METADATA_TEST_TABLE_<rand> in @BeforeAll / @AfterAll.
• testDatabaseMetadataGetSchemasPcnt(): Verifies DatabaseMetaData.getSchemas() accurately enumerates PCNT schema namespaces with correct TABLE_SCHEM and TABLE_CATALOG.
• testDatabaseMetadataGetTablesPcnt(): Verifies DatabaseMetaData.getTables() discovers dynamic PCNT tables with table type TABLE.
• testDatabaseMetadataGetColumnsPcnt(): Verifies DatabaseMetaData.getColumns() accurately extracts column metadata (id, name), types, and ordinal positions.

[gemini-code-assist]

Code Review

This pull request introduces integration tests to verify connection URL parsing with different delimiters (colon and dot) for default datasets, including three-tier namespaces (PCNT). It also adds tests for database metadata retrieval (schemas, tables, and columns) under the PCNT schema. The review feedback suggests removing a redundant null check on the ResultSet in ITConnectionTest in favor of a more robust assertion, and optimizing ITDatabaseMetadataTest by extracting repeated ResultSet lookups into a local variable.

[keshavdandeva]

/gemini review

[gemini-code-assist]

Code Review

This pull request adds integration tests to verify default dataset configurations with colon and dot delimiters, as well as 3-tier namespace (PCNT) support in ITConnectionTest and ITDatabaseMetadataTest. The review feedback suggests extracting duplicated schema and table name constants into a dedicated utility class to prevent tight coupling and duplication across test classes.

[keshavdandeva]

/gemini review

[gemini-code-assist]

Code Review

This pull request adds integration tests for BigQuery JDBC connections and database metadata, covering default dataset delimiters and 3-tier namespaces (PCNT). It also refactors PCNT constants into ITBase for shared use. The review feedback correctly identifies that the new tests use JUnit 5 style assertions (with the message as the last argument) instead of JUnit 4 style (with the message as the first argument), which will cause compilation errors in this codebase.